diff --git a/docs/lib-overview.md b/docs/lib-overview.md
new file mode 100644
index 0000000..fbce7ce
--- /dev/null
+++ b/docs/lib-overview.md
@@ -0,0 +1,58 @@
+# src/lib.mjs: Core Logic Overview
+
+## Summary
+`src/lib.mjs` is the orchestration engine for Torch. It implements the high-level commands (`check`, `lock`, `list`, `complete`) that coordinate between local configuration, the file system (task logs), and Nostr relays (distributed locks).
+
+It is designed to be:
+- **Stateless**: No persistent local database; relies on Nostr events and flat files.
+- **Race-Condition Safe**: Uses a commit-wait-reveal pattern to handle concurrent agent starts.
+- **Dependency Injected**: Nearly all external side-effects (relays, time, FS) can be mocked.
+
+## Public API
+
+### `cmdCheck(cadence, deps)`
+Aggregates the current state of the world for a given cadence.
+- **Inputs**: Cadence ('daily'/'weekly').
+- **Outputs**: JSON object with lists of `locked`, `completed`, `paused`, and `available` agents.
+- **Side Effects**: Queries relays, reads `task-logs/`, reads `torch-config.json`.
+
+### `cmdLock(agent, cadence, dryRun, deps)`
+Attempts to claim a task.
+- **Returns**: `{ status: 'ok', eventId: '...' }`
+- **Throws**: `ExitError(3)` if the lock is denied (already active, completed, or race lost).
+
+### `cmdComplete(agent, cadence, dryRun, deps)`
+Finalizes a task.
+- **Action**: Publishes a permanent event (no expiration) with `status: 'completed'`.
+- **Constraint**: Requires an existing active lock for the agent.
+
+### `cmdList(cadence, deps)`
+Displays a CLI-friendly table of active locks.
+
+## Locking Flow (Sequence)
+
+1. **Check**: Query relays for any existing valid lock for `(agent, cadence, date)`.
+   - If found and `status=completed`: **Abort** (Task done).
+   - If found and `status=started` (and not expired): **Abort** (Agent busy).
+2. **Generate**: Create a new ephemeral Nostr keypair.
+3. **Build**: Create a signed event (Kind 30078) with:
+   - Tags: `d` (identifier), `expiration`, `t` (search tags).
+   - Content: JSON payload with metadata.
+4. **Publish**: Send to all configured relays.
+5. **Race Check**:
+   - Wait `RACE_CHECK_DELAY_MS` (default 2000ms).
+   - Query relays again.
+   - If another valid event exists with an *earlier* `created_at`: **Abort** (Race lost).
+   - Otherwise: **Success**.
+
+## Key Invariants
+
+- **Uniqueness**: Only one valid lock per (agent, cadence, date) should exist at a time.
+- **Expiration**: All locks must have an `expiration` tag (NIP-40) to prevent zombies, except completion events.
+- **Completion**: A completion event is permanent (no expiration) and effectively "freezes" the slot for that date.
+
+## When to Change
+
+- **Protocol Upgrades**: If changing the Nostr event structure or tags.
+- **Concurrency Tuning**: Adjusting `RACE_CHECK_DELAY_MS` or retry logic.
+- **New Commands**: Adding new lifecycle states (e.g., `failed` or `paused` via CLI).
diff --git a/src/context/CONTEXT_2026-02-14T21-30-00Z.md b/src/context/CONTEXT_2026-02-14T21-30-00Z.md
new file mode 100644
index 0000000..0f37987
--- /dev/null
+++ b/src/context/CONTEXT_2026-02-14T21-30-00Z.md
@@ -0,0 +1,9 @@
+# Context: 2026-02-14T21:30:00Z - docs-code-investigator
+
+## Plan
+1.  **Target**: `src/lib.mjs` (Core logic, ~700 LOC).
+2.  **Goal**: Add JSDoc and flow comments to clarify locking, checking, and completion logic.
+3.  **Rationale**: This file orchestrates the entire Torch system but lacks detailed documentation for its exported functions.
+4.  **Artifacts**:
+    *   Inline JSDoc in `src/lib.mjs`.
+    *   `docs/lib-overview.md` for high-level documentation.
diff --git a/src/lib.mjs b/src/lib.mjs
index 38dd2e4..b671af9 100644
--- a/src/lib.mjs
+++ b/src/lib.mjs
@@ -40,6 +40,15 @@ useWebSocketImplementation(WebSocket);
 // Re-export for backward compatibility/library usage
 export { parseLockEvent, cmdDashboard, _queryLocks as queryLocks, _publishLock as publishLock };
 
+/**
+ * Scans the local log directory to identify agents that have already completed their task
+ * for the current period (daily or weekly).
+ *
+ * @param {string} cadence - 'daily' or 'weekly'
+ * @param {string} logDir - Path to the log directory (e.g., 'task-logs')
+ * @param {Object} deps - Dependency injection for testing
+ * @returns {Promise<Set<string>>} - Set of agent names that have completed their task
+ */
 async function getCompletedAgents(cadence, logDir, deps) {
   const { readdir = fs.readdir, getDateStr = todayDateStr, getIsoWeek = getIsoWeekStr } = deps;
   const completed = new Set();
@@ -77,6 +86,20 @@ async function getCompletedAgents(cadence, logDir, deps) {
   return completed;
 }
 
+/**
+ * Checks the status of the repository locks for a given cadence.
+ *
+ * It aggregates data from three sources:
+ * 1. Configuration (paused agents)
+ * 2. Local logs (completed agents)
+ * 3. Nostr relays (current active locks)
+ *
+ * It outputs a JSON object describing the state (locked, available, excluded agents).
+ *
+ * @param {string} cadence - 'daily' or 'weekly'
+ * @param {Object} [deps] - Dependency injection
+ * @returns {Promise<Object>} - The check result object
+ */
 export async function cmdCheck(cadence, deps = {}) {
   const {
     getRelays = _getRelays,
@@ -145,6 +168,23 @@ export async function cmdCheck(cadence, deps = {}) {
   return result;
 }
 
+/**
+ * Attempts to acquire an exclusive lock for an agent on the specified cadence.
+ *
+ * Algorithm:
+ * 1. Validate agent against the roster.
+ * 2. Query relays for existing valid locks (checking for conflicts).
+ * 3. Generate a new ephemeral keypair and build a lock event (kind 30078).
+ * 4. Publish the lock event to relays.
+ * 5. Wait for propagation (raceCheckDelayMs) and re-query to confirm no earlier lock won the race.
+ *
+ * @param {string} agent - Agent name
+ * @param {string} cadence - 'daily' or 'weekly'
+ * @param {boolean} [dryRun=false] - If true, skips publishing
+ * @param {Object} [deps] - Dependency injection
+ * @returns {Promise<{status: string, eventId: string}>}
+ * @throws {ExitError} If lock is denied (already locked, completed, or race lost)
+ */
 export async function cmdLock(agent, cadence, dryRun = false, deps = {}) {
   const {
     getRelays = _getRelays,
@@ -278,6 +318,14 @@ export async function cmdLock(agent, cadence, dryRun = false, deps = {}) {
   return { status: 'ok', eventId: event.id };
 }
 
+/**
+ * Lists all active locks for the specified cadence (or all cadences if null).
+ * It prints a formatted table to stdout with lock age, TTL, and event ID.
+ *
+ * @param {string|null} cadence - Filter by cadence ('daily', 'weekly') or null for all
+ * @param {Object} [deps] - Dependency injection
+ * @returns {Promise<void>}
+ */
 export async function cmdList(cadence, deps = {}) {
   const {
     getRelays = _getRelays,
@@ -350,6 +398,21 @@ export async function cmdList(cadence, deps = {}) {
   }
 }
 
+/**
+ * Marks a task as permanently completed by publishing a new lock event with
+ * `status: 'completed'` and no expiration.
+ *
+ * This function:
+ * 1. Verifies that the agent currently holds a valid lock.
+ * 2. Publishes a replacement event that preserves the original `startedAt` time.
+ *
+ * @param {string} agent - Agent name
+ * @param {string} cadence - 'daily' or 'weekly'
+ * @param {boolean} [dryRun=false] - If true, skips publishing
+ * @param {Object} [deps] - Dependency injection
+ * @returns {Promise<{status: string, eventId: string}>}
+ * @throws {ExitError} If no active lock exists for the agent
+ */
 export async function cmdComplete(agent, cadence, dryRun = false, deps = {}) {
   const {
     getRelays = _getRelays,
@@ -440,6 +503,12 @@ export async function cmdComplete(agent, cadence, dryRun = false, deps = {}) {
   return { status: 'completed', eventId: event.id };
 }
 
+/**
+ * Parses command-line arguments into a structured object.
+ *
+ * @param {string[]} argv - Arguments from process.argv.slice(2)
+ * @returns {Object} - Parsed arguments (command, flags, values)
+ */
 function parseArgs(argv) {
   const args = {
     command: null,
@@ -568,6 +637,12 @@ Exit codes:
   3  Lock denied (already locked or race lost)`);
 }
 
+/**
+ * Main entry point for the torch-lock CLI.
+ * Dispatches to specific commands (check, lock, complete, etc.) based on argv.
+ *
+ * @param {string[]} argv - Arguments from process.argv.slice(2)
+ */
 export async function main(argv) {
   try {
     const args = parseArgs(argv);
diff --git a/task-logs/daily/2026-02-14T21-30-00Z__docs-code-investigator__completed.md b/task-logs/daily/2026-02-14T21-30-00Z__docs-code-investigator__completed.md
new file mode 100644
index 0000000..5013fcc
--- /dev/null
+++ b/task-logs/daily/2026-02-14T21-30-00Z__docs-code-investigator__completed.md
@@ -0,0 +1,15 @@
+---
+agent: docs-code-investigator
+status: completed
+created_at: 2026-02-14T21:30:00Z
+---
+# docs-code-investigator (daily) - 2026-02-14
+
+## Task
+Document `src/lib.mjs`.
+
+## Outcome
+- Added JSDoc for exported functions (`cmdCheck`, `cmdLock`, `cmdList`, `cmdComplete`).
+- Added flow comments for complex logic (`cmdLock`, `cmdComplete`).
+- Created `docs/lib-overview.md`.
+- Verified with `npm test` and `npm run lint`.