cap'n hook
cap'n hook (capn-hook) is a lightweight, local-first memory tool for coding agents. The problem it solves is simple: agents forget everything when a session ends, so they re-explore the same codebase mysteries every time. capn lets an agent save the files that answer a question the moment it figures them out, then recall them with a single command next session — skipping the rediscovery. The clever part is cache-busting: each saved answer is fingerprinted with the sha256 of its backing files, and the moment a file changes or disappears, that memory is automatically deleted. You never get a stale answer. It installs as a SessionStart hook for Claude Code and Codex (no wrapper, no middleware), stores human-readable Markdown entries in a local, gitignored .capn/ directory, and works agent-agnostically via its CLI. In a benchmark across 60 real developer questions on 5 production codebases, agents using capn recalled answers with 77% fewer tokens than cold exploration at equal correctness.
cap'n hook Review 2026: Persistent Memory for Coding Agents That Auto-Expires When Files Change
In-depth review of cap'n hook — a lightweight local memory tool that lets coding agents save answers and recall them across sessions, with automatic cache-busting via sha256 file fingerprints. Claude Code and Codex native, 77% token savings.
💡 9bests Editorial Buying Advice
Why choose cap'n hook: cap'n hook (capn-hook) is a lightweight, local-first memory tool for coding agents. The problem it solves is simple: agents forget everything when a session ends, so they re-explore the same codebase mysteries every time. capn lets an agent save the files that answer a question the moment it figures them out, then recall them with a single command next session — skipping the rediscovery. The clever part is cache-busting: each saved answer is fingerprinted with the sha256 of its backing files, and the moment a file changes or disappears, that memory is automatically deleted. You never get a stale answer. It installs as a SessionStart hook for Claude Code and Codex (no wrapper, no middleware), stores human-readable Markdown entries in a local, gitignored .capn/ directory, and works agent-agnostically via its CLI. In a benchmark across 60 real developer questions on 5 production codebases, agents using capn recalled answers with 77% fewer tokens than cold exploration at equal correctness.
Optimal workflow match: Ideal for teams seeking automated and streamlined AI workflows.
✅ Pros / Key Advantages
- • Saves agents from re-exploring known code
- • Auto cache-bust on file change — no stale answers
- • Zero wrapper: just a SessionStart hook
- • Local-first, gitignored, agent-agnostic CLI
- • 77% token savings in benchmark
❌ Cons / Limitations
- • First run downloads a 300MB–2GB embedding model
- • Memory is local-only, not shared across machines
- • Relies on the model following its hint
- • Official hooks only for Claude Code & Codex
- • Benchmark scope is limited (5 repos)
💰 Pricing Plans & Structure
Free (Open Source, MIT)
Pricing details are gathered from public sources and are subject to change. Please visit the official website for real-time rates and trial terms.
Pricing verified from official public sources · Reviewed by Bill (Lead Editor)
🎯 Who should use cap'n hook
Best suited for users focused on digital productivity and AI automation who value saves agents from re-exploring known code.
⚠️ Who should look elsewhere
Users who require features outside its core scope or cannot accommodate first run downloads a 300mb–2gb embedding model may benefit from exploring alternative tools in this category.
🚀 Common use cases
Autocompleting and refactoring code
Multi-file AI edits
Debugging and test generation
⚖️ Direct Head-to-Head Comparisons
Curated Matchupscap'n hook vs Cursor
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cap'n hook vs GitHub Copilot
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cap'n hook vs Windsurf (Codeium)
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cap'n hook vs Replit Agent
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❓ Frequently asked questions
Is cap'n hook free?
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Pricing for cap'n hook is available on its official site.
What is cap'n hook used for and what are its strengths?
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Key strengths of cap'n hook: Saves agents from re-exploring known code, Auto cache-bust on file change — no stale answers. cap'n hook (capn-hook) is a lightweight, local-first memory tool for coding agents. The problem it solves is simple: agents forget everything when a session ends, so they re-explore the same codebase mysteries every time. capn lets an agent save the files that answer a question the moment it figures them out, then recall them with a single command next session — skipping the rediscovery. The clever part is cache-busting: each saved answer is fingerprinted with the sha256 of its backing files, and the moment a file changes or disappears, that memory is automatically deleted. You never get a stale answer. It installs as a SessionStart hook for Claude Code and Codex (no wrapper, no middleware), stores human-readable Markdown entries in a local, gitignored .capn/ directory, and works agent-agnostically via its CLI. In a benchmark across 60 real developer questions on 5 production codebases, agents using capn recalled answers with 77% fewer tokens than cold exploration at equal correctness.
What is the best alternative to cap'n hook?
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If you're looking for an alternative to cap'n hook, consider Cursor: it stands out for Best AI code editor, Multi-file editing.
How do I choose the right alternative to cap'n hook?
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Selection advice: compare ratings, pricing, and core features within the AI Coding category, then match to your own workflow. See the comparison matrix and Top alternatives list on this page.
🔄 Top Alternatives to cap'n hook
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