The latest articles on DEV Community by Dan (@whitebite). https://dev.to/whitebite https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4091167%2F6c961dad-9ee7-4f2e-867b-e53c05d280b3.jpg https://dev.to/whitebite en Dan Sun, 23 Aug 2026 18:46:21 +0000 https://dev.to/whitebite/dejavu-a-memory-prosthesis-with-teeth-for-your-ai-coding-agent-1h52 https://dev.to/whitebite/dejavu-a-memory-prosthesis-with-teeth-for-your-ai-coding-agent-1h52 <p>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.</p> <h2> How it works </h2> <div class="highlight js-code-highlight"> <pre class="highlight plaintext"><code>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 </code></pre> </div> <p>No LLM in the hot path — normalized signatures and counters only.</p> <h2> Design decisions that matter </h2> <ul> <li> <strong>Remind first, block on repeat.</strong> Pure blocking starts an arms race (block <code>npm</code> → agent switches to <code>pnpm</code>). A reminder with a CORRECTION teaches; the block is reserved for ignored reminders.</li> <li> <strong>Diagnostics never block.</strong> <code>grep</code>/<code>tsc</code>/<code>pytest</code> exiting 1 is their normal "found nothing" outcome. Only non-diagnostic bash can ever become a blocking gate.</li> <li> <strong>Two scopes.</strong> Repo quirks live in <code>&lt;repo&gt;/.opencode/dejavu/</code> (committable); patterns seen in 2+ projects are agent habits and escalate to the global store.</li> <li> <strong>Gates rot.</strong> 60 days without recurrence → expired. And <code>recurredAfterGate</code> tells you when a gate fires but doesn't teach.</li> <li> <strong>Secrets never persist.</strong> Every signature and snippet is scrubbed (OpenAI/Anthropic/AWS/GitHub/Stripe/JWT/PEM/DB-conn patterns) before touching disk.</li> </ul> <h2> Install </h2> <div class="highlight js-code-highlight"> <pre class="highlight json-doc"><code><span class="c1">// ~/.config/opencode/opencode.json</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="nl">"plugin"</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="s2">"opencode-dejavu"</span><span class="p">]</span><span class="w"> </span><span class="p">}</span><span class="w"> </span></code></pre> </div> <p>TypeScript + Bun, zero runtime deps, MIT.</p> <p>Repo: <a href="https://github.com/WhiteBite/opencode-dejavu" rel="noopener noreferrer">https://github.com/WhiteBite/opencode-dejavu</a> · npm: <code>opencode-dejavu</code></p> <p>Feedback welcome from anyone running long-lived agent setups.<br> <a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Foxel3jlvi8aciklw512w.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Foxel3jlvi8aciklw512w.png" alt=" " width="800" height="400"></a></p> opencode ai devtools typescript