diff --git a/docs/dev_control_center.md b/docs/dev_control_center.md
index a645a737..c548e306 100644
--- a/docs/dev_control_center.md
+++ b/docs/dev_control_center.md
@@ -37,6 +37,7 @@ Use these docs as inputs, but treat this file as the decision layer:
 - TUI v2 integration execution plan (current working plan): `docs/tui_v2_integration_execution_plan_2026-03-02.md`
 - TUI v2 mockup gap audit: `docs/tui_v2_mockup_gap_audit_2026-03-02.md`
 - Semantic vector index integration plan: `docs/semantic_vector_index_plan.md`
+- Index0 atlas execution plan: `docs/index0_atlas_execution_plan_2026-03-05.md`
 - Cutover memo: `docs/tui_v2_cutover_decision.md`
 - Security readiness: `docs/security_readiness_checklist.md`
 - Supply-chain integrity: `docs/supply_chain_release_integrity.md`
@@ -79,6 +80,28 @@ Use these docs as inputs, but treat this file as the decision layer:
   - Phase C complete baseline (legacy + TUI v2 semantic workflows and mode toggles)
   - Next: incremental mutation hooks + hybrid quality hardening
 
+### Index0 Atlas Roadmap
+- New architecture/spec track drafted:
+  - `docs/index0_atlas_execution_plan_2026-03-05.md`
+- Phase 0 implementation spec drafted:
+  - `docs/index0_phase0_spec_2026-03-05.md`
+- Phase 1 foundation slice landed:
+  - reserved `_system.index0` namespace normalization
+  - deterministic `index0` merge helper
+  - Nostr manifest optional `index0` metadata support
+  - focused tests in `src/tests/test_index0_core.py`
+- Intent:
+  - add canonical encrypted atlas state inside the existing payload for audit, hierarchy wayfinding, and future KB/chat navigation
+- Key implementation direction:
+  - reserved `_system.index0` namespace inside the synced payload
+  - deterministic merge + checkpointed hash-chain validation
+  - rebuildable wayfinder views layered on top
+- Sequencing:
+  - Phase 0 spec/schema is drafted
+  - Phase 1 foundation is partially implemented
+  - next implementation slice: event emission hooks from entry CRUD/link flows
+  - implementation phases should not preempt current TUI cutover-critical or security-readiness blockers
+
 ## 4) Recommended Next Steps (Priority Order)
 
 1. Execute Phases A-C from `docs/tui_v2_integration_execution_plan_2026-03-02.md`:
@@ -91,6 +114,12 @@ Use these docs as inputs, but treat this file as the decision layer:
 : unified lexical+tag+semantic search integration.
 5. Execute Phase F:
 : final per-board fidelity pass and strict mockup closeout.
+6. Start Index0 Atlas Phase 0 from `docs/index0_atlas_execution_plan_2026-03-05.md`:
+: lock schema, merge contract extension, manifest checkpoint fields, and compaction rules.
+7. After cutover-critical TUI/security slices stabilize, execute Index0 Atlas Phases 1-3:
+: canonical storage, event emission hooks, and manifest checkpoint validation.
+8. After semantic hardening resumes, execute Index0 Atlas Phase 5:
+: atlas read APIs/views and semantic interplay.
 
 ## 5) Next Slice Definition (Recommended Immediate Work)
 
diff --git a/docs/index0_atlas_execution_plan_2026-03-05.md b/docs/index0_atlas_execution_plan_2026-03-05.md
new file mode 100644
index 00000000..8159e62b
--- /dev/null
+++ b/docs/index0_atlas_execution_plan_2026-03-05.md
@@ -0,0 +1,613 @@
+# Index0 Atlas Execution Plan (2026-03-05)
+
+Status: Proposed  
+Branch target: `beta`  
+Scope: Core index payload, Nostr sync, hierarchy navigation, future KB and agent workflows
+
+## 1) Goal
+
+Implement `index0` as the canonical encrypted atlas for SeedPass:
+
+1. record what exists
+2. record what changed
+3. expose deterministic wayfinding state for users and agents
+4. preserve existing SeedPass sync, merge, and security guarantees
+
+Working slogan:
+
+`Index0 is the atlas: it records what exists, what changed, and how to navigate it.`
+
+## 2) Beta Branch Baseline To Reuse
+
+This plan is grounded in the current `beta` branch, not a greenfield design.
+
+Existing contracts already in place:
+
+1. Nostr sync uses manifest + snapshot chunks + deltas:
+   - manifest `30070`
+   - snapshot chunk `30071`
+   - delta `30072`
+   - references: `docs/SPEC.md`, `docs/nostr_setup.md`, `src/nostr/backup_models.py`, `src/nostr/snapshot.py`
+2. Deterministic convergence already exists through `modified_ts_hash_tombstone_v2`:
+   - references: `docs/sync_conflict_contract.md`, `src/seedpass/core/sync_conflict.py`
+3. Retention caps already exist for unbounded metadata growth:
+   - current example: tombstone retention cap in `src/seedpass/core/sync_conflict.py`
+4. Hierarchy and namespace reset are already part of the product model:
+   - key hierarchy: `docs/SPEC.md`
+   - namespace reset / `nostr_account_idx`: `docs/nostr_namespace_reset.md`, `src/seedpass/core/state_manager.py`
+5. Entry graph links already provide typed relationships between artifacts:
+   - reference: `docs/entry_graph.md`
+6. Semantic retrieval already has the correct architectural shape for derived caches:
+   - local-only derived index, not canonical sync state
+   - reference: `docs/semantic_vector_index_plan.md`
+
+## 3) Core Design Decision
+
+`index0` should live inside the existing encrypted index payload and ride the existing snapshot/delta pipeline.
+
+Recommendation for `beta`:
+
+1. Do not create a separate database or alternate sync protocol.
+2. Do not put `index0` records into the user `entries` map initially.
+3. Add a reserved top-level system namespace in the canonical payload, then expose entry-like adapters later if needed.
+
+Recommended payload shape:
+
+```json
+{
+  "schema_version": 3,
+  "entries": {},
+  "_sync_meta": {},
+  "_system": {
+    "index0": {
+      "schema_version": 1,
+      "events": {},
+      "checkpoints": {},
+      "canonical_views": {},
+      "view_manifest": {},
+      "heads": {},
+      "stats": {}
+    }
+  }
+}
+```
+
+## 4) Why `_system.index0` Instead Of User `entries`
+
+The current `beta` code strongly assumes user entries are numeric IDs:
+
+1. create/update flows allocate integer IDs in `src/seedpass/core/entry_management.py`
+2. retrieve/modify/list paths index into `entries[str(index)]`
+3. several CLI/TUI/API paths expect user-facing entry IDs to remain numeric
+
+Shoving reserved `index0` records directly into `entries` would create unnecessary compatibility risk.
+
+So the practical `beta` implementation is:
+
+1. canonical storage inside the same synced payload
+2. separate reserved namespace for system-owned records
+3. optional projection into UI/API later as a virtual view layer
+
+This still satisfies the main requirement: `index0` remains first-class canonical state inside the same encrypted, merged, synced vault.
+
+## 5) What `index0` Must Contain
+
+`index0` should contain three record classes.
+
+### 5.1 `index0_event`
+
+Ground-truth change records.
+
+Purpose:
+
+1. append change history
+2. capture hierarchy and relationship mutations
+3. support audit, sync replay validation, and activity feeds
+
+Minimum fields:
+
+```json
+{
+  "event_id": "sha256(...)",
+  "event_type": "entry_created",
+  "subject_type": "entry",
+  "subject_id": "42",
+  "subject_kind": "document",
+  "scope_path": "seed/<root>/managed/<child>",
+  "actor_type": "user",
+  "actor_id": "<profile fingerprint or agent id>",
+  "writer_id": "<logical writer id>",
+  "modified_ts": 1760000000,
+  "prev_hash": "<optional prior hash in writer stream>",
+  "classification": "internal",
+  "partition": "standard",
+  "policy_ref": "<optional policy stamp or rule id>",
+  "payload_ref": {
+    "entry_id": "42"
+  },
+  "links": [
+    {
+      "target_id": "42",
+      "relation": "describes"
+    }
+  ],
+  "tags": ["kb", "chat", "audit"],
+  "visibility": "private",
+  "integrity_hash": "sha256(...)"
+}
+```
+
+Initial event types:
+
+1. `entry_created`
+2. `entry_modified`
+3. `entry_deleted`
+4. `entry_archived`
+5. `entry_restored`
+6. `link_added`
+7. `link_removed`
+8. `profile_added`
+9. `profile_removed`
+10. `agent_added`
+11. `agent_removed`
+12. `sync_snapshot_published`
+13. `sync_delta_applied`
+14. `nostr_message_indexed`
+15. `document_indexed`
+
+### 5.2 `index0_checkpoint`
+
+Deterministic integrity and compaction anchors.
+
+Purpose:
+
+1. summarize older event windows
+2. cap growth
+3. store checkpoint hashes that manifests can reference
+
+Minimum fields:
+
+```json
+{
+  "checkpoint_id": "cp-000001",
+  "window_start_ts": 1760000000,
+  "window_end_ts": 1760086400,
+  "event_count": 512,
+  "head_hashes": {
+    "writer:<root>": "abc123",
+    "writer:<managed-user>": "def456"
+  },
+  "summary_hash": "sha256(...)",
+  "rollup": {
+    "events_by_type": {
+      "entry_modified": 300,
+      "nostr_message_indexed": 90
+    },
+    "subjects_by_kind": {
+      "document": 120,
+      "note": 90
+    }
+  },
+  "modified_ts": 1760086400
+}
+```
+
+### 5.3 `index0_view`
+
+Derived, regeneratable navigation caches.
+
+Purpose:
+
+1. speed up browsing
+2. avoid recomputing common hierarchy and activity summaries
+3. support future agent navigation and hybrid search routing
+
+Initial views:
+
+1. `children_of:<scope>`
+2. `recent_activity:<scope>`
+3. `top_tags:<scope>`
+4. `counts_by_kind:<scope>`
+5. `hot_nodes:<scope>`
+6. `conversation_index:<scope>`
+
+Views are not the source of truth. They must always be rebuildable from canonical entries plus `index0_event` and `index0_checkpoint`.
+
+### 5.4 Canonical vs local derived views
+
+This is an important design refinement for `beta`.
+
+Do not sync every derived navigation or search view.
+
+Recommended split:
+
+1. `canonical_views`:
+   - low-cardinality, deterministic, cross-device-useful summaries
+   - examples: `children_of`, `counts_by_kind`, compact `recent_activity`
+2. local derived views:
+   - expensive, high-churn, or personalization-oriented caches
+   - examples: semantic neighbor expansions, ranking caches, UI-specific hotlists
+
+Rules:
+
+1. only sync views that materially improve restore/bootstrap/navigation across devices
+2. keep search-heavy and high-cardinality projections local
+3. treat `view_manifest` as the contract for what canonical views exist and how they are versioned
+
+This keeps `index0` useful without recreating a second bloated database inside the vault payload.
+
+## 6) Hash Chaining And Tamper Evidence
+
+For `beta`, use lightweight tamper evidence instead of a full Merkle epoch system.
+
+### 6.1 Event integrity
+
+Each `index0_event` stores:
+
+1. `integrity_hash`: canonical hash of the event payload
+2. `prev_hash`: optional hash of the prior event in the same logical writer stream
+3. `writer_id`: deterministic stream identifier
+
+### 6.2 Why writer streams instead of one global chain
+
+A single global append-only chain is fragile under concurrent multi-device mutation.
+
+The current `beta` branch is already multi-device and delta-merge oriented, so the safer MVP is:
+
+1. hash-chain per logical writer stream
+2. deterministic checkpoint rollups that record the set of stream heads
+3. manifest-level checkpoint metadata for restore validation
+
+This preserves tamper evidence without forcing total ordering across all concurrent writers.
+
+### 6.3 Manifest checkpoint metadata
+
+Extend manifest payloads to optionally include:
+
+```json
+{
+  "index0_checkpoint_id": "cp-000001",
+  "index0_checkpoint_hash": "sha256(...)",
+  "index0_stream_heads": {
+    "writer:<root>": "abc123"
+  }
+}
+```
+
+Validation path on restore:
+
+1. restore latest snapshot
+2. replay newer deltas
+3. recompute current `index0` checkpoint/head material
+4. compare against manifest metadata
+5. raise warning or fail closed based on policy setting
+
+## 7) Deterministic Merge Contract For `index0`
+
+`index0` must not bypass the current merge contract. It should extend it.
+
+Required behavior:
+
+1. base entries still merge with `modified_ts_hash_tombstone_v2`
+2. `_system.index0.events` merges by `event_id`
+3. identical `event_id` payloads are idempotent
+4. equal-subject competing events resolve deterministically using:
+   - `modified_ts`
+   - canonical event hash
+   - tombstone/deletion precedence where applicable
+5. checkpoints and views are regenerated or selected deterministically
+
+Implementation direction:
+
+1. add a dedicated `merge_system_index0(...)` helper beside `merge_index_payloads(...)`
+2. fold its result into the canonical merged payload
+3. keep all timestamps replay-safe and derived from payload data, not wall clock, where merge state is computed
+
+## 8) Deterministic Compaction
+
+`index0` will grow quickly if it tracks chat, docs, and agent activity.
+
+MVP compaction rules:
+
+1. keep recent raw events under a deterministic retention window
+2. roll older events into checkpoints
+3. preserve enough raw events to support recent activity and recent forensic review
+4. preserve checkpoint hashes indefinitely or under a much larger cap
+
+Recommended deterministic policy:
+
+1. retain last `N` raw events per writer stream
+2. retain last `M` days of raw events globally
+3. compact older events into fixed windows:
+   - daily first
+   - weekly later if scale requires
+4. compute checkpoint IDs from canonical window bounds, not device-local counters
+
+Important:
+
+Compaction must be deterministic from payload state alone so two devices compacting the same data converge to the same post-compaction state.
+
+Recommended initial defaults:
+
+1. keep checkpoints indefinitely until an explicit larger cap is required
+2. keep only compact canonical views in sync
+3. rebuild local heavy views on demand after sync or unlock
+
+## 9) Nostr And Communication Scope
+
+The goal is not to make `index0` hold every byte of communication content.
+
+Recommended split:
+
+1. canonical communication artifacts remain normal vault data or future dedicated entry kinds
+2. `index0` records:
+   - existence
+   - ownership/visibility metadata
+   - hierarchy placement
+   - conversation references
+   - recent activity summaries
+3. optional future message/document bodies continue to live in encrypted entries or high-risk partitions
+
+This keeps `index0` useful as a map without turning it into a giant bottleneck payload.
+
+Retention and exposure rules:
+
+1. public Nostr references may be stored as lightweight refs in canonical vault data
+2. private DM content should default to encrypted entry payloads or high-risk partitions, not inline `index0_event` bodies
+3. `index0` should store enough metadata to navigate to a message, not enough to become the message store
+
+## 10) Hierarchy And Permission Model
+
+`index0` must not weaken SeedPass security posture.
+
+Rules:
+
+1. `index0` is encrypted inside the same profile payload as the rest of the vault
+2. `index0` only reveals what the active profile is already authorized to decrypt
+3. manager access to subordinate data should continue to use the existing hierarchy and profile-loading model
+4. future agent access should reuse approval/export/partition controls rather than adding an `index0` bypass
+5. event metadata for high-risk partitions should be minimal and policy-aware
+
+Policy alignment:
+
+1. reuse policy stamps / policy-as-code identifiers where policy-shaped access affects atlas visibility
+2. reuse audit expectations from the agent autonomy plan rather than inventing a second audit vocabulary
+3. keep `classification` and `partition` fields small, deterministic, and non-secret
+
+Institutional knowledge model:
+
+1. each user/agent continues producing canonical artifacts in their scope
+2. `index0` links those artifacts into a searchable atlas
+3. manager-level profiles can build broader navigation views when they already have legitimate access to those scopes
+
+## 11) Interaction With Existing Roadmaps
+
+### 11.1 TUI v2 plan
+
+`index0` is not a prerequisite for the current TUI v2 parity/cutover work.
+
+However, once present it directly improves:
+
+1. real hierarchy navigation
+2. recent activity surfaces
+3. context-aware wayfinding
+4. future conversation and KB sidebars
+
+### 11.2 Semantic index plan
+
+The semantic vector index should remain local-only derived state.
+
+Recommended relationship:
+
+1. `index0` is canonical synced atlas data
+2. semantic vectors remain device-local derived retrieval data
+3. semantic chunking can consume `index0_view` and graph context as ranking features
+
+### 11.3 Entry graph plan
+
+`index0` should reuse `links` conventions instead of inventing a second graph model.
+
+## 12) Implementation Touchpoints In `beta`
+
+Primary files likely to change:
+
+1. `src/seedpass/core/sync_conflict.py`
+   - add deterministic merge support for `_system.index0`
+2. `src/seedpass/core/vault.py`
+   - load/save/migration handling for `_system.index0`
+3. `src/seedpass/core/encryption.py`
+   - merge path for restored payloads
+4. `src/nostr/backup_models.py`
+   - manifest metadata extension for `index0` checkpoint fields
+5. `src/nostr/snapshot.py`
+   - publish/fetch manifest support for `index0` checkpoint metadata
+6. `src/seedpass/core/entry_management.py`
+   - emit `index0_event` records on create/update/delete/link actions
+7. `src/seedpass/core/api.py`
+   - expose atlas inspection/status endpoints
+8. `src/seedpass/core/semantic_index.py`
+   - optional future use of `index0_view` context during hybrid retrieval
+9. `src/seedpass/core/state_manager.py`
+   - only if local rebuild or validation state must be persisted
+10. `src/seedpass/core/agent_export_policy.py`
+   - if atlas reads need policy-shaped export or redaction behavior
+
+## 13) Delivery Phases
+
+## Phase 0: Spec And Schema Lock
+
+Deliver:
+
+1. finalize `_system.index0` payload shape
+2. finalize event/checkpoint/view schemas
+3. define manifest extension fields
+4. define deterministic compaction contract
+
+Exit criteria:
+
+1. schema doc merged
+2. migration strategy documented
+3. no open ambiguity on user-entry ID compatibility
+
+## Phase 1: Canonical Storage + Merge
+
+Deliver:
+
+1. payload migrations for `_system.index0`
+2. `merge_system_index0(...)`
+3. event ID and integrity hash helpers
+4. deterministic checkpoint selection rules
+
+Exit criteria:
+
+1. replay idempotency holds
+2. stale payloads cannot override newer `index0` state
+3. merge order independence proven by tests
+
+## Phase 2: Event Emission Hooks
+
+Deliver:
+
+1. emit events on entry CRUD
+2. emit events on archive/restore
+3. emit events on link add/remove
+4. emit events on profile/agent lifecycle operations where already represented in core flows
+
+Exit criteria:
+
+1. user-visible mutations update `index0` automatically
+2. no manual rebuild required for core audit path
+
+## Phase 3: Manifest Checkpoints + Validation
+
+Deliver:
+
+1. extend manifest schema
+2. write checkpoint metadata during snapshot publish
+3. validate checkpoint/head metadata during restore
+4. define warning vs hard-fail policy
+
+Exit criteria:
+
+1. snapshot/delta replay can verify `index0` checkpoint continuity
+2. failure states are explicit and test-covered
+
+## Phase 4: Deterministic Compaction
+
+Deliver:
+
+1. raw-event retention windows
+2. checkpoint rollup generation
+3. deterministic pruning
+4. migration path for older payloads without checkpoints
+
+Exit criteria:
+
+1. event growth remains bounded
+2. two devices compacting the same payload converge
+
+## Phase 5: Read APIs And Wayfinder Views
+
+Deliver:
+
+1. atlas status API/CLI surface
+2. recent activity feed
+3. children-of and counts-by-kind views
+4. hot-nodes and top-tags views
+
+Exit criteria:
+
+1. user/agent can navigate from atlas state without scanning the full vault
+2. views can be rebuilt from canonical data
+
+## Phase 6: Communication And KB Integration
+
+Deliver:
+
+1. add event hooks for future Nostr chat/document workflows
+2. add message/conversation references
+3. integrate atlas cues into KB and semantic search experiences
+4. keep raw private communication content out of canonical atlas events
+
+Exit criteria:
+
+1. institutional knowledge use cases work without changing cryptographic source-of-truth rules
+
+## 14) Testing Plan
+
+Required new tests:
+
+1. unit:
+   - event hash generation
+   - writer-stream hash chaining
+   - checkpoint hash generation
+   - deterministic compaction selection
+2. merge:
+   - order independence
+   - replay idempotency
+   - stale event rejection
+   - concurrent writer-stream head preservation
+3. migration:
+   - old payload without `_system.index0` upgrades cleanly
+   - namespace reset still works
+4. Nostr sync:
+   - manifest metadata round-trip
+   - snapshot + delta restore validation
+   - checkpoint mismatch handling
+5. integration:
+   - CRUD emits events
+   - link operations emit events
+   - archive/delete semantics converge
+6. scale:
+   - large KB/chat event volume
+   - compaction boundedness
+
+Likely test homes:
+
+1. `src/tests/test_delta_merge.py`
+2. new `src/tests/test_index0_merge.py`
+3. new `src/tests/test_index0_compaction.py`
+4. new `src/tests/test_index0_manifest_validation.py`
+5. targeted API/CLI/TUI tests once read surfaces exist
+
+## 15) Sequencing Against The Current Dev Plan
+
+Recommended sequencing in `beta`:
+
+1. now:
+   - Phase 0 spec and schema lock
+   - no conflict with current TUI work
+2. after current cutover-critical TUI/security slices are stable:
+   - Phases 1 through 3
+3. after semantic hybrid hardening resumes:
+   - Phase 5 atlas read surfaces and semantic interplay
+4. after communication entry types or Nostr DM indexing lands:
+   - Phase 6
+
+Practical interpretation:
+
+1. start the architecture/spec work immediately
+2. do not let `index0` disrupt TUI parity closeout or current security readiness gates
+3. implement core atlas plumbing as the next major core-data track once current cutover work is no longer the top release blocker
+
+## 16) Open Design Questions
+
+These should be resolved in Phase 0 before code lands:
+
+1. should `writer_id` be profile-fingerprint based, device based, or actor based?
+2. should checkpoint mismatch fail restore or warn and continue by default?
+3. which communication payloads are canonical vault entries versus external references?
+4. should manager-level aggregate atlas views be materialized or computed on demand?
+5. should `writer_id` default to profile scope first and only later split by agent identity where needed?
+
+## 17) Bottom Line
+
+For the current `beta` branch, the right implementation is:
+
+1. keep `index0` inside the existing encrypted snapshot/delta payload
+2. model it as a reserved `_system.index0` atlas namespace
+3. use lightweight hash-chained writer streams plus manifest checkpoint hashes
+4. compact deterministically
+5. expose fast navigation through rebuildable views
+
+This gives SeedPass a canonical launch pad and map for institutional knowledge without abandoning the sync, determinism, and hierarchy model that `beta` already has.
diff --git a/docs/index0_phase0_spec_2026-03-05.md b/docs/index0_phase0_spec_2026-03-05.md
new file mode 100644
index 00000000..2e3ade42
--- /dev/null
+++ b/docs/index0_phase0_spec_2026-03-05.md
@@ -0,0 +1,620 @@
+# Index0 Phase 0 Implementation Spec (2026-03-05)
+
+Status: Proposed  
+Branch target: `beta`  
+Depends on: `docs/index0_atlas_execution_plan_2026-03-05.md`
+
+## 1) Goal
+
+Lock the Phase 0 implementation contract for `index0` so coding can begin without schema drift.
+
+This document defines:
+
+1. canonical payload schema
+2. manifest extension fields
+3. normalization and hashing rules
+4. deterministic merge rules
+5. deterministic compaction defaults
+6. first implementation slice
+7. first test matrix
+
+## 2) Canonical Payload Contract
+
+`index0` lives inside the same encrypted vault payload in a reserved namespace:
+
+```json
+{
+  "schema_version": 3,
+  "entries": {},
+  "_sync_meta": {},
+  "_system": {
+    "index0": {
+      "schema_version": 1,
+      "events": {},
+      "checkpoints": {},
+      "canonical_views": {},
+      "view_manifest": {},
+      "heads": {},
+      "stats": {}
+    }
+  }
+}
+```
+
+Normalization requirements:
+
+1. missing `_system` must be treated as `{}`
+2. missing `_system.index0` must be initialized during load or merge
+3. all `events`, `checkpoints`, `canonical_views`, `heads`, and `stats` members must be JSON objects
+4. all keys must be ASCII strings
+5. the canonical JSON hash function must use `sort_keys=True` and compact separators `(",", ":")`
+
+## 3) Schema Definitions
+
+### 3.1 `index0_event`
+
+Storage key:
+
+- `events[event_id]`
+
+Required fields:
+
+```json
+{
+  "event_id": "e:sha256hex",
+  "event_type": "entry_created",
+  "subject_type": "entry",
+  "subject_id": "42",
+  "subject_kind": "document",
+  "scope_path": "seed/<root>/managed/<child>",
+  "actor_type": "user",
+  "actor_id": "<profile fingerprint or agent id>",
+  "writer_id": "writer:<scope-or-profile>",
+  "modified_ts": 1760000000,
+  "prev_hash": "",
+  "classification": "internal",
+  "partition": "standard",
+  "payload_ref": {
+    "entry_id": "42"
+  },
+  "links": [],
+  "tags": [],
+  "visibility": "private",
+  "integrity_hash": "sha256hex"
+}
+```
+
+Optional fields:
+
+```json
+{
+  "policy_ref": "<policy stamp or stable rule id>",
+  "source": "entry_management",
+  "source_event_id": "<nostr event id or external ref>",
+  "summary": "<short safe summary>"
+}
+```
+
+Enum constraints:
+
+1. `event_type`:
+   - `entry_created`
+   - `entry_modified`
+   - `entry_deleted`
+   - `entry_archived`
+   - `entry_restored`
+   - `link_added`
+   - `link_removed`
+   - `profile_added`
+   - `profile_removed`
+   - `agent_added`
+   - `agent_removed`
+   - `sync_snapshot_published`
+   - `sync_delta_applied`
+   - `nostr_message_indexed`
+   - `document_indexed`
+2. `subject_type`:
+   - `entry`
+   - `profile`
+   - `agent`
+   - `conversation`
+   - `document`
+   - `sync`
+3. `actor_type`:
+   - `user`
+   - `agent`
+   - `system`
+4. `classification`:
+   - `public`
+   - `internal`
+   - `restricted`
+   - `secret`
+5. `partition`:
+   - `standard`
+   - `high_risk`
+6. `visibility`:
+   - `public`
+   - `private`
+   - `policy_scoped`
+
+Normalization rules:
+
+1. `event_id`, `subject_id`, `actor_id`, and `writer_id` are stored as strings
+2. `modified_ts` must be an integer greater than zero
+3. `prev_hash` defaults to `""`
+4. `links` must use the same canonical link normalization rules already used for entries
+5. `tags` must be unique and lexicographically sorted
+6. `summary` must never contain secret material
+7. `integrity_hash` is computed from the canonical event body excluding the `integrity_hash` field itself
+
+### 3.2 `index0_checkpoint`
+
+Storage key:
+
+- `checkpoints[checkpoint_id]`
+
+Required fields:
+
+```json
+{
+  "checkpoint_id": "cp:day:2026-03-05:writer:<root>",
+  "window_type": "day",
+  "window_key": "2026-03-05",
+  "writer_id": "writer:<root>",
+  "window_start_ts": 1760000000,
+  "window_end_ts": 1760086399,
+  "event_count": 512,
+  "head_hash": "sha256hex",
+  "summary_hash": "sha256hex",
+  "rollup": {
+    "events_by_type": {},
+    "subjects_by_kind": {},
+    "subjects": []
+  },
+  "modified_ts": 1760086399
+}
+```
+
+Normalization rules:
+
+1. initial implementation supports only `window_type = "day"`
+2. `checkpoint_id` must be deterministic from `window_type`, `window_key`, and `writer_id`
+3. `subjects` must be a sorted unique list and capped deterministically
+4. `summary_hash` is computed from the canonical checkpoint body excluding `summary_hash`
+
+### 3.3 `canonical_view`
+
+Storage key:
+
+- `canonical_views[view_id]`
+
+Required fields:
+
+```json
+{
+  "view_id": "children_of:seed/<root>",
+  "view_type": "children_of",
+  "scope_path": "seed/<root>",
+  "source_checkpoint_ids": [],
+  "source_event_ids": [],
+  "data": {},
+  "modified_ts": 1760086400,
+  "view_hash": "sha256hex"
+}
+```
+
+Normalization rules:
+
+1. only compact low-cardinality views are eligible for canonical sync in Phase 1
+2. `data` must be deterministic and sorted by stable keys
+3. `view_hash` is computed from the canonical view body excluding `view_hash`
+
+### 3.4 `view_manifest`
+
+Purpose:
+
+1. declare canonical synced views
+2. version view builders
+3. make local rebuild policy explicit
+
+Schema:
+
+```json
+{
+  "version": 1,
+  "canonical_view_types": [
+    "children_of",
+    "counts_by_kind",
+    "recent_activity"
+  ],
+  "local_only_view_types": [
+    "hot_nodes",
+    "conversation_index",
+    "semantic_neighbors"
+  ],
+  "builder_versions": {
+    "children_of": 1,
+    "counts_by_kind": 1,
+    "recent_activity": 1
+  }
+}
+```
+
+### 3.5 `heads`
+
+Purpose:
+
+Track current writer-stream head hashes.
+
+Schema:
+
+```json
+{
+  "writer:<root>": {
+    "event_id": "e:sha256hex",
+    "head_hash": "sha256hex",
+    "modified_ts": 1760086400
+  }
+}
+```
+
+Rules:
+
+1. each `writer_id` has at most one head record
+2. higher `modified_ts` wins
+3. equal timestamp resolves by lexicographically larger `head_hash`
+
+### 3.6 `stats`
+
+Initial synced stats:
+
+```json
+{
+  "event_count": 1280,
+  "checkpoint_count": 14,
+  "writer_count": 3,
+  "last_compaction_ts": 1760086400,
+  "last_validation_ts": 1760086400
+}
+```
+
+Stats are advisory and deterministically derived. They are never the source of truth.
+
+## 4) Manifest Extension Contract
+
+The current manifest already carries snapshot metadata. Extend it with optional `index0` fields:
+
+```json
+{
+  "ver": 1,
+  "algo": "gzip",
+  "chunks": [],
+  "delta_since": 1760086400,
+  "nonce": "base64...",
+  "index0": {
+    "schema_version": 1,
+    "checkpoint_ids": [
+      "cp:day:2026-03-05:writer:<root>"
+    ],
+    "checkpoint_hashes": {
+      "cp:day:2026-03-05:writer:<root>": "sha256hex"
+    },
+    "stream_heads": {
+      "writer:<root>": "sha256hex"
+    }
+  }
+}
+```
+
+Manifest rules:
+
+1. manifest `index0` section is optional for backward compatibility
+2. restore must accept manifests with no `index0`
+3. manifest `index0` metadata is validation material, not source-of-truth state
+4. if present, it must be recomputable from the decrypted payload after replay
+
+## 5) Hashing And ID Rules
+
+### 5.1 Canonical helper
+
+Use the same canonical JSON discipline already used by the sync layer:
+
+```python
+json.dumps(value, sort_keys=True, separators=(",", ":"))
+```
+
+### 5.2 Event body hash
+
+Pseudo:
+
+```python
+def canonical_event_body(event):
+    body = dict(event)
+    body.pop("integrity_hash", None)
+    return body
+
+def compute_event_hash(event):
+    return sha256(canonical(canonical_event_body(event)))
+```
+
+### 5.3 Event ID
+
+For Phase 1, event IDs should be content-addressed and deterministic:
+
+```python
+event_id = "e:" + compute_event_hash(event)
+```
+
+This intentionally makes duplicate event publication idempotent.
+
+### 5.4 Head hash
+
+Pseudo:
+
+```python
+def compute_head_hash(event):
+    marker = {
+        "event_id": event["event_id"],
+        "integrity_hash": event["integrity_hash"],
+        "prev_hash": event.get("prev_hash", ""),
+        "writer_id": event["writer_id"],
+    }
+    return sha256(canonical(marker))
+```
+
+### 5.5 Checkpoint ID
+
+Pseudo:
+
+```python
+checkpoint_id = f"cp:day:{window_key}:{writer_id}"
+```
+
+### 5.6 Checkpoint hash
+
+Pseudo:
+
+```python
+def compute_checkpoint_hash(checkpoint):
+    body = dict(checkpoint)
+    body.pop("summary_hash", None)
+    return sha256(canonical(body))
+```
+
+## 6) Writer Model
+
+Phase 1 writer rule:
+
+1. `writer_id` defaults to profile scope, not device instance
+2. format:
+   - root profile: `writer:profile:<fingerprint>`
+   - managed scope: `writer:profile:<fingerprint>:managed:<subject>`
+   - agent scope later if needed: `writer:agent:<agent_id>`
+
+Rationale:
+
+1. profile-scoped writers are simpler and stable across devices
+2. this fits current `beta` multi-device deterministic merge better than device-scoped streams
+3. agent-specific streams can be added later without invalidating the contract
+
+## 7) Deterministic Merge Rules
+
+`merge_index_payloads(...)` remains the top-level orchestrator.
+
+Add:
+
+```python
+merge_system_index0(current_index0, incoming_index0) -> merged_index0
+```
+
+### 7.1 Event merge
+
+Rules:
+
+1. merge by `event_id`
+2. if only one side contains an event, keep it
+3. if both sides contain the same `event_id` and canonical bodies match, keep one
+4. if both sides contain the same `event_id` but bodies differ, pick the event with lexicographically larger canonical body hash and record a validation warning path later
+
+This last case should be treated as corruption-suspicious and covered by tests even if it should not occur in normal generation.
+
+### 7.2 Head merge
+
+Rules:
+
+1. merge by `writer_id`
+2. higher `modified_ts` wins
+3. equal timestamp resolves by larger `head_hash`
+
+### 7.3 Checkpoint merge
+
+Rules:
+
+1. merge by `checkpoint_id`
+2. if both sides contain the same `checkpoint_id` with different bodies, select lexicographically larger `summary_hash`
+3. equal bodies remain idempotent
+
+### 7.4 Canonical view merge
+
+Rules:
+
+1. merge by `view_id`
+2. higher `modified_ts` wins
+3. equal timestamp resolves by larger `view_hash`
+4. local-only views must never be written into canonical synced payload
+
+### 7.5 Stats merge
+
+Rules:
+
+1. stats are recomputed from merged payload where practical
+2. if not recomputed, use deterministic max/union semantics only
+
+## 8) Merge Pseudocode
+
+```python
+def merge_system_index0(current, incoming):
+    cur = normalize_index0(current)
+    inc = normalize_index0(incoming)
+
+    merged_events = merge_events(cur["events"], inc["events"])
+    merged_heads = merge_heads(cur["heads"], inc["heads"])
+    merged_checkpoints = merge_checkpoints(
+        cur["checkpoints"], inc["checkpoints"]
+    )
+    merged_views = merge_canonical_views(
+        cur["canonical_views"], inc["canonical_views"], cur["view_manifest"], inc["view_manifest"]
+    )
+    merged_view_manifest = merge_view_manifest(
+        cur["view_manifest"], inc["view_manifest"]
+    )
+
+    merged = {
+        "schema_version": max(cur["schema_version"], inc["schema_version"]),
+        "events": merged_events,
+        "checkpoints": merged_checkpoints,
+        "canonical_views": merged_views,
+        "view_manifest": merged_view_manifest,
+        "heads": merged_heads,
+        "stats": recompute_stats(
+            merged_events, merged_checkpoints, merged_heads
+        ),
+    }
+    return compact_index0(merged)
+```
+
+## 9) Deterministic Compaction Defaults
+
+Phase 1 compaction must stay intentionally simple.
+
+Defaults:
+
+1. raw event retention per writer:
+   - keep last `512` raw events
+2. raw event retention by age:
+   - keep last `30` days
+3. checkpoint window:
+   - daily
+4. canonical view retention:
+   - keep only latest view per `view_id`
+5. checkpoint subject list cap:
+   - `128`
+
+Compaction order:
+
+1. group events by `writer_id`
+2. within each writer, sort by:
+   - `modified_ts`
+   - `event_id`
+3. materialize daily checkpoints for prunable windows
+4. prune raw events only after checkpoint exists
+5. recompute heads and stats
+
+Guarantee:
+
+If two devices compact the same normalized payload, they must produce the same payload.
+
+## 10) Initial Builder Scope
+
+The first code slice should not try to solve the full knowledge-base product.
+
+Phase 1 implementation should include only:
+
+1. `_system.index0` schema initialization and migration
+2. event emission for:
+   - entry create
+   - entry modify
+   - entry delete
+   - entry archive
+   - entry restore
+   - link add
+   - link remove
+3. merge support
+4. head maintenance
+5. manifest `index0` metadata round-trip
+
+Deferred until later phases:
+
+1. communication-specific event emission
+2. local rebuild daemons
+3. UI-facing atlas panels
+4. semantic interplay
+5. policy-filtered atlas export
+
+## 11) Failure Handling
+
+Rules:
+
+1. malformed `index0` objects must normalize to empty structures where safe
+2. malformed individual events/checkpoints/views should be dropped during normalization if required fields are invalid
+3. manifest `index0` mismatches should warn by default in the first implementation
+4. hard-fail behavior can be added later behind policy/config
+
+## 12) Test Matrix
+
+### 12.1 Unit
+
+1. `normalize_index0` fills defaults and drops malformed objects
+2. `compute_event_hash` is stable
+3. `compute_head_hash` is stable
+4. `compute_checkpoint_hash` is stable
+5. tag normalization is deterministic
+6. checkpoint ID generation is deterministic
+
+### 12.2 Merge
+
+1. event merge is idempotent
+2. event merge is order independent
+3. conflicting same-`event_id` bodies resolve deterministically
+4. head merge prefers newer `modified_ts`
+5. equal timestamp head merge prefers larger `head_hash`
+6. view merge rejects local-only view types in canonical payload
+
+### 12.3 Replay / vault boundary
+
+1. payload with `_system.index0` survives encrypt/decrypt round-trip
+2. repeated merge through vault boundary is idempotent
+3. stale payload replay cannot remove newer heads/checkpoints
+
+### 12.4 Migration
+
+1. old payload without `_system` upgrades cleanly
+2. old payload with malformed `_system.index0` repairs cleanly
+3. existing entry CRUD remains unchanged
+
+### 12.5 Nostr manifest
+
+1. manifest serializes and parses optional `index0`
+2. restore accepts legacy manifest with no `index0`
+3. restore warning path triggers on checkpoint/head mismatch
+
+### 12.6 Integration
+
+1. add entry emits `entry_created`
+2. modify entry emits `entry_modified`
+3. delete path emits `entry_deleted`
+4. archive/restore emit expected events
+5. link add/remove emit expected events
+
+## 13) Implementation Order
+
+Recommended coding order:
+
+1. add normalization + hashing helpers in a new `index0` module
+2. extend merge logic with `merge_system_index0`
+3. extend manifest dataclass and serializer/parser
+4. add payload migration/init in vault load path
+5. emit events from entry-management hooks
+6. add tests in lockstep
+
+## 14) Definition Of Phase 0 Complete
+
+Phase 0 is complete when:
+
+1. this schema contract is accepted
+2. manifest extension fields are accepted
+3. merge and compaction rules are accepted
+4. first implementation slice is accepted
+5. test inventory is accepted
+
+At that point, implementation can move directly into Phase 1 without reopening architecture questions.
diff --git a/src/nostr/backup_models.py b/src/nostr/backup_models.py
index 7918c5c1..860c1bc7 100644
--- a/src/nostr/backup_models.py
+++ b/src/nostr/backup_models.py
@@ -1,5 +1,5 @@
 from dataclasses import dataclass
-from typing import List, Optional
+from typing import Any, List, Optional
 
 # Event kind constants used for SeedPass backups
 KIND_MANIFEST = 30070
@@ -26,3 +26,4 @@ class Manifest:
     chunks: List[ChunkMeta]
     delta_since: Optional[int] = None
     nonce: Optional[str] = None
+    index0: Optional[dict[str, Any]] = None
diff --git a/src/nostr/snapshot.py b/src/nostr/snapshot.py
index 1d4858eb..2a238f5b 100644
--- a/src/nostr/snapshot.py
+++ b/src/nostr/snapshot.py
@@ -114,6 +114,7 @@ class SnapshotHandler:
                 "chunks": [meta.__dict__ for meta in manifest.chunks],
                 "delta_since": manifest.delta_since,
                 "nonce": manifest.nonce,
+                "index0": manifest.index0,
             }
         )
 
@@ -151,6 +152,9 @@ class SnapshotHandler:
                     else None
                 ),
                 nonce=data.get("nonce"),
+                index0=(
+                    data.get("index0") if isinstance(data.get("index0"), dict) else None
+                ),
             )
         except Exception:
             return None
@@ -376,6 +380,7 @@ class SnapshotHandler:
                         ],
                         "delta_since": self.current_manifest.delta_since,
                         "nonce": self.current_manifest.nonce,
+                        "index0": self.current_manifest.index0,
                     }
                 )
                 manifest_event = (
diff --git a/src/seedpass/cli/__init__.py b/src/seedpass/cli/__init__.py
index 6cc2ea3c..efbd3003 100644
--- a/src/seedpass/cli/__init__.py
+++ b/src/seedpass/cli/__init__.py
@@ -14,7 +14,7 @@ from .common import _get_entry_service, _get_services
 from seedpass.core.errors import SeedPassError
 from constants import GUI_BACKEND_CONFIG
 from seedpass.tui_v2.app import check_tui2_runtime, launch_tui2
-from seedpass.tui_v3 import launch_tui3
+from seedpass.tui_v3 import check_tui3_runtime, launch_tui3
 
 app = typer.Typer(
     help=(
@@ -49,11 +49,11 @@ deterministic_totp_option = typer.Option(
 legacy_tui_option = typer.Option(
     False,
     "--legacy-tui",
-    help="Use legacy interactive TUI (temporary fallback during TUI v2 cutover)",
+    help="Use legacy interactive TUI explicitly",
 )
 
 tui_version_option = typer.Option(
-    "v2",
+    "v3",
     "--tui",
     help="Select TUI version: legacy, v2, v3",
 )
@@ -154,6 +154,36 @@ def _launch_legacy_tui(*, fingerprint: Optional[str]) -> typer.Exit:
         return typer.Exit(legacy_main(fingerprint=fingerprint))
 
 
+def _launch_tui3_or_exit(
+    *,
+    fingerprint: Optional[str],
+    services: Optional[dict[str, object]] = None,
+) -> None:
+    kwargs: dict[str, object] = {"fingerprint": fingerprint}
+    if services is not None:
+        kwargs.update(
+            {
+                "entry_service_factory": lambda: services["entry"],
+                "profile_service_factory": lambda: services["profile"],
+                "config_service_factory": lambda: services["config"],
+                "nostr_service_factory": lambda: services["nostr"],
+                "sync_service_factory": lambda: services["sync"],
+                "utility_service_factory": lambda: services["utility"],
+                "vault_service_factory": lambda: services["vault"],
+                "semantic_service_factory": lambda: services["semantic"],
+            }
+        )
+    launched = launch_tui3(**kwargs)
+    if launched:
+        return
+    typer.echo(
+        "TUI v3 runtime unavailable. Run `seedpass tui3 --check` for diagnostics, "
+        "`seedpass tui2` to launch TUI v2, or `seedpass legacy` for the legacy interface.",
+        err=True,
+    )
+    raise typer.Exit(1)
+
+
 @app.callback(invoke_without_command=True)
 def main(
     ctx: typer.Context,
@@ -188,27 +218,17 @@ def main(
         if legacy_tui or tui_version == "legacy":
             raise _launch_legacy_tui(fingerprint=fingerprint)
 
+        if tui_version == "v3":
+            _launch_tui3_or_exit(fingerprint=fingerprint)
+            return
+
         services, preflight_error = _prime_tui2_service(ctx)
         if preflight_error is not None:
             typer.echo(
-                f"TUI {tui_version} preflight failed; falling back to legacy TUI. "
-                f"Details: {preflight_error}"
+                f"TUI {tui_version} preflight failed: {preflight_error}",
+                err=True,
             )
-            raise _launch_legacy_tui(fingerprint=fingerprint)
-
-        if tui_version == "v3":
-            launch_tui3(
-                fingerprint=fingerprint,
-                entry_service_factory=lambda: services["entry"],
-                profile_service_factory=lambda: services["profile"],
-                config_service_factory=lambda: services["config"],
-                nostr_service_factory=lambda: services["nostr"],
-                sync_service_factory=lambda: services["sync"],
-                utility_service_factory=lambda: services["utility"],
-                vault_service_factory=lambda: services["vault"],
-                semantic_service_factory=lambda: services["semantic"],
-            )
-            return
+            raise typer.Exit(1)
 
         launched = launch_tui2(
             fingerprint=fingerprint,
@@ -225,10 +245,10 @@ def main(
             return
 
         typer.echo(
-            f"TUI {tui_version} runtime unavailable; falling back to legacy TUI. "
-            "Run `seedpass tui2 --check` for diagnostics."
+            "TUI v2 runtime unavailable. Run `seedpass tui2 --check` for diagnostics, "
+            "or use `seedpass legacy` for the legacy interface."
         )
-        raise _launch_legacy_tui(fingerprint=fingerprint)
+        raise typer.Exit(1)
 
 
 @app.command("lock")
@@ -310,30 +330,13 @@ def tui3(
         help="Check whether TUI v3 runtime dependencies are available",
     ),
 ) -> None:
-    """Launch the experimental TUI v3 scratch architecture."""
+    """Launch the current TUI v3 interface."""
     if check:
-        from seedpass.tui_v3 import check_tui3_runtime
-
         typer.echo(json.dumps(check_tui3_runtime(), indent=2, sort_keys=True))
         return
 
     fingerprint = (ctx.obj or {}).get("fingerprint")
-    services, preflight_error = _prime_tui2_service(ctx)
-    if preflight_error is not None:
-        typer.echo(f"TUI v3 preflight failed: {preflight_error}", err=True)
-        raise typer.Exit(1)
-
-    launch_tui3(
-        fingerprint=fingerprint,
-        entry_service_factory=lambda: services["entry"],
-        profile_service_factory=lambda: services["profile"],
-        config_service_factory=lambda: services["config"],
-        nostr_service_factory=lambda: services["nostr"],
-        sync_service_factory=lambda: services["sync"],
-        utility_service_factory=lambda: services["utility"],
-        vault_service_factory=lambda: services["vault"],
-        semantic_service_factory=lambda: services["semantic"],
-    )
+    _launch_tui3_or_exit(fingerprint=fingerprint)
 
 
 @app.command("legacy")
diff --git a/src/seedpass/cli/capabilities.py b/src/seedpass/cli/capabilities.py
index fedba3d4..20e3ccb6 100644
--- a/src/seedpass/cli/capabilities.py
+++ b/src/seedpass/cli/capabilities.py
@@ -14,11 +14,12 @@ def build_capabilities() -> dict[str, Any]:
         "product": "SeedPass",
         "interfaces": {
             "cli": {
+                "default_interface": "tui3",
                 "root_commands": [
                     "lock",
                     "gui",
-                    "tui2",
                     "tui3",
+                    "tui2",
                     "legacy",
                     "capabilities",
                     "entry",
@@ -266,8 +267,9 @@ def build_capabilities() -> dict[str, Any]:
             "Run `seedpass --help` for top-level commands.",
             "Run `seedpass <group> --help` for detailed options.",
             "Use `seedpass capabilities --format json` for machine-readable discovery.",
-            "Run `seedpass tui2 --check` before adopting Textual-based TUI v2.",
-            "Use `seedpass --legacy-tui` to force the legacy interface during cutover.",
+            "Run `seedpass` or `seedpass tui3` to launch the current TUI v3.",
+            "Run `seedpass tui2 --check` before using the maintained-but-non-default TUI v2.",
+            "Use `seedpass legacy` or `seedpass --legacy-tui` for the legacy interface.",
             "In TUI v2, use `?` for help, `j` to jump to entry id, `1/2/3` to focus panes, `Ctrl+P` for palette, `p/n` for paging, and `x` to retry.",
             "For graph workflows, start with `seedpass entry link-add --help` and `seedpass entry links --help`.",
             "For semantic KB retrieval, run `seedpass semantic --help` and check `seedpass semantic status`.",
diff --git a/src/seedpass/core/encryption.py b/src/seedpass/core/encryption.py
index 07ba0405..0e825580 100644
--- a/src/seedpass/core/encryption.py
+++ b/src/seedpass/core/encryption.py
@@ -29,6 +29,7 @@ from mnemonic import Mnemonic
 from utils.password_prompt import prompt_existing_password
 from utils.key_derivation import KdfConfig, CURRENT_KDF_VERSION
 from .errors import DecryptionError
+from .index0 import ensure_index0_payload
 from .sync_conflict import merge_index_payloads
 
 # Instantiate the logger
@@ -479,6 +480,7 @@ class EncryptionManager:
                 data = json_lib.loads(decrypted)
             else:
                 data = json_lib.loads(decrypted.decode("utf-8"))
+            data = ensure_index0_payload(data)
             existing_file = self.resolve_relative_path(relative_path)
             if merge and existing_file.exists():
                 current = self.load_json_data(relative_path)
diff --git a/src/seedpass/core/index0.py b/src/seedpass/core/index0.py
new file mode 100644
index 00000000..d7907f50
--- /dev/null
+++ b/src/seedpass/core/index0.py
@@ -0,0 +1,437 @@
+from __future__ import annotations
+
+import hashlib
+import json
+from typing import Any
+
+INDEX0_SCHEMA_VERSION = 1
+LOCAL_ONLY_VIEW_TYPES = {"hot_nodes", "conversation_index", "semantic_neighbors"}
+
+
+def _canonical(value: Any) -> str:
+    return json.dumps(value, sort_keys=True, separators=(",", ":"))
+
+
+def _sha256_hex(value: Any) -> str:
+    if isinstance(value, str):
+        payload = value.encode("utf-8")
+    else:
+        payload = _canonical(value).encode("utf-8")
+    return hashlib.sha256(payload).hexdigest()
+
+
+def _normalize_string(value: Any) -> str:
+    return str(value).strip()
+
+
+def _safe_int(raw: Any, *, default: int = 0) -> int:
+    try:
+        return int(raw)
+    except Exception:
+        return int(default)
+
+
+def _normalize_tags(raw_tags: Any) -> list[str]:
+    if not isinstance(raw_tags, list):
+        return []
+    out = sorted({_normalize_string(tag) for tag in raw_tags if _normalize_string(tag)})
+    return out
+
+
+def _normalize_links(raw_links: Any) -> list[dict[str, Any]]:
+    if not isinstance(raw_links, list):
+        return []
+    out: dict[str, dict[str, Any]] = {}
+    for item in raw_links:
+        if not isinstance(item, dict):
+            continue
+        target_id = _normalize_string(item.get("target_id", ""))
+        relation = _normalize_string(item.get("relation", ""))
+        note = _normalize_string(item.get("note", ""))
+        if not target_id or not relation:
+            continue
+        normalized = {"target_id": target_id, "relation": relation}
+        if note:
+            normalized["note"] = note
+        out[_canonical(normalized)] = normalized
+    return [out[key] for key in sorted(out.keys())]
+
+
+def _normalize_mapping(raw: Any) -> dict[str, Any]:
+    return dict(raw) if isinstance(raw, dict) else {}
+
+
+def normalize_index0(raw: Any) -> dict[str, Any]:
+    data = dict(raw) if isinstance(raw, dict) else {}
+    normalized = {
+        "schema_version": max(
+            INDEX0_SCHEMA_VERSION,
+            _safe_int(data.get("schema_version", INDEX0_SCHEMA_VERSION), default=1),
+        ),
+        "events": {},
+        "checkpoints": {},
+        "canonical_views": {},
+        "view_manifest": {},
+        "heads": {},
+        "stats": {},
+    }
+    for event_id, event in _normalize_mapping(data.get("events")).items():
+        normalized_event = normalize_index0_event(event)
+        if normalized_event is None:
+            continue
+        normalized["events"][str(event_id)] = normalized_event
+    for checkpoint_id, checkpoint in _normalize_mapping(
+        data.get("checkpoints")
+    ).items():
+        normalized_checkpoint = normalize_index0_checkpoint(checkpoint)
+        if normalized_checkpoint is None:
+            continue
+        normalized["checkpoints"][str(checkpoint_id)] = normalized_checkpoint
+    view_manifest = normalize_view_manifest(data.get("view_manifest"))
+    normalized["view_manifest"] = view_manifest
+    for view_id, view in _normalize_mapping(data.get("canonical_views")).items():
+        normalized_view = normalize_canonical_view(view, view_manifest=view_manifest)
+        if normalized_view is None:
+            continue
+        normalized["canonical_views"][str(view_id)] = normalized_view
+    for writer_id, head in _normalize_mapping(data.get("heads")).items():
+        normalized_head = normalize_head(head)
+        if normalized_head is None:
+            continue
+        normalized["heads"][str(writer_id)] = normalized_head
+    normalized["stats"] = recompute_index0_stats(normalized)
+    return normalized
+
+
+def ensure_index0_payload(data: dict[str, Any]) -> dict[str, Any]:
+    out = dict(data) if isinstance(data, dict) else {}
+    system = dict(out.get("_system")) if isinstance(out.get("_system"), dict) else {}
+    system["index0"] = normalize_index0(system.get("index0"))
+    out["_system"] = system
+    return out
+
+
+def normalize_view_manifest(raw: Any) -> dict[str, Any]:
+    data = dict(raw) if isinstance(raw, dict) else {}
+    canonical_view_types = sorted(
+        {
+            _normalize_string(item)
+            for item in data.get("canonical_view_types", [])
+            if _normalize_string(item)
+        }
+    )
+    local_only_view_types = sorted(
+        {
+            _normalize_string(item)
+            for item in data.get("local_only_view_types", [])
+            if _normalize_string(item)
+        }
+    )
+    builder_versions = {}
+    raw_versions = data.get("builder_versions", {})
+    if isinstance(raw_versions, dict):
+        for key, value in raw_versions.items():
+            key_str = _normalize_string(key)
+            if not key_str:
+                continue
+            builder_versions[key_str] = _safe_int(value, default=1)
+    return {
+        "version": max(1, _safe_int(data.get("version", 1), default=1)),
+        "canonical_view_types": canonical_view_types,
+        "local_only_view_types": local_only_view_types,
+        "builder_versions": dict(sorted(builder_versions.items())),
+    }
+
+
+def compute_event_hash(event: dict[str, Any]) -> str:
+    body = dict(event)
+    body.pop("integrity_hash", None)
+    return _sha256_hex(body)
+
+
+def compute_event_id(event: dict[str, Any]) -> str:
+    return f"e:{compute_event_hash(event)}"
+
+
+def compute_head_hash(event: dict[str, Any]) -> str:
+    marker = {
+        "event_id": _normalize_string(event.get("event_id", "")),
+        "integrity_hash": _normalize_string(event.get("integrity_hash", "")),
+        "prev_hash": _normalize_string(event.get("prev_hash", "")),
+        "writer_id": _normalize_string(event.get("writer_id", "")),
+    }
+    return _sha256_hex(marker)
+
+
+def compute_checkpoint_hash(checkpoint: dict[str, Any]) -> str:
+    body = dict(checkpoint)
+    body.pop("summary_hash", None)
+    return _sha256_hex(body)
+
+
+def compute_view_hash(view: dict[str, Any]) -> str:
+    body = dict(view)
+    body.pop("view_hash", None)
+    return _sha256_hex(body)
+
+
+def normalize_index0_event(raw: Any) -> dict[str, Any] | None:
+    if not isinstance(raw, dict):
+        return None
+    modified_ts = _safe_int(raw.get("modified_ts", 0), default=0)
+    if modified_ts <= 0:
+        return None
+    event = {
+        "event_type": _normalize_string(raw.get("event_type", "")),
+        "subject_type": _normalize_string(raw.get("subject_type", "")),
+        "subject_id": _normalize_string(raw.get("subject_id", "")),
+        "subject_kind": _normalize_string(raw.get("subject_kind", "")),
+        "scope_path": _normalize_string(raw.get("scope_path", "")),
+        "actor_type": _normalize_string(raw.get("actor_type", "")),
+        "actor_id": _normalize_string(raw.get("actor_id", "")),
+        "writer_id": _normalize_string(raw.get("writer_id", "")),
+        "modified_ts": modified_ts,
+        "prev_hash": _normalize_string(raw.get("prev_hash", "")),
+        "classification": _normalize_string(raw.get("classification", "internal"))
+        or "internal",
+        "partition": _normalize_string(raw.get("partition", "standard")) or "standard",
+        "payload_ref": _normalize_mapping(raw.get("payload_ref")),
+        "links": _normalize_links(raw.get("links")),
+        "tags": _normalize_tags(raw.get("tags")),
+        "visibility": _normalize_string(raw.get("visibility", "private")) or "private",
+    }
+    for key in ("policy_ref", "source", "source_event_id", "summary"):
+        value = _normalize_string(raw.get(key, ""))
+        if value:
+            event[key] = value
+    required = (
+        event["event_type"],
+        event["subject_type"],
+        event["subject_id"],
+        event["writer_id"],
+    )
+    if not all(required):
+        return None
+    event["integrity_hash"] = _normalize_string(raw.get("integrity_hash", ""))
+    expected_hash = compute_event_hash(event)
+    if not event["integrity_hash"]:
+        event["integrity_hash"] = expected_hash
+    event["event_id"] = (
+        _normalize_string(raw.get("event_id", "")) or f"e:{expected_hash}"
+    )
+    return event
+
+
+def normalize_index0_checkpoint(raw: Any) -> dict[str, Any] | None:
+    if not isinstance(raw, dict):
+        return None
+    checkpoint_id = _normalize_string(raw.get("checkpoint_id", ""))
+    writer_id = _normalize_string(raw.get("writer_id", ""))
+    window_type = _normalize_string(raw.get("window_type", ""))
+    window_key = _normalize_string(raw.get("window_key", ""))
+    modified_ts = _safe_int(raw.get("modified_ts", 0), default=0)
+    if (
+        not checkpoint_id
+        or not writer_id
+        or not window_type
+        or not window_key
+        or modified_ts <= 0
+    ):
+        return None
+    rollup_raw = _normalize_mapping(raw.get("rollup"))
+    events_by_type = _normalize_mapping(rollup_raw.get("events_by_type"))
+    subjects_by_kind = _normalize_mapping(rollup_raw.get("subjects_by_kind"))
+    subjects = _normalize_tags(rollup_raw.get("subjects"))
+    checkpoint = {
+        "checkpoint_id": checkpoint_id,
+        "window_type": window_type,
+        "window_key": window_key,
+        "writer_id": writer_id,
+        "window_start_ts": _safe_int(raw.get("window_start_ts", 0), default=0),
+        "window_end_ts": _safe_int(raw.get("window_end_ts", 0), default=0),
+        "event_count": max(0, _safe_int(raw.get("event_count", 0), default=0)),
+        "head_hash": _normalize_string(raw.get("head_hash", "")),
+        "rollup": {
+            "events_by_type": {
+                _normalize_string(k): _safe_int(v, default=0)
+                for k, v in sorted(
+                    events_by_type.items(), key=lambda item: str(item[0])
+                )
+                if _normalize_string(k)
+            },
+            "subjects_by_kind": {
+                _normalize_string(k): _safe_int(v, default=0)
+                for k, v in sorted(
+                    subjects_by_kind.items(), key=lambda item: str(item[0])
+                )
+                if _normalize_string(k)
+            },
+            "subjects": subjects,
+        },
+        "modified_ts": modified_ts,
+    }
+    checkpoint["summary_hash"] = _normalize_string(
+        raw.get("summary_hash", "")
+    ) or compute_checkpoint_hash(checkpoint)
+    return checkpoint
+
+
+def normalize_canonical_view(
+    raw: Any, *, view_manifest: dict[str, Any] | None = None
+) -> dict[str, Any] | None:
+    if not isinstance(raw, dict):
+        return None
+    view_type = _normalize_string(raw.get("view_type", ""))
+    modified_ts = _safe_int(raw.get("modified_ts", 0), default=0)
+    if not view_type or modified_ts <= 0:
+        return None
+    if view_type in LOCAL_ONLY_VIEW_TYPES:
+        return None
+    if view_manifest:
+        local_only = set(view_manifest.get("local_only_view_types", []))
+        if view_type in local_only:
+            return None
+    view = {
+        "view_id": _normalize_string(raw.get("view_id", "")),
+        "view_type": view_type,
+        "scope_path": _normalize_string(raw.get("scope_path", "")),
+        "source_checkpoint_ids": _normalize_tags(raw.get("source_checkpoint_ids")),
+        "source_event_ids": _normalize_tags(raw.get("source_event_ids")),
+        "data": _normalize_mapping(raw.get("data")),
+        "modified_ts": modified_ts,
+    }
+    if not view["view_id"]:
+        return None
+    view["view_hash"] = _normalize_string(
+        raw.get("view_hash", "")
+    ) or compute_view_hash(view)
+    return view
+
+
+def normalize_head(raw: Any) -> dict[str, Any] | None:
+    if not isinstance(raw, dict):
+        return None
+    event_id = _normalize_string(raw.get("event_id", ""))
+    head_hash = _normalize_string(raw.get("head_hash", ""))
+    modified_ts = _safe_int(raw.get("modified_ts", 0), default=0)
+    if not event_id or not head_hash or modified_ts <= 0:
+        return None
+    return {"event_id": event_id, "head_hash": head_hash, "modified_ts": modified_ts}
+
+
+def _prefer_hashed_record(
+    current: dict[str, Any], incoming: dict[str, Any], *, hash_field: str
+) -> bool:
+    cur_ts = _safe_int(current.get("modified_ts", 0), default=0)
+    inc_ts = _safe_int(incoming.get("modified_ts", 0), default=0)
+    if inc_ts != cur_ts:
+        return inc_ts > cur_ts
+    return _normalize_string(incoming.get(hash_field, "")) > _normalize_string(
+        current.get(hash_field, "")
+    )
+
+
+def merge_system_index0(current: Any, incoming: Any) -> dict[str, Any]:
+    cur = normalize_index0(current)
+    inc = normalize_index0(incoming)
+
+    events = dict(cur["events"])
+    for event_id, event in inc["events"].items():
+        existing = events.get(event_id)
+        if existing is None:
+            events[event_id] = event
+            continue
+        if _canonical(existing) == _canonical(event):
+            continue
+        if _sha256_hex(event) > _sha256_hex(existing):
+            events[event_id] = event
+
+    checkpoints = dict(cur["checkpoints"])
+    for checkpoint_id, checkpoint in inc["checkpoints"].items():
+        existing = checkpoints.get(checkpoint_id)
+        if existing is None:
+            checkpoints[checkpoint_id] = checkpoint
+            continue
+        if _prefer_hashed_record(existing, checkpoint, hash_field="summary_hash"):
+            checkpoints[checkpoint_id] = checkpoint
+
+    view_manifest = normalize_view_manifest(
+        {
+            "version": max(
+                _safe_int(cur["view_manifest"].get("version", 1), default=1),
+                _safe_int(inc["view_manifest"].get("version", 1), default=1),
+            ),
+            "canonical_view_types": sorted(
+                set(cur["view_manifest"].get("canonical_view_types", []))
+                | set(inc["view_manifest"].get("canonical_view_types", []))
+            ),
+            "local_only_view_types": sorted(
+                set(cur["view_manifest"].get("local_only_view_types", []))
+                | set(inc["view_manifest"].get("local_only_view_types", []))
+            ),
+            "builder_versions": {
+                **cur["view_manifest"].get("builder_versions", {}),
+                **inc["view_manifest"].get("builder_versions", {}),
+            },
+        }
+    )
+
+    views = dict(cur["canonical_views"])
+    for view_id, view in inc["canonical_views"].items():
+        normalized_view = normalize_canonical_view(view, view_manifest=view_manifest)
+        if normalized_view is None:
+            continue
+        existing = views.get(view_id)
+        if existing is None:
+            views[view_id] = normalized_view
+            continue
+        if _prefer_hashed_record(existing, normalized_view, hash_field="view_hash"):
+            views[view_id] = normalized_view
+
+    heads = dict(cur["heads"])
+    for writer_id, head in inc["heads"].items():
+        existing = heads.get(writer_id)
+        if existing is None or _prefer_hashed_record(
+            existing, head, hash_field="head_hash"
+        ):
+            heads[writer_id] = head
+
+    merged = {
+        "schema_version": max(cur["schema_version"], inc["schema_version"]),
+        "events": dict(sorted(events.items())),
+        "checkpoints": dict(sorted(checkpoints.items())),
+        "canonical_views": dict(sorted(views.items())),
+        "view_manifest": view_manifest,
+        "heads": dict(sorted(heads.items())),
+        "stats": {},
+    }
+    merged["stats"] = recompute_index0_stats(merged)
+    return merged
+
+
+def recompute_index0_stats(index0: dict[str, Any]) -> dict[str, Any]:
+    events = _normalize_mapping(index0.get("events"))
+    checkpoints = _normalize_mapping(index0.get("checkpoints"))
+    heads = _normalize_mapping(index0.get("heads"))
+    stats = {
+        "event_count": len(events),
+        "checkpoint_count": len(checkpoints),
+        "writer_count": len(heads),
+        "last_compaction_ts": 0,
+        "last_validation_ts": 0,
+    }
+    checkpoint_ts = [
+        _safe_int(value.get("modified_ts", 0), default=0)
+        for value in checkpoints.values()
+        if isinstance(value, dict)
+    ]
+    head_ts = [
+        _safe_int(value.get("modified_ts", 0), default=0)
+        for value in heads.values()
+        if isinstance(value, dict)
+    ]
+    if checkpoint_ts:
+        stats["last_compaction_ts"] = max(checkpoint_ts)
+    if head_ts:
+        stats["last_validation_ts"] = max(head_ts)
+    return stats
diff --git a/src/seedpass/core/manager.py b/src/seedpass/core/manager.py
index 37144957..c490c425 100644
--- a/src/seedpass/core/manager.py
+++ b/src/seedpass/core/manager.py
@@ -245,7 +245,11 @@ class PasswordManager:
     deterministic_totp: bool = False
 
     def __init__(
-        self, fingerprint: Optional[str] = None, *, password: Optional[str] = None
+        self,
+        fingerprint: Optional[str] = None,
+        *,
+        password: Optional[str] = None,
+        bootstrap_only: bool = False,
     ) -> None:
         """Initialize the PasswordManager.
 
@@ -321,13 +325,16 @@ class PasswordManager:
         if fingerprint:
             # Load the specified profile without prompting
             self.select_fingerprint(fingerprint, password=password)
-        else:
+        elif not bootstrap_only:
             # Ensure a parent seed is set up before accessing the fingerprint directory
             self.setup_parent_seed()
             # Set the current fingerprint directory after selection
             self.fingerprint_dir = (
                 self.fingerprint_manager.get_current_fingerprint_dir()
             )
+        else:
+            self.current_fingerprint = None
+            self.fingerprint_dir = None
 
     @requires_unlocked
     def get_bip85_entropy(
@@ -1017,6 +1024,77 @@ class PasswordManager:
             print(colored(f"Error: Profile recovery failed: {exc}", "red"))
             return False
 
+    def recover_profile_with_blank_index_data(
+        self,
+        *,
+        fingerprint: str,
+        parent_seed: str,
+        password: str,
+    ) -> bool:
+        """Recover ``fingerprint`` with ``parent_seed`` and a blank local index."""
+        fingerprints = self.fingerprint_manager.list_fingerprints()
+        if fingerprint not in fingerprints:
+            raise SeedPassError("Selected profile does not exist.")
+
+        fingerprint_dir = self.fingerprint_manager.get_fingerprint_directory(
+            fingerprint
+        )
+        if not fingerprint_dir:
+            raise SeedPassError("Profile directory not found.")
+
+        if not self.validate_bip85_seed(parent_seed):
+            raise SeedPassError("Invalid BIP-85 seed phrase.")
+
+        computed_fp = generate_fingerprint(parent_seed)
+        if computed_fp != fingerprint:
+            raise SeedPassError("Seed does not match selected profile fingerprint.")
+
+        try:
+            self.current_fingerprint = fingerprint
+            self.fingerprint_manager.current_fingerprint = fingerprint
+            self.fingerprint_dir = fingerprint_dir
+            self.parent_seed = parent_seed
+
+            seed_bytes = Bip39SeedGenerator(parent_seed).Generate()
+            self.derive_key_hierarchy(seed_bytes)
+            index_key = base64.urlsafe_b64encode(self.KEY_STORAGE)
+            seed_key = self._derive_seed_key(password, fingerprint)
+
+            self.encryption_manager = EncryptionManager(index_key, fingerprint_dir)
+            seed_mgr = EncryptionManager(seed_key, fingerprint_dir)
+            self.vault = Vault(self.encryption_manager, fingerprint_dir)
+            self.config_manager = ConfigManager(
+                vault=self.vault,
+                fingerprint_dir=fingerprint_dir,
+            )
+
+            self._encrypt_parent_seed_compat(
+                seed_mgr,
+                parent_seed,
+                fingerprint,
+                mode=self._get_kdf_mode(),
+            )
+            self.store_hashed_password(password)
+
+            for stale_file in (
+                fingerprint_dir / "seedpass_entries_db.json.enc",
+                fingerprint_dir / "seedpass_passwords_db.json.enc",
+                fingerprint_dir / "seedpass_entries_db_checksum.txt",
+                fingerprint_dir / "seedpass_passwords_db_checksum.txt",
+            ):
+                try:
+                    stale_file.unlink()
+                except FileNotFoundError:
+                    pass
+
+            self.initialize_bip85()
+            self.initialize_managers()
+            self.start_background_sync()
+            return True
+        except Exception as exc:
+            logger.error("Profile recovery failed: %s", exc, exc_info=True)
+            raise SeedPassError(f"Profile recovery failed: {exc}") from exc
+
     def setup_encryption_manager(
         self,
         fingerprint_dir: Path,
@@ -1605,6 +1683,19 @@ class PasswordManager:
             print(colored(f"Error: Failed to generate BIP-85 seed: {e}", "red"))
             raise SeedPassError(f"Failed to generate BIP-85 seed: {e}") from e
 
+    def create_profile_from_generated_seed(
+        self,
+        *,
+        password: str,
+        seed: Optional[str] = None,
+    ) -> tuple[str, str]:
+        """Create a new profile from a generated seed and return ``(fingerprint, seed)``."""
+        new_seed = seed or self.generate_bip85_seed()
+        fingerprint = self._finalize_existing_seed(new_seed, password=password)
+        if not fingerprint:
+            raise SeedPassError("Failed to create profile from generated seed.")
+        return fingerprint, new_seed
+
     @requires_unlocked
     def save_and_encrypt_seed(
         self, seed: str, fingerprint_dir: Path, *, password: Optional[str] = None
@@ -2234,6 +2325,47 @@ class PasswordManager:
             self.notify("Starting with a new, empty vault.", level="INFO")
             return
 
+    def restore_from_nostr_with_guidance_data(
+        self,
+        *,
+        seed_phrase: str,
+        password: str,
+        continue_without_backup: bool = False,
+    ) -> tuple[str, bool]:
+        """Restore a profile from Nostr without interactive prompts.
+
+        Returns ``(fingerprint, have_backup)``.
+        """
+        have_backup = self.check_nostr_backup_exists(seed_phrase)
+        if not have_backup and not continue_without_backup:
+            raise SeedPassError("No Nostr backup found for this seed profile.")
+
+        fingerprint = self._finalize_existing_seed(seed_phrase, password=password)
+        if not fingerprint:
+            raise SeedPassError("Failed to initialize profile from provided seed.")
+
+        if have_backup:
+            success = self.attempt_initial_sync()
+            if not success:
+                raise SeedPassError("Failed to download or decrypt vault from Nostr.")
+        return fingerprint, have_backup
+
+    def restore_from_local_backup_data(
+        self,
+        *,
+        seed_phrase: str,
+        password: str,
+        backup_path: str,
+    ) -> str:
+        """Restore a profile from a local encrypted backup without prompts."""
+        fingerprint = self._finalize_existing_seed(seed_phrase, password=password)
+        if not fingerprint:
+            raise SeedPassError("Failed to initialize profile from provided seed.")
+        if not self.backup_manager:
+            raise SeedPassError("Backup manager is not initialized.")
+        self.backup_manager.restore_from_backup(backup_path)
+        return fingerprint
+
     def _clear_header_add_entry(self, subtitle: str) -> None:
         fp, parent_fp, child_fp = self.header_fingerprint_args
         clear_header_with_notification(
diff --git a/src/seedpass/core/sync_conflict.py b/src/seedpass/core/sync_conflict.py
index ebdc0e1b..1539cee9 100644
--- a/src/seedpass/core/sync_conflict.py
+++ b/src/seedpass/core/sync_conflict.py
@@ -4,6 +4,8 @@ import hashlib
 import json
 from typing import Any
 
+from .index0 import ensure_index0_payload, merge_system_index0
+
 TOMBSTONE_RETENTION_CAP = 2048
 
 
@@ -190,7 +192,8 @@ def merge_index_payloads(
     current: dict[str, Any], incoming: dict[str, Any], *, source_tag: str = ""
 ) -> dict[str, Any]:
     """Merge two index payloads using deterministic conflict resolution."""
-    out = dict(current) if isinstance(current, dict) else {}
+    out = ensure_index0_payload(dict(current) if isinstance(current, dict) else {})
+    incoming = ensure_index0_payload(incoming if isinstance(incoming, dict) else {})
     cur_entries = out.get("entries", {})
     if not isinstance(cur_entries, dict):
         cur_entries = {}
@@ -318,4 +321,14 @@ def merge_index_payloads(
         }
     )
     out["_sync_meta"] = meta
+    out_system = out.get("_system", {})
+    inc_system = incoming.get("_system", {})
+    if not isinstance(out_system, dict):
+        out_system = {}
+    if not isinstance(inc_system, dict):
+        inc_system = {}
+    out_system["index0"] = merge_system_index0(
+        out_system.get("index0"), inc_system.get("index0")
+    )
+    out["_system"] = out_system
     return out
diff --git a/src/seedpass/core/vault.py b/src/seedpass/core/vault.py
index a0a639d1..2124e25b 100644
--- a/src/seedpass/core/vault.py
+++ b/src/seedpass/core/vault.py
@@ -14,6 +14,7 @@ from .encryption import (
     USE_ORJSON,
     json_lib,
 )
+from .index0 import ensure_index0_payload
 from utils.key_derivation import KdfConfig, CURRENT_KDF_VERSION
 from utils.password_prompt import prompt_existing_password
 
@@ -232,12 +233,14 @@ class Vault:
         self.migrated_from_legacy = (
             legacy_detected or migration_performed or schema_migrated
         )
+        data = ensure_index0_payload(data)
         if return_migration_flags:
             return data, self.migrated_from_legacy, migration_performed
         return data
 
     def save_index(self, data: dict) -> None:
         """Encrypt and write password index."""
+        data = ensure_index0_payload(data)
         self.encryption_manager.save_json_data(
             data, self.index_file, kdf=self._hkdf_kdf()
         )
diff --git a/src/seedpass/tui_v3/app.py b/src/seedpass/tui_v3/app.py
index b1d6ef9b..3b9e3853 100644
--- a/src/seedpass/tui_v3/app.py
+++ b/src/seedpass/tui_v3/app.py
@@ -2,12 +2,14 @@ from __future__ import annotations
 import time
 from typing import Any, Callable
 
+from constants import APP_DIR
 from textual.app import App, ComposeResult
 from textual.binding import Binding
 from textual.reactive import reactive
 from textual.screen import Screen
-from textual.widgets import Header, Footer, Static
+from textual.widgets import Button, Input, Label, Static
 from textual.containers import Horizontal, Vertical
+from utils.fingerprint_manager import FingerprintManager
 
 from .widgets.header import RibbonHeader
 from .widgets.sidebar import SidebarContainer
@@ -171,6 +173,507 @@ class MainScreen(Screen):
         yield ActionBar(id="action-bar")
 
 
+class StartupScreen(Screen):
+    """Profile-selection and unlock screen for TUI v3 startup."""
+
+    BINDINGS = [
+        Binding("enter", "submit", "Unlock", show=False),
+        Binding("escape", "app.quit", "Quit", show=False),
+    ]
+
+    def __init__(
+        self,
+        *,
+        selected_fingerprint: str | None = None,
+        prompt: str | None = None,
+    ) -> None:
+        super().__init__()
+        self.selected_fingerprint = selected_fingerprint
+        self.prompt = prompt or "Select a seed profile and unlock to continue."
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="startup-shell"):
+            yield Label("SeedPass TUI v3", id="startup-title")
+            yield Static(self.prompt, id="startup-prompt")
+            yield Static("", id="startup-profiles")
+            yield Input(placeholder="Profile number", id="startup-profile-choice")
+            yield Input(
+                placeholder="Master password",
+                password=True,
+                id="startup-password",
+            )
+            with Horizontal(id="startup-actions"):
+                yield Button("Unlock", id="startup-unlock", variant="primary")
+                yield Button("Refresh", id="startup-refresh")
+                yield Button("Add New", id="startup-add")
+                yield Button("Recover", id="startup-recover")
+            yield Static("", id="startup-status")
+
+    def on_mount(self) -> None:
+        self.refresh_profiles()
+
+    def refresh_profiles(self) -> None:
+        profiles = self.app._list_boot_profiles()
+        lines = ["Available Seed Profiles:"]
+        if profiles:
+            for idx, profile in enumerate(profiles, start=1):
+                marker = (
+                    " *" if profile["fingerprint"] == self.selected_fingerprint else ""
+                )
+                lines.append(f"{idx}. {profile['label']}{marker}")
+        else:
+            lines.append("No existing seed profiles found.")
+        lines.append(f"{len(profiles) + 1}. Add a new seed profile")
+        lines.append(
+            f"{len(profiles) + 2}. Recover existing profile with blank local index"
+        )
+        lines.append("Q. Exit")
+        self.query_one("#startup-profiles", Static).update("\n".join(lines))
+        profile_input = self.query_one("#startup-profile-choice", Input)
+        if self.selected_fingerprint:
+            for idx, profile in enumerate(profiles, start=1):
+                if profile["fingerprint"] == self.selected_fingerprint:
+                    profile_input.value = str(idx)
+                    break
+        elif len(profiles) == 1 and not profile_input.value:
+            profile_input.value = "1"
+
+    def action_submit(self) -> None:
+        self._submit_unlock()
+
+    def on_input_submitted(self, _event: Input.Submitted) -> None:
+        self._submit_unlock()
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        button_id = event.button.id
+        if button_id == "startup-unlock":
+            self._submit_unlock()
+            return
+        if button_id == "startup-refresh":
+            self.refresh_profiles()
+            self._set_status("Profile list refreshed.")
+            return
+        if button_id == "startup-add":
+            self.app.push_screen(CreateProfileScreen())
+            return
+        if button_id == "startup-recover":
+            self.app.push_screen(RecoverProfileScreen())
+            return
+
+    def _set_status(self, message: str) -> None:
+        self.query_one("#startup-status", Static).update(message)
+
+    def _submit_unlock(self) -> None:
+        profiles = self.app._list_boot_profiles()
+        choice = self.query_one("#startup-profile-choice", Input).value.strip()
+        password = self.query_one("#startup-password", Input).value
+        if choice.lower() in {"q", "quit", "exit"}:
+            self.app.exit()
+            return
+        if not choice.isdigit():
+            self._set_status("Enter the profile number from the list above.")
+            return
+        selected = int(choice)
+        add_idx = len(profiles) + 1
+        recover_idx = len(profiles) + 2
+        if selected == add_idx:
+            self.app.push_screen(CreateProfileScreen())
+            return
+        if selected == recover_idx:
+            self.app.push_screen(RecoverProfileScreen())
+            return
+        if not (1 <= selected <= len(profiles)):
+            self._set_status("Invalid selection.")
+            return
+        if not password:
+            self._set_status("Enter the master password for the selected profile.")
+            return
+        fingerprint = profiles[selected - 1]["fingerprint"]
+        self.app._bootstrap_profile_session(fingerprint, password)
+
+    DEFAULT_CSS = """
+    StartupScreen {
+        align: center middle;
+        background: #999999;
+    }
+    #startup-shell {
+        width: 90;
+        max-width: 90;
+        border: heavy black;
+        background: #000000;
+        color: #ffffff;
+        padding: 1 2;
+    }
+    #startup-title {
+        text-style: bold;
+        margin-bottom: 1;
+    }
+    #startup-prompt {
+        color: #cccccc;
+        margin-bottom: 1;
+    }
+    #startup-profiles {
+        border: solid #ffffff;
+        padding: 1;
+        margin-bottom: 1;
+        min-height: 10;
+    }
+    #startup-profile-choice, #startup-password {
+        margin-bottom: 1;
+    }
+    #startup-actions {
+        height: auto;
+        margin-bottom: 1;
+    }
+    #startup-actions Button {
+        margin-right: 1;
+    }
+    #startup-status {
+        min-height: 2;
+        color: #daf2e5;
+    }
+    """
+
+
+class CreateProfileScreen(Screen):
+    """Create a new profile or import an existing seed inside TUI v3."""
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="startup-shell"):
+            yield Label("Create Seed Profile", id="startup-title")
+            yield Static(
+                "Modes: existing, words, generate, nostr, backup. This screen now covers the main legacy onboarding branches inside v3.",
+                id="startup-prompt",
+            )
+            yield Input(
+                placeholder="Mode: existing | words | generate | nostr | backup",
+                id="create-mode",
+            )
+            yield Input(
+                placeholder="Seed phrase (paste full phrase; for 'words' you can type the 12 words space-separated)",
+                id="create-seed",
+            )
+            yield Input(
+                placeholder="Backup path (required for backup mode)",
+                id="create-backup-path",
+            )
+            yield Input(
+                placeholder="Continue without remote backup? yes | no (used for nostr mode)",
+                id="create-nostr-empty-ok",
+            )
+            yield Input(
+                placeholder="Master password",
+                password=True,
+                id="create-password",
+            )
+            with Horizontal(id="startup-actions"):
+                yield Button("Word Entry", id="create-words")
+                yield Button("Generate Seed", id="create-generate")
+                yield Button("Create Profile", id="create-submit", variant="primary")
+                yield Button("Back", id="create-back")
+            yield Static("", id="create-status")
+
+    def on_mount(self) -> None:
+        self.query_one("#create-mode", Input).value = "existing"
+        self.query_one("#create-nostr-empty-ok", Input).value = "no"
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        button_id = event.button.id
+        if button_id == "create-back":
+            self.app.pop_screen()
+            return
+        if button_id == "create-words":
+            self.app.push_screen(SeedWordsScreen(on_done=self._apply_seed_words))
+            return
+        if button_id == "create-generate":
+            self._generate_seed()
+            return
+        if button_id == "create-submit":
+            self._submit()
+
+    def on_input_submitted(self, _event: Input.Submitted) -> None:
+        self._submit()
+
+    def _set_status(self, message: str) -> None:
+        self.query_one("#create-status", Static).update(message)
+
+    def _apply_seed_words(self, seed_phrase: str) -> None:
+        self.query_one("#create-mode", Input).value = "words"
+        self.query_one("#create-seed", Input).value = seed_phrase
+        self._set_status("Seed phrase captured from word-by-word entry.")
+
+    def _generate_seed(self) -> None:
+        try:
+            seed = self.app._generate_bootstrap_seed()
+            self.query_one("#create-mode", Input).value = "generate"
+            self.query_one("#create-seed", Input).value = seed
+            self._set_status(
+                "Generated new seed. Review it carefully and store it before creating the profile."
+            )
+        except Exception as e:
+            self._set_status(f"Seed generation failed: {e}")
+
+    def _submit(self) -> None:
+        mode = self.query_one("#create-mode", Input).value.strip().lower() or "existing"
+        seed = self.query_one("#create-seed", Input).value.strip()
+        backup_path = self.query_one("#create-backup-path", Input).value.strip()
+        continue_without_backup = self.query_one(
+            "#create-nostr-empty-ok", Input
+        ).value.strip().lower() in {"y", "yes", "true", "1"}
+        password = self.query_one("#create-password", Input).value
+        if not password:
+            self._set_status("Enter a master password.")
+            return
+        try:
+            if mode == "generate":
+                if not seed:
+                    seed = self.app._generate_bootstrap_seed()
+                fingerprint = self.app._create_generated_profile(
+                    password=password, seed=seed
+                )
+            elif mode == "nostr":
+                if not seed:
+                    self._set_status("Enter the seed phrase for Nostr restore.")
+                    return
+                fingerprint = self.app._restore_from_nostr_profile(
+                    seed=seed,
+                    password=password,
+                    continue_without_backup=continue_without_backup,
+                )
+            elif mode == "backup":
+                if not seed:
+                    self._set_status("Enter the seed phrase for backup restore.")
+                    return
+                if not backup_path:
+                    self._set_status("Enter the backup path for backup mode.")
+                    return
+                fingerprint = self.app._restore_from_backup_profile(
+                    seed=seed,
+                    password=password,
+                    backup_path=backup_path,
+                )
+            else:
+                if not seed:
+                    self._set_status("Enter the seed phrase to import.")
+                    return
+                fingerprint = self.app._create_existing_profile(
+                    seed=seed,
+                    password=password,
+                )
+            self.app._bootstrap_profile_session(fingerprint, password)
+        except Exception as e:
+            self._set_status(f"Profile creation failed: {e}")
+
+
+class SeedWordsScreen(Screen):
+    """Guided word-by-word seed entry for onboarding parity."""
+
+    def __init__(self, *, on_done: Callable[[str], None]) -> None:
+        super().__init__()
+        self._on_done = on_done
+        from mnemonic import Mnemonic
+
+        self._mnemonic = Mnemonic("english")
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="startup-shell"):
+            yield Label("Enter Seed Words", id="startup-title")
+            yield Static(
+                "Enter the 12-word seed phrase one word per field, following the legacy flow.",
+                id="startup-prompt",
+            )
+            yield Static("Progress: 0/12 words entered", id="seed-words-progress")
+            for idx in range(12):
+                yield Input(placeholder=f"Word {idx + 1}", id=f"seed-word-{idx + 1}")
+            with Horizontal(id="startup-actions"):
+                yield Button("Use Phrase", id="seed-words-submit", variant="primary")
+                yield Button("Back", id="seed-words-back")
+            yield Static("", id="seed-words-status")
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        if event.button.id == "seed-words-back":
+            self.app.pop_screen()
+            return
+        if event.button.id == "seed-words-submit":
+            self._submit()
+
+    def on_input_submitted(self, _event: Input.Submitted) -> None:
+        self._submit()
+
+    def on_input_changed(self, event: Input.Changed) -> None:
+        input_id = event.input.id or ""
+        if not input_id.startswith("seed-word-"):
+            return
+        self._refresh_progress()
+        value = event.value.strip().lower()
+        if not value:
+            self.query_one("#seed-words-status", Static).update(
+                f"{input_id.replace('seed-word-', 'Word ')} is empty."
+            )
+            return
+        if value not in self._mnemonic.wordlist:
+            self.query_one("#seed-words-status", Static).update(
+                f"{input_id.replace('seed-word-', 'Word ')} is not in the BIP-39 wordlist."
+            )
+            return
+        self.query_one("#seed-words-status", Static).update(
+            f"{input_id.replace('seed-word-', 'Word ')} accepted."
+        )
+
+    def _refresh_progress(self) -> None:
+        count = 0
+        invalid = 0
+        for idx in range(12):
+            value = self.query_one(f"#seed-word-{idx + 1}", Input).value.strip().lower()
+            if not value:
+                continue
+            count += 1
+            if value not in self._mnemonic.wordlist:
+                invalid += 1
+        suffix = f" | invalid: {invalid}" if invalid else ""
+        self.query_one("#seed-words-progress", Static).update(
+            f"Progress: {count}/12 words entered{suffix}"
+        )
+
+    def _submit(self) -> None:
+        words: list[str] = []
+        for idx in range(12):
+            value = self.query_one(f"#seed-word-{idx + 1}", Input).value.strip().lower()
+            if not value:
+                self.query_one("#seed-words-status", Static).update(
+                    f"Word {idx + 1} is required."
+                )
+                return
+            if value not in self._mnemonic.wordlist:
+                self.query_one("#seed-words-status", Static).update(
+                    f"Word {idx + 1} is not in the BIP-39 wordlist."
+                )
+                return
+            words.append(value)
+        phrase = " ".join(words)
+        if not self._mnemonic.check(phrase):
+            self.query_one("#seed-words-status", Static).update(
+                "The full 12-word phrase failed BIP-39 validation."
+            )
+            return
+        self.app.push_screen(
+            SeedWordsReviewScreen(
+                phrase=phrase,
+                on_confirm=self._confirm_phrase,
+            )
+        )
+
+    def _confirm_phrase(self, phrase: str) -> None:
+        self._on_done(phrase)
+        self.app.pop_screen()
+        self.app.pop_screen()
+
+
+class SeedWordsReviewScreen(Screen):
+    """Confirmation screen for the assembled seed phrase."""
+
+    def __init__(self, *, phrase: str, on_confirm: Callable[[str], None]) -> None:
+        super().__init__()
+        self._phrase = phrase
+        self._on_confirm = on_confirm
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="startup-shell"):
+            yield Label("Review Seed Phrase", id="startup-title")
+            yield Static(
+                "Confirm this phrase before it is applied to the create flow.",
+                id="startup-prompt",
+            )
+            yield Static(self._phrase, id="seed-review-phrase")
+            with Horizontal(id="startup-actions"):
+                yield Button(
+                    "Confirm Phrase", id="seed-review-confirm", variant="primary"
+                )
+                yield Button("Edit Words", id="seed-review-back")
+            yield Static("", id="seed-review-status")
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        if event.button.id == "seed-review-back":
+            self.app.pop_screen()
+            return
+        if event.button.id == "seed-review-confirm":
+            self._on_confirm(self._phrase)
+
+
+class RecoverProfileScreen(Screen):
+    """Recover an existing profile with a blank local index inside TUI v3."""
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="startup-shell"):
+            yield Label("Recover Existing Profile", id="startup-title")
+            yield Static(
+                "This matches the legacy recovery path: select an existing profile, provide the matching seed, and reset the local index.",
+                id="startup-prompt",
+            )
+            yield Static("", id="recover-profiles")
+            yield Input(placeholder="Profile number", id="recover-choice")
+            yield Input(placeholder="Seed phrase", id="recover-seed")
+            yield Input(
+                placeholder="Master password",
+                password=True,
+                id="recover-password",
+            )
+            with Horizontal(id="startup-actions"):
+                yield Button("Recover Profile", id="recover-submit", variant="primary")
+                yield Button("Back", id="recover-back")
+            yield Static("", id="recover-status")
+
+    def on_mount(self) -> None:
+        self.refresh_profiles()
+
+    def refresh_profiles(self) -> None:
+        profiles = self.app._list_boot_profiles()
+        lines = ["Available Seed Profiles:"]
+        for idx, profile in enumerate(profiles, start=1):
+            lines.append(f"{idx}. {profile['label']}")
+        self.query_one("#recover-profiles", Static).update("\n".join(lines))
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        button_id = event.button.id
+        if button_id == "recover-back":
+            self.app.pop_screen()
+            return
+        if button_id == "recover-submit":
+            self._submit()
+
+    def on_input_submitted(self, _event: Input.Submitted) -> None:
+        self._submit()
+
+    def _set_status(self, message: str) -> None:
+        self.query_one("#recover-status", Static).update(message)
+
+    def _submit(self) -> None:
+        profiles = self.app._list_boot_profiles()
+        choice = self.query_one("#recover-choice", Input).value.strip()
+        seed = self.query_one("#recover-seed", Input).value.strip()
+        password = self.query_one("#recover-password", Input).value
+        if not choice.isdigit():
+            self._set_status("Enter the profile number to recover.")
+            return
+        idx = int(choice)
+        if not (1 <= idx <= len(profiles)):
+            self._set_status("Invalid profile selection.")
+            return
+        if not seed or not password:
+            self._set_status("Seed phrase and master password are required.")
+            return
+        fingerprint = profiles[idx - 1]["fingerprint"]
+        try:
+            self.app._recover_profile(
+                fingerprint=fingerprint,
+                seed=seed,
+                password=password,
+            )
+            self.app._bootstrap_profile_session(fingerprint, password)
+        except Exception as e:
+            self._set_status(f"Recovery failed: {e}")
+
+
 class SeedPassTuiV3(App[None]):
     """
     SeedPass TUI v3 - Rebuilt from scratch for modularity and mockup fidelity.
@@ -256,21 +759,176 @@ class SeedPassTuiV3(App[None]):
         # Initialized services
         self.services: dict[str, Any] = {}
         self._initial_fingerprint = fingerprint
+        self._main_screen_initialized = False
 
     def on_mount(self) -> None:
-        """Initialize services and push the main screen."""
+        """Initialize provided services or start in profile-unlock mode."""
         self.processor = CommandProcessor(self)
+        self._initialize_factory_services()
+        if self.services:
+            self._enter_main_workspace(initial=True)
+        else:
+            self.present_startup_screen(
+                selected_fingerprint=self._initial_fingerprint,
+                prompt="Select a seed profile and unlock to enter SeedPass.",
+            )
+        # Global UI Heartbeat (for 2FA ticking etc)
+        self.set_interval(1.0, self.action_refresh_ui_quiet)
+
+    def _initialize_factory_services(self) -> None:
         for name, factory in self.factories.items():
             if factory:
                 try:
-                    self.services[name] = factory()
+                    service = factory()
                 except Exception as e:
                     self.log(f"Failed to init service {name}: {e}")
+                    continue
+                if service is not None:
+                    self.services[name] = service
 
-        self.active_fingerprint = self._initial_fingerprint or ""
-        self.push_screen(MainScreen())
-        # Global UI Heartbeat (for 2FA ticking etc)
-        self.set_interval(1.0, self.action_refresh_ui_quiet)
+    def _list_boot_profiles(self) -> list[dict[str, str]]:
+        try:
+            manager = FingerprintManager(APP_DIR)
+            return [
+                {"fingerprint": fp, "label": manager.display_name(fp)}
+                for fp in manager.list_fingerprints()
+            ]
+        except Exception as e:
+            self.log(f"Failed to list startup profiles: {e}")
+            return []
+
+    def present_startup_screen(
+        self,
+        *,
+        selected_fingerprint: str | None = None,
+        prompt: str | None = None,
+    ) -> None:
+        self.push_screen(
+            StartupScreen(
+                selected_fingerprint=selected_fingerprint,
+                prompt=prompt,
+            )
+        )
+
+    def _bootstrap_profile_session(self, fingerprint: str, password: str) -> None:
+        try:
+            from seedpass.core.api import (
+                ConfigService,
+                EntryService,
+                NostrService,
+                ProfileService,
+                SemanticIndexService,
+                SyncService,
+                UtilityService,
+                VaultService,
+            )
+            from seedpass.core.manager import PasswordManager
+
+            pm = PasswordManager(fingerprint=fingerprint, password=password)
+            self.services = {
+                "entry": EntryService(pm),
+                "profile": ProfileService(pm),
+                "config": ConfigService(pm),
+                "nostr": NostrService(pm),
+                "sync": SyncService(pm),
+                "utility": UtilityService(pm),
+                "vault": VaultService(pm),
+                "semantic": SemanticIndexService(pm),
+            }
+            self.active_fingerprint = pm.current_fingerprint or fingerprint
+            self.session_locked = False
+            self._enter_main_workspace(initial=not self._main_screen_initialized)
+            self.notify(f"Unlocked profile {self.active_fingerprint[:12]}")
+        except Exception as e:
+            try:
+                if isinstance(self.screen, StartupScreen):
+                    self.screen._set_status(f"Unlock failed: {e}")
+            except Exception:
+                pass
+            self.notify(f"Unlock failed: {e}", severity="error")
+
+    def _make_bootstrap_manager(self):
+        from seedpass.core.manager import PasswordManager
+
+        return PasswordManager(bootstrap_only=True)
+
+    def _generate_bootstrap_seed(self) -> str:
+        manager = self._make_bootstrap_manager()
+        return manager.generate_bip85_seed()
+
+    def _create_existing_profile(self, *, seed: str, password: str) -> str:
+        manager = self._make_bootstrap_manager()
+        fingerprint = manager.setup_existing_seed(seed=seed, password=password)
+        if not fingerprint:
+            raise RuntimeError("Profile creation did not return a fingerprint.")
+        return fingerprint
+
+    def _create_generated_profile(
+        self, *, password: str, seed: str | None = None
+    ) -> str:
+        manager = self._make_bootstrap_manager()
+        fingerprint, _generated_seed = manager.create_profile_from_generated_seed(
+            password=password,
+            seed=seed,
+        )
+        return fingerprint
+
+    def _recover_profile(self, *, fingerprint: str, seed: str, password: str) -> None:
+        manager = self._make_bootstrap_manager()
+        manager.recover_profile_with_blank_index_data(
+            fingerprint=fingerprint,
+            parent_seed=seed,
+            password=password,
+        )
+
+    def _restore_from_nostr_profile(
+        self,
+        *,
+        seed: str,
+        password: str,
+        continue_without_backup: bool,
+    ) -> str:
+        manager = self._make_bootstrap_manager()
+        fingerprint, _have_backup = manager.restore_from_nostr_with_guidance_data(
+            seed_phrase=seed,
+            password=password,
+            continue_without_backup=continue_without_backup,
+        )
+        return fingerprint
+
+    def _restore_from_backup_profile(
+        self,
+        *,
+        seed: str,
+        password: str,
+        backup_path: str,
+    ) -> str:
+        manager = self._make_bootstrap_manager()
+        return manager.restore_from_local_backup_data(
+            seed_phrase=seed,
+            password=password,
+            backup_path=backup_path,
+        )
+
+    def _resolve_active_fingerprint(self) -> str:
+        try:
+            manager = self.services["vault"]._manager
+            current = getattr(manager, "current_fingerprint", None)
+            if current:
+                return str(current)
+        except Exception:
+            pass
+        return self._initial_fingerprint or self.active_fingerprint or ""
+
+    def _enter_main_workspace(self, *, initial: bool) -> None:
+        self.active_fingerprint = self._resolve_active_fingerprint()
+        if initial or not self._main_screen_initialized:
+            self.push_screen(MainScreen())
+            self._main_screen_initialized = True
+            return
+        if isinstance(self.screen, StartupScreen):
+            self.pop_screen()
+        self.action_refresh()
 
     def on_command_palette_command_executed(
         self, message: CommandPalette.CommandExecuted
@@ -338,6 +996,8 @@ class SeedPassTuiV3(App[None]):
 
     def action_refresh(self) -> None:
         """Force a global UI refresh."""
+        if not self._main_screen_initialized:
+            return
         self.screen.query_one("#profile-tree")._refresh_tree()
         self.screen.query_one("#entry-data-table")._refresh_data()
         self.notify("UI Refreshed")
@@ -421,6 +1081,10 @@ class SeedPassTuiV3(App[None]):
             locker()
             self.session_locked = True
             self.notify("Vault locked")
+            self.present_startup_screen(
+                selected_fingerprint=self.active_fingerprint or None,
+                prompt="Vault locked. Re-enter your master password to continue.",
+            )
         except Exception as e:
             self.notify(f"Lock failed: {e}", severity="error")
 
@@ -442,6 +1106,9 @@ class SeedPassTuiV3(App[None]):
             except Exception:
                 unlocker(password)
             self.session_locked = False
+            if isinstance(self.screen, StartupScreen) and self._main_screen_initialized:
+                self.pop_screen()
+                self.action_refresh()
             self.notify("Vault unlocked")
         except Exception as e:
             self.notify(f"Unlock failed: {e}", severity="error")
diff --git a/src/seedpass/tui_v3/widgets/sidebar.py b/src/seedpass/tui_v3/widgets/sidebar.py
index 6bb11ad8..e3d7f044 100644
--- a/src/seedpass/tui_v3/widgets/sidebar.py
+++ b/src/seedpass/tui_v3/widgets/sidebar.py
@@ -70,8 +70,13 @@ class ProfileTree(Tree):
             self.app.notify(f"Opened Entry #{entry_id} from profile tree")
             return
 
-        self.app.active_fingerprint = value
-        self.app.notify(f"Switched to profile: {value[:8]}")
+        if value == self.app.active_fingerprint:
+            self.app.notify(f"Profile already active: {value[:8]}")
+            return
+        self.app.present_startup_screen(
+            selected_fingerprint=value,
+            prompt=f"Unlock {value[:12]} to switch profiles.",
+        )
 
 
 class SidebarContainer(Static):
diff --git a/src/tests/test_index0_core.py b/src/tests/test_index0_core.py
new file mode 100644
index 00000000..7aad3ba9
--- /dev/null
+++ b/src/tests/test_index0_core.py
@@ -0,0 +1,130 @@
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+from helpers import create_vault
+from nostr.backup_models import ChunkMeta, Manifest
+from seedpass.core.index0 import (
+    compute_event_hash,
+    compute_event_id,
+    ensure_index0_payload,
+    merge_system_index0,
+    normalize_index0,
+)
+
+
+def test_ensure_index0_payload_initializes_reserved_namespace():
+    payload = ensure_index0_payload({"schema_version": 4, "entries": {}})
+
+    assert payload["_system"]["index0"]["schema_version"] == 1
+    assert payload["_system"]["index0"]["events"] == {}
+    assert payload["_system"]["index0"]["canonical_views"] == {}
+    assert payload["_system"]["index0"]["stats"]["event_count"] == 0
+
+
+def test_merge_system_index0_is_order_independent_for_events_and_heads():
+    base_event = {
+        "event_type": "entry_modified",
+        "subject_type": "entry",
+        "subject_id": "1",
+        "subject_kind": "password",
+        "scope_path": "seed/root",
+        "actor_type": "user",
+        "actor_id": "fp1",
+        "writer_id": "writer:profile:fp1",
+        "modified_ts": 100,
+        "payload_ref": {"entry_id": "1"},
+        "links": [],
+        "tags": ["b", "a"],
+        "visibility": "private",
+        "classification": "internal",
+        "partition": "standard",
+    }
+    event_a = dict(base_event)
+    event_a["integrity_hash"] = compute_event_hash(event_a)
+    event_a["event_id"] = compute_event_id(event_a)
+    event_b = dict(base_event)
+    event_b["modified_ts"] = 200
+    event_b["prev_hash"] = "prev"
+    event_b["integrity_hash"] = compute_event_hash(event_b)
+    event_b["event_id"] = compute_event_id(event_b)
+
+    current = normalize_index0(
+        {
+            "events": {event_a["event_id"]: event_a},
+            "heads": {
+                "writer:profile:fp1": {
+                    "event_id": event_a["event_id"],
+                    "head_hash": "aaa",
+                    "modified_ts": 100,
+                }
+            },
+        }
+    )
+    incoming = normalize_index0(
+        {
+            "events": {event_b["event_id"]: event_b},
+            "heads": {
+                "writer:profile:fp1": {
+                    "event_id": event_b["event_id"],
+                    "head_hash": "bbb",
+                    "modified_ts": 200,
+                }
+            },
+        }
+    )
+
+    ab = merge_system_index0(current, incoming)
+    ba = merge_system_index0(incoming, current)
+
+    assert ab == ba
+    assert ab["stats"]["event_count"] == 2
+    assert ab["heads"]["writer:profile:fp1"]["head_hash"] == "bbb"
+
+
+def test_vault_save_and_load_index_normalizes_index0_namespace():
+    with TemporaryDirectory() as tmpdir:
+        base = Path(tmpdir)
+        vault, _ = create_vault(base)
+        vault.save_index({"schema_version": 4, "entries": {}})
+
+        loaded = vault.load_index()
+
+        assert "_system" in loaded
+        assert "index0" in loaded["_system"]
+        assert loaded["_system"]["index0"]["stats"]["writer_count"] == 0
+
+
+def test_manifest_supports_optional_index0_metadata_round_trip():
+    manifest = Manifest(
+        ver=1,
+        algo="gzip",
+        chunks=[ChunkMeta(id="c1", size=10, hash="abc", event_id="evt1")],
+        delta_since=123,
+        nonce="nonce",
+        index0={
+            "schema_version": 1,
+            "checkpoint_ids": ["cp:day:2026-03-05:writer:profile:fp1"],
+            "checkpoint_hashes": {"cp:day:2026-03-05:writer:profile:fp1": "abc123"},
+            "stream_heads": {"writer:profile:fp1": "head123"},
+        },
+    )
+    payload = {
+        "ver": manifest.ver,
+        "algo": manifest.algo,
+        "chunks": [meta.__dict__ for meta in manifest.chunks],
+        "delta_since": manifest.delta_since,
+        "nonce": manifest.nonce,
+        "index0": manifest.index0,
+    }
+
+    parsed = Manifest(
+        ver=payload["ver"],
+        algo=payload["algo"],
+        chunks=[ChunkMeta(**chunk) for chunk in payload["chunks"]],
+        delta_since=payload["delta_since"],
+        nonce=payload["nonce"],
+        index0=payload["index0"],
+    )
+
+    assert parsed.index0 is not None
+    assert parsed.index0["stream_heads"]["writer:profile:fp1"] == "head123"
diff --git a/src/tests/test_tui_v3_smoke.py b/src/tests/test_tui_v3_smoke.py
index 329121f1..a897e66c 100644
--- a/src/tests/test_tui_v3_smoke.py
+++ b/src/tests/test_tui_v3_smoke.py
@@ -5,9 +5,17 @@ from types import SimpleNamespace
 import pytest
 
 pytest.importorskip("textual")
-from textual.widgets import DataTable
+from textual.widgets import DataTable, Input
 
 from seedpass.tui_v3 import launch_tui3
+from seedpass.tui_v3.app import (
+    CreateProfileScreen,
+    RecoverProfileScreen,
+    SeedPassTuiV3,
+    SeedWordsScreen,
+    SeedWordsReviewScreen,
+    StartupScreen,
+)
 
 
 class V3EntryService:
@@ -126,6 +134,7 @@ async def test_tui3_palette_lock_unlock_and_session_status() -> None:
         await pilot.pause()
         assert app.session_locked is True
         assert vault.locked is True
+        assert isinstance(app.screen, StartupScreen)
         app.processor.execute("unlock hunter2")
         await pilot.pause()
         assert app.session_locked is False
@@ -169,3 +178,245 @@ async def test_tui3_grid_focus_refresh_enables_selection_after_runtime_add() ->
         table._refresh_data()
         await pilot.pause()
         assert table.row_count >= 4
+
+
+@pytest.mark.anyio
+async def test_tui3_starts_with_unlock_screen_when_services_are_not_preloaded() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: [
+        {"fingerprint": "EFBE51E70ED1B53A", "label": "Primary (EFBE51E70ED1B53A)"}
+    ]
+    captured: dict[str, str] = {}
+
+    def _bootstrap(fingerprint: str, password: str) -> None:
+        captured["fingerprint"] = fingerprint
+        captured["password"] = password
+
+    app._bootstrap_profile_session = _bootstrap
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        assert isinstance(app.screen, StartupScreen)
+        assert app.screen.query_one("#startup-profile-choice", Input).value == "1"
+        app.screen.query_one("#startup-password", Input).value = "hunter2"
+        await pilot.press("enter")
+        await pilot.pause()
+        assert captured == {
+            "fingerprint": "EFBE51E70ED1B53A",
+            "password": "hunter2",
+        }
+
+
+@pytest.mark.anyio
+async def test_tui3_create_profile_screen_uses_in_app_bootstrap_helpers() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: []
+    created: dict[str, str] = {}
+    booted: dict[str, str] = {}
+
+    def _create_existing_profile(*, seed: str, password: str) -> str:
+        created["seed"] = seed
+        created["password"] = password
+        return "NEWFP123"
+
+    def _bootstrap(fingerprint: str, password: str) -> None:
+        booted["fingerprint"] = fingerprint
+        booted["password"] = password
+
+    app._create_existing_profile = _create_existing_profile
+    app._bootstrap_profile_session = _bootstrap
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        app.push_screen(CreateProfileScreen())
+        await pilot.pause()
+        screen = app.screen
+        screen.query_one("#create-mode", Input).value = "existing"
+        screen.query_one("#create-seed", Input).value = (
+            "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+        )
+        screen.query_one("#create-password", Input).value = "hunter2"
+        await pilot.press("enter")
+        await pilot.pause()
+        assert created["password"] == "hunter2"
+        assert booted == {"fingerprint": "NEWFP123", "password": "hunter2"}
+
+
+@pytest.mark.anyio
+async def test_tui3_recover_profile_screen_uses_in_app_bootstrap_helpers() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: [
+        {"fingerprint": "EFBE51E70ED1B53A", "label": "Primary (EFBE51E70ED1B53A)"}
+    ]
+    recovered: dict[str, str] = {}
+    booted: dict[str, str] = {}
+
+    def _recover_profile(*, fingerprint: str, seed: str, password: str) -> None:
+        recovered["fingerprint"] = fingerprint
+        recovered["seed"] = seed
+        recovered["password"] = password
+
+    def _bootstrap(fingerprint: str, password: str) -> None:
+        booted["fingerprint"] = fingerprint
+        booted["password"] = password
+
+    app._recover_profile = _recover_profile
+    app._bootstrap_profile_session = _bootstrap
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        app.push_screen(RecoverProfileScreen())
+        await pilot.pause()
+        screen = app.screen
+        screen.query_one("#recover-choice", Input).value = "1"
+        screen.query_one("#recover-seed", Input).value = (
+            "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+        )
+        screen.query_one("#recover-password", Input).value = "hunter2"
+        await pilot.press("enter")
+        await pilot.pause()
+        assert recovered["fingerprint"] == "EFBE51E70ED1B53A"
+        assert booted == {
+            "fingerprint": "EFBE51E70ED1B53A",
+            "password": "hunter2",
+        }
+
+
+@pytest.mark.anyio
+async def test_tui3_create_profile_screen_supports_nostr_restore_mode() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: []
+    restored: dict[str, object] = {}
+    booted: dict[str, str] = {}
+
+    def _restore_from_nostr_profile(
+        *, seed: str, password: str, continue_without_backup: bool
+    ) -> str:
+        restored["seed"] = seed
+        restored["password"] = password
+        restored["continue_without_backup"] = continue_without_backup
+        return "NOSTRFP1"
+
+    def _bootstrap(fingerprint: str, password: str) -> None:
+        booted["fingerprint"] = fingerprint
+        booted["password"] = password
+
+    app._restore_from_nostr_profile = _restore_from_nostr_profile
+    app._bootstrap_profile_session = _bootstrap
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        app.push_screen(CreateProfileScreen())
+        await pilot.pause()
+        screen = app.screen
+        screen.query_one("#create-mode", Input).value = "nostr"
+        screen.query_one("#create-seed", Input).value = (
+            "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+        )
+        screen.query_one("#create-nostr-empty-ok", Input).value = "yes"
+        screen.query_one("#create-password", Input).value = "hunter2"
+        await pilot.press("enter")
+        await pilot.pause()
+        assert restored["continue_without_backup"] is True
+        assert booted == {"fingerprint": "NOSTRFP1", "password": "hunter2"}
+
+
+@pytest.mark.anyio
+async def test_tui3_create_profile_screen_supports_backup_restore_mode() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: []
+    restored: dict[str, str] = {}
+    booted: dict[str, str] = {}
+
+    def _restore_from_backup_profile(
+        *, seed: str, password: str, backup_path: str
+    ) -> str:
+        restored["seed"] = seed
+        restored["password"] = password
+        restored["backup_path"] = backup_path
+        return "BACKUPFP1"
+
+    def _bootstrap(fingerprint: str, password: str) -> None:
+        booted["fingerprint"] = fingerprint
+        booted["password"] = password
+
+    app._restore_from_backup_profile = _restore_from_backup_profile
+    app._bootstrap_profile_session = _bootstrap
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        app.push_screen(CreateProfileScreen())
+        await pilot.pause()
+        screen = app.screen
+        screen.query_one("#create-mode", Input).value = "backup"
+        screen.query_one("#create-seed", Input).value = (
+            "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+        )
+        screen.query_one("#create-backup-path", Input).value = "/tmp/profile-backup.enc"
+        screen.query_one("#create-password", Input).value = "hunter2"
+        await pilot.press("enter")
+        await pilot.pause()
+        assert restored["backup_path"] == "/tmp/profile-backup.enc"
+        assert booted == {"fingerprint": "BACKUPFP1", "password": "hunter2"}
+
+
+@pytest.mark.anyio
+async def test_tui3_word_by_word_seed_entry_feeds_create_profile_screen() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: []
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        app.push_screen(CreateProfileScreen())
+        await pilot.pause()
+        create_screen = app.screen
+        assert isinstance(create_screen, CreateProfileScreen)
+        create_screen.query_one("#create-words").press()
+        await pilot.pause()
+        assert isinstance(app.screen, SeedWordsScreen)
+        for idx, word in enumerate(
+            [
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "abandon",
+                "about",
+            ],
+            start=1,
+        ):
+            app.screen.query_one(f"#seed-word-{idx}", Input).value = word
+        await pilot.press("enter")
+        await pilot.pause()
+        assert isinstance(app.screen, SeedWordsReviewScreen)
+        app.screen.query_one("#seed-review-confirm").press()
+        await pilot.pause()
+        assert isinstance(app.screen, CreateProfileScreen)
+        assert app.screen.query_one("#create-mode", Input).value == "words"
+        assert (
+            app.screen.query_one("#create-seed", Input).value
+            == "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+        )
+
+
+@pytest.mark.anyio
+async def test_tui3_word_entry_flags_invalid_bip39_word() -> None:
+    app = SeedPassTuiV3()
+    app._list_boot_profiles = lambda: []
+
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        app.push_screen(SeedWordsScreen(on_done=lambda _phrase: None))
+        await pilot.pause()
+        app.screen.query_one("#seed-word-1", Input).value = "notaword"
+        await pilot.pause()
+        status = str(app.screen.query_one("#seed-words-status").render())
+        progress = str(app.screen.query_one("#seed-words-progress").render())
+        assert "not in the BIP-39 wordlist" in status
+        assert "invalid: 1" in progress
diff --git a/src/tests/test_typer_cli.py b/src/tests/test_typer_cli.py
index 931023ce..2f082613 100644
--- a/src/tests/test_typer_cli.py
+++ b/src/tests/test_typer_cli.py
@@ -684,6 +684,7 @@ def test_capabilities_json():
     payload = json.loads(result.stdout)
     assert payload["schema_version"] == 1
     assert "cli" in payload["interfaces"]
+    assert payload["interfaces"]["cli"]["default_interface"] == "tui3"
     assert "agent" in payload["interfaces"]["cli"]["root_commands"]
     assert "tui3" in payload["interfaces"]["cli"]["root_commands"]
     assert "legacy" in payload["interfaces"]["cli"]["root_commands"]
@@ -1011,8 +1012,23 @@ def test_update_checksum_command(monkeypatch):
     assert called.get("called") is True
 
 
-def test_root_tui2_forward_fingerprint(monkeypatch):
-    """Ensure --fingerprint is forwarded when launching default TUI v2."""
+def test_root_tui3_forward_fingerprint(monkeypatch):
+    """Ensure --fingerprint is forwarded when launching default TUI v3."""
+    called = {}
+
+    def fake_launch(**kwargs):
+        called["fp"] = kwargs.get("fingerprint")
+        called["factory"] = kwargs.get("entry_service_factory")
+        return True
+
+    monkeypatch.setattr(cli, "launch_tui3", fake_launch)
+    result = runner.invoke(app, ["--fingerprint", "abc"])
+    assert result.exit_code == 0
+    assert called.get("fp") == "abc"
+    assert called.get("factory") is None
+
+
+def test_root_explicit_tui2_forward_fingerprint(monkeypatch):
     called = {}
 
     def fake_launch(**kwargs):
@@ -1022,7 +1038,7 @@ def test_root_tui2_forward_fingerprint(monkeypatch):
 
     monkeypatch.setattr(cli, "_get_entry_service", lambda _ctx: object())
     monkeypatch.setattr(cli, "launch_tui2", fake_launch)
-    result = runner.invoke(app, ["--fingerprint", "abc"])
+    result = runner.invoke(app, ["--tui", "v2", "--fingerprint", "abc"])
     assert result.exit_code == 0
     assert called.get("fp") == "abc"
     assert callable(called.get("factory"))
@@ -1095,8 +1111,8 @@ def test_tui2_check(monkeypatch):
 def test_tui3_check(monkeypatch):
     monkeypatch.setattr(
         cli,
-        "check_tui2_runtime",
-        lambda: {"status": "ok", "backend": "textual", "textual_available": True},
+        "check_tui3_runtime",
+        lambda: {"status": "ok", "backend": "textual-v3", "textual_available": True},
     )
     result = runner.invoke(app, ["tui3", "--check"])
     assert result.exit_code == 0
@@ -1153,24 +1169,24 @@ def test_tui2_fallback_legacy_strips_subcommand_argv(monkeypatch):
     assert called.get("argv") == []
 
 
-def test_root_fallback_legacy_when_tui2_unavailable(monkeypatch):
-    called = {}
-    monkeypatch.setattr(cli, "_get_entry_service", lambda _ctx: object())
-    monkeypatch.setattr(cli, "launch_tui2", lambda **_: False)
+def test_root_tui3_unavailable_returns_error(monkeypatch):
+    monkeypatch.setattr(cli, "launch_tui3", lambda **_: False)
+    result = runner.invoke(app, ["--fingerprint", "abc"])
+    assert result.exit_code == 1
+    assert "TUI v3 runtime unavailable" in result.stderr
+    assert "seedpass tui2" in result.stderr
+    assert "seedpass legacy" in result.stderr
 
-    def fake_main(*, fingerprint=None):
-        called["fp"] = fingerprint
-        return 0
 
+def test_root_tui3_does_not_preflight_entry_service(monkeypatch):
     monkeypatch.setattr(
         cli,
-        "importlib",
-        SimpleNamespace(import_module=lambda _: SimpleNamespace(main=fake_main)),
+        "_get_entry_service",
+        lambda _ctx: (_ for _ in ()).throw(RuntimeError("should not run")),
     )
-    result = runner.invoke(app, ["--fingerprint", "abc"])
+    monkeypatch.setattr(cli, "launch_tui3", lambda **_: True)
+    result = runner.invoke(app, [])
     assert result.exit_code == 0
-    assert called.get("fp") == "abc"
-    assert "falling back to legacy TUI" in result.stdout
 
 
 def test_tui2_preflight_failure_without_fallback(monkeypatch):