dejavu: a memory prosthesis with teeth for your AI coding agent

My agent kept retrying the same failing command across sessions. Rules files didn't stop it — agents forget between sessions, and markdown can't enforce anything. So I built dejavu: an OpenCode plugin that mechanically detects recurring tool-call failures and promotes them into enforced gates.

How it works

tool call fails  →  signature normalized (paths/numbers/hashes stripped)
                 →  pattern-key counted, sessions tracked
                 →  3 failures across 2 sessions  →  gate promoted
next attempt     →  [dejavu] REMINDER (call aborted, agent sees the correction)
retry fails      →  hard BLOCK for the rest of the session

No LLM in the hot path — normalized signatures and counters only.

Design decisions that matter

• Remind first, block on repeat. Pure blocking starts an arms race (block npm → agent switches to pnpm). A reminder with a CORRECTION teaches; the block is reserved for ignored reminders.
• Diagnostics never block. grep/tsc/pytest exiting 1 is their normal "found nothing" outcome. Only non-diagnostic bash can ever become a blocking gate.
• Two scopes. Repo quirks live in <repo>/.opencode/dejavu/ (committable); patterns seen in 2+ projects are agent habits and escalate to the global store.
• Gates rot. 60 days without recurrence → expired. And recurredAfterGate tells you when a gate fires but doesn't teach.
• Secrets never persist. Every signature and snippet is scrubbed (OpenAI/Anthropic/AWS/GitHub/Stripe/JWT/PEM/DB-conn patterns) before touching disk.

Install

// ~/.config/opencode/opencode.json
{ "plugin": ["opencode-dejavu"] }

TypeScript + Bun, zero runtime deps, MIT.

Repo: https://github.com/WhiteBite/opencode-dejavu · npm: opencode-dejavu

Feedback welcome from anyone running long-lived agent setups.