Show HN: Provenance and decay for AI agent memory

Stalebrain, a new open-source tool from stalebrainlabs, audits AI agent memory files (CLAUDE.md, AGENTS.md, .cursorrules, GEMINI.md, Copilot instructions, and 18+ other locations across 13 agents) against current code, using git history to verify claims and stamp them with dates. The tool, installable via uv, pip, or git, provides verdicts, commit evidence, and ready-to-apply fixes for stale or false claims, aiming to prevent agents from acting on outdated instructions.

Your AI agent's memory files are lying to it. stalebrain finds every lie, proves it with commits, and hands you the fix. Install install · Demo see-it-in-action · What it does what-it-does · How it compares how-it-compares · Troubleshooting troubleshooting · License license Type /stale-brain in your AI coding assistant and it audits every agent memory file in your repo CLAUDE.md, AGENTS.md, .cursorrules, GEMINI.md, Copilot instructions, 18+ locations across 13 agents against the code as it exists today. Claims that check out get a dated stamp. Claims that don't get a verdict, the commits that prove it, and a ready-to-apply fix. Not a linter. A trust model: after one audit, every claim in agent memory carries an age, a verification date, and cited evidence. Prerequisite: a repo with git history. That's it. With uv or pip recommended, works inside Claude Code or any CLI uv tool install stalebrain or: pip install stalebrain / pipx install stalebrain stalebrain install user-level: every repo, Claude Code CLI and desktop app stalebrain install --project . or just this repo One-shot without installing anything permanent: uvx stalebrain install With git alone project-level git clone https://github.com/stalebrainlabs/stalebrain .claude/skills/stale-brain or user-level available in every repo git clone https://github.com/stalebrainlabs/stalebrain ~/.claude/skills/stale-brain Then type /stale-brain , or say "audit my agent memory". Desktop / no terminal at all stalebrain install covers the Claude Code desktop app it reads the same user-level skills folder . For every other desktop chat ChatGPT, Gemini, Claude.ai , run stalebrain portable to print the single-file protocol, or just copy PORTABLE.md /stalebrainlabs/stalebrain/blob/main/PORTABLE.md and paste it into the chat. Any other assistant Cursor, Copilot, Gemini CLI, ChatGPT, local models Paste PORTABLE.md /stalebrainlabs/stalebrain/blob/main/PORTABLE.md into the chat, or drop it in your repo and say "run the stale-brain protocol in PORTABLE.md". It is fully self-contained and degrades gracefully: an assistant with no tools asks you to paste command output batched into one block , and one with no file access prints the diffs for you to apply. Always-on tripwire optional, any agent Add one line to your always-loaded memory file CLAUDE.md, AGENTS.md, or rules : If an instruction in this file contradicts observed reality, say so in one line ⚡ stale-brain instead of silently complying, and suggest a stale-brain audit. Verification is mechanical: glob, grep, and read-only git. No embeddings, no server, no database, no network. Nothing leaves your machine, and nothing gets executed: scripts are verified by their definition scripts block, Makefile, CI , never by running them. Agents keep "ignoring the rules"? Half the time the rules are unfollowable. They name paths that moved, scripts that were renamed, package managers that were swapped out in March. An agent fed contradictory memory doesn't get 90% right; it gets confidently wrong, every session, at a token cost you pay every session. | Capability | How | |---|---| | Claim extraction | Every sentence becomes a typed claim: PATH, SCRIPT, SYMBOL, DEP, FACT, OWNER, CONVENTION. Style opinions are skipped, never judged. | | Verification | Per-type recipes against the live repo. A missing path gets git archaeology to find the rename and the new destination. A wrong owner gets checked against CODEOWNERS and git shortlog. | | Confidence decay | Per-type half-lives paths 30d, conventions 120d . Past its half-life a fact is re-verified or downgraded to a hypothesis. | | Provenance stamps | < -- stale-brain: verified 2026-07-31 -- , invisible in rendered markdown, greppable forever. Stamps make re-audits incremental. | | Contradiction evidence | Never "this looks wrong". Always "wrong since a1b2c3d, here's the diff". | | Cross-file conflicts | CLAUDE.md says yarn, .cursorrules says npm: flagged even when nobody knows which is right. | | Token meter | What your memory costs per session, and what share of it is actively misleading the model. | | Mid-task tripwire | When the agent notices an instruction contradicting reality mid-task, it says so in one line instead of silently complying. | | Approve-only fixes | Every verdict is explained; every edit waits for your yes. Non-interactive runs apply nothing. | | Agent | Files | |---|---| | Claude Code | CLAUDE.md root and nested , CLAUDE.local.md, .claude/ / .md | | Codex / cross-tool | AGENTS.md root and nested | | Cursor | .cursorrules, .cursor/rules/ / .mdc | | GitHub Copilot | .github/copilot-instructions.md, .github/instructions/ .instructions.md | | Gemini CLI | GEMINI.md | | Windsurf | .windsurfrules, .windsurf/rules/ | | Cline | .clinerules file or directory | | Roo Code | .roo/rules/ | | Aider | CONVENTIONS.md when referenced from .aider.conf.yml | | Zed | .rules | | Amazon Q | .amazonq/rules/ | | JetBrains Junie | .junie/guidelines.md | | OpenHands | .openhands/microagents/ .md | Human docs README, CONTRIBUTING, docs/ are out of scope. Lockfiles, manifests, and CI configs are evidence, not memory: they're what claims get checked against. Four verdicts. Every claim lands in exactly one: | Verdict | Meaning | |---|---| | 🟢 CONFIRMED | Evidence checks out today. Gets a dated stamp on apply. | | 🟡 STALE | Re-verification came back inconclusive owner inactive, convention eroding . Downgraded to "as of , X was true". | | 🔴 CONTRADICTED | Affirmative evidence against, with the specific commits cited and a corrected rewrite. | | ⚪ UNVERIFIABLE | No mechanical check exists. Says so explicitly. Never guesses. | Health = confirmed + 0.5 × stale / confirmed + stale + contradicted × 100. A valid stamp counts as a confirmation; unverifiable claims are excluded because not knowing is not the same as being wrong. The output system is a feature, not a byproduct. Reports follow CALM rules chunked to 5 findings per block, verdict first, zero narration rendered with Pulse graph primitives: an append-only ticker that streams audit progress one line at a time, and terminal graphs for health, token cost, and trend. Every evidence line carries a direct or inferred provenance tag; why C7 reprints any finding as its full evidence chain; brief collapses the report to 10 lines; files shows per-file health strips; a decay line names the next half-life expiry; and applied fixes end in a one-line GAIN summary health, misleading tokens, and recovered tokens, before → after . All of it is plain Unicode with a complete ASCII fallback, built from scratch, zero dependencies. Full spec in references/output-format.md /stalebrainlabs/stalebrain/blob/main/references/output-format.md . Each audit is recorded in .stale-brain/audit-YYYY-MM-DD.md , which feeds the trend graph on the next run. Feature checks verified 2026-07-31 against each project's published docs and source. ✓ shipped, ~ partial, ✗ absent. | stalebrain | | |---| ctxlint https://github.com/YawLabs/ctxlint agents-lint https://github.com/giacomo/agents-lint AgentLinter https://agentlinter.com/ claude-memory-health https://github.com/alexknowshtml/claude-memory-health If one row matters most, it's the stamps: without provenance, every other tool re-audits everything from zero and can't tell you how old a "fact" is. With them, stalebrain is a trust model you can grep. SKILL.md the protocol Claude Code entry point PORTABLE.md self-contained any-agent version references/ memory-sources.md where every agent keeps its brain claim-types.md taxonomy, half-lives, verification recipes output-format.md CALM rules, Pulse graphs, token meter, report + audit formats src/stalebrain/ the installer CLI stalebrain install / portable / path assets/ hero and demo art pyproject.toml uv / pipx / pip packaging The skill doesn't trigger. Type /stale-brain directly, or use the phrases in the trigger description: "audit my agent memory", "verify my CLAUDE.md", "my agent ignores the rules". Skill activation is description-matched and inexact everywhere. A verdict looks wrong. Every verdict cites its evidence: a lockfile, a scripts block, a commit hash. Check the citation first; if the evidence is right and the verdict is still wrong, that's a bug worth reporting. It flagged something I want to keep. Nothing is applied without your approval of the specific diff. Decline the fix; the claim stays as it was. Style preferences are never flagged at all OPINION claims are skipped . The token numbers look off. They're file bytes ÷ 4, labeled as estimates ±20% for English text . The signal is the ratio of misleading to total, not the absolute count. Output symbols look garbled. Say "ascii". Every symbol has a plain-text fallback with the same line structure. My repo is a shallow clone. Drift detection needs history. stalebrain notices shallow clones and re-verifies instead of trusting an empty drift pass, but full history gives better citations. MIT. See LICENSE /stalebrainlabs/stalebrain/blob/main/LICENSE . All content is original work, written from scratch.