ver 0.9

echo-memory.plugin.src/skills/echo-memory/references/operating-contract.md

@@ -40,6 +40,6 @@ Assume clients may operate without filesystem access, through the Obsidian Local
 The vault is a **shared** substrate — Claude Code, CoWork, and other REST/MCP clients may operate on it concurrently. The REST API offers no transactions, so writers coordinate cooperatively:
 
 - Single-line, overwrite-style files (`_agent/heartbeat/last-session.md`, `current-context.md::Scope`) and append targets (`inbox.md`, `## Agent Log`) assume **one writer at a time**. Two sessions writing at once can clobber or duplicate.
-- Before a burst of writes in a session that may overlap another, take the advisory lock (`echo.sh lock <id>` → `_agent/locks/vault.lock`) and release it at session end. The lock is cooperative with a TTL (stale locks are reclaimable); it is a courtesy, not a hard mutex.
-- Idempotent append (read-before-POST, via `echo.sh append`) is the second line of defense against duplicate lines from retries or overlapping sessions.
+- Before a burst of writes in a session that may overlap another, take the advisory lock (`echo.py lock <id>` → `_agent/locks/vault.lock`) and release it at session end. The lock is read-back-confirmed and cooperative with a TTL (stale locks are reclaimable); it is a courtesy, not a hard mutex.
+- Idempotent append (read-before-POST, whole-line match, via `echo.py append`) is the second line of defense against duplicate lines from retries or overlapping sessions.
 - Status-check every write. A write that returns `>= 400` did **not** land — surface it rather than assuming success.