Longhand

Using Codex too? Share one memory archive between Claude Code and Codex.

Persistent local memory for Claude Code. Every tool call, every file edit, every thinking block from every Claude Code session — stored verbatim on your machine. Searchable, replayable, and recallable by fuzzy natural-language questions. Zero API calls. Zero summaries. Zero decisions made by an AI about what's worth remembering.

Claude Code quietly rotates your session files after a few weeks. Longhand captures them into SQLite before they're gone. Once ingested, your history stays forever — even after the source JSONL files are deleted. Install early; the past you don't capture is unrecoverable.

If you have 20+ Claude Code sessions in ~/.claude/projects/, Longhand can search across every fix, decision, and conversation you've had in ~56ms — without a single API call.

Does it use a lot of tokens? No — every tool is capped by design. A full recall across 100+ sessions returns ~4K tokens. Reading one raw session JSONL costs 10–50× more. See Token budget.

pip install longhand
longhand setup        # ingest history + install hooks + configure MCP
longhand recall "that stripe webhook bug from last week"

Want to kick the tires first? Run longhand demo for a 60-second walkthrough on a fake 3-session sample corpus — your real ~/.claude and ~/.longhand are not touched. The demo seeds a sandboxed store with a Stripe-webhook bug + Supabase auth migration + downstream 401 fix, then runs cross-session recall and project-status so you can see what the output looks like before committing.

pip install longhand
longhand demo         # sandboxed; cleans up afterwards (pass --keep to explore)

Upgrading to 1.0.0? This is the release that closes the deprecation window 0.13 opened. Everything removed here has been warning since 0.13.0:

• Four CLI aliases are gone: patterns → recall "<topic>", recap → status --days N, continue → status --session <prefix>, reanalyze → analyze --all.
• The reconcile MCP tool now defaults to a dry run. If you have an agent loop that relied on the implicit heal, pass fix=true explicitly. Dry runs tell you so in the payload.
• Six retired MCP tools left the listing (19 → 13) but still answer forever with a migration note — retired names live in users' own CLAUDE.md files and must never hard-fail.
• New: COMPATIBILITY.md states what 1.x guarantees and what it doesn't.

Your database needs nothing. Migrations are automatic and a 0.11+ store opens on any later 1.x — that's Promise 2, and there's a real 0.11-schema fixture in the test suite proving it.

Upgrading to 0.13.0? Nothing breaks — that release opened the v1.0 deprecation window, so every old name kept working while pointing at its replacement:

• status is now the single resume command: bare status = recent digest (was recap), status <project> unchanged, status --session <prefix> = session tail (was continue). The old commands still run and print a pointer; they're removed at v1.0.
• Six MCP tools folded into six survivors with identical parameters (search_in_context → search + context_events, get_episode → find_episodes + episode_id, etc. — full table in the CHANGELOG). The retired names still answer, prefixed with a migration note.
• Hooks can no longer exit nonzero — failures become breadcrumbs in ~/.longhand/logs/ and two new doctor rows (Hook errors, Transcript format) keep them visible.
• "Today"/"yesterday" recall windows now follow your local calendar day instead of UTC's; rankings may shift once if you're not in UTC.
• Windows users: this release fixes a serious bug where the ingest-lock liveness check could terminate other longhand processes.
• New: LONGHAND_DATA_DIR relocates the store for the CLI, hooks, and MCP server in one move; status --json / doctor --json for scripting.

Upgrading to 0.9.0? Live ingestion captures sessions in flight, plan history is preserved as first-class data, and an optional reconciler job keeps the index honest in the background:

• New longhand ingest-live command runs from Claude Code's Stop hook to tail the active transcript between assistant turns. Sessions show up in recall while you're still working, not after they end.
• New longhand plans list command and list_plans MCP tool surface every Write/Edit to ~/.claude/plans/*.md across your entire history. Plans are now extracted as their own entity alongside episodes.
• New longhand schedule install-reconciler installs an optional launchd job that runs reconcile --fix periodically — catches anything the live and post-session hooks missed without you ever thinking about it.
• The Stop hook coexists with the existing SessionEnd hook: live tails the transcript as it grows; SessionEnd does the full analysis pass when the session closes.

Upgrading to 0.8.1? Staleness signals now propagate everywhere they belong, and reconcile is an MCP tool — Claude can self-heal the index from inside a session:

• search and list_sessions now wrap the response with stale: true + stale_reason when the project they're scoped to has on-disk transcripts not yet ingested. Pre-v0.8.1 these returned clean-looking empty results (same silent-failure shape recall_project_status was built to catch — just one layer up).
• New reconcile MCP tool wraps longhand reconcile --fix. After a staleness banner fires, Claude calls reconcile directly instead of asking the user to run a CLI command.
• list_sessions default limit raised from 20 to 50 — active days routinely cross 5+ projects across 5+ sessions; the old default truncated reviews silently.

Upgrading from 0.7.x or earlier? Cleaner recall narratives, plus a real bug-finding test layer underneath (from 0.8.0):

• Pre-v0.8 _compose_fix_summary prepended a literal "Intent:" label to half of all extracted episodes (49% of the reference corpus). The label leaked into every recall narrative for those episodes. Migration v4 strips it from existing rows on first store open — no command needed.
• Diff content in fix_summary now truncates at whitespace boundaries with a visible …, instead of landing mid-token (phoneNum', family?:', strin'). Forward-only.
• Narrative footer "Other matches" lines now include the session id so you can drill in.
• New canary harness (tests/fixtures/corpus/) anchors regression tests to real shipped bugs. New recall validator (scripts/recall_diff.py) snapshots and diffs ranking results against your live corpus — catches regressions pytest can't see.

pip install --upgrade longhand
longhand recall "..."   # migration runs transparently on first open

If you're also coming from 0.5.x, run longhand reconcile --fix once to re-attribute multi-project sessions per the v0.6 inference improvements (cd-into-project sessions now attribute to the project where most work happened, not the first-event cwd). If you're on 0.5.8 or earlier, chain them: longhand reconcile --fix && longhand analyze --all. Both are idempotent.

Large history? (>1 GB of ~/.claude/projects) Expect the first-time backfill to take 10–30 minutes on an M-class Mac — most of that wall time is the embedding model running on all your cores (which is why you'll see triple-digit CPU%; that's ONNX doing its job, not a hang). To get a working store faster, use the fast-path:

longhand setup --skip-analysis   # SQLite only; works in ~1 min for multi-GB corpora
longhand analyze --all           # fill in episodes + vectors whenever, safe to background

Exact-text search, timelines, file history, and commit lookup all work after --skip-analysis. Semantic recall needs the analyze --all pass to complete. Typical throughput on an M-class Mac is ~1–2 sessions/sec for full analysis.

Status: v1.2.0 — stable, daily-driver tested, security-audited (zero critical findings), on PyPI, available as a Claude Code plugin. Validated against 433 real Claude Code sessions across 37 inferred projects (measured 2026-08-12). 588 unit tests passing.

Full docs: Longhand Wiki — getting started, CLI reference, MCP tools reference, architecture, and troubleshooting.

---

The Inversion

Everyone is solving AI memory by making the context window bigger. 1M tokens. 2M tokens. Context-infinite. The whole industry is racing in the same direction: make the model carry more state.

Longhand goes the other direction. The model doesn't need to carry the memory. The disk does.

	Bigger context windows	Longhand
Where it lives	Rented from a model provider	A SQLite file + ChromaDB on your laptop
Cost per query	Tokens × dollars	Zero
Privacy	Goes through someone else's servers	Never leaves your machine
Speed	Seconds to minutes for large contexts	~56ms search · ~1.4s full recall
Loss	Attention degrades in the middle of long contexts	Every event from the source file, nothing dropped
Persistence	Dies when the window closes	Lives until you delete the file
Across model versions	Doesn't transfer	Same data, any model
Offline	No	Yes
Scales with	Provider's pricing	Your hard drive

The "memory crisis" in AI was an artificial constraint. Storage is solved. SQLite is from 2000. ChromaDB is two years old. Both run on a laptop. Longhand bypasses the crisis by ignoring it — your past sessions are already on disk, written by Claude Code itself, in JSONL files that contain every single event verbatim. Longhand reads those files, indexes them locally, and gives you semantic recall over your entire history without ever sending a token through someone else's API.

Local. Complete. Yours.

Storage footprint: ~5GB for a heavy power user (430+ sessions, 195k+ events, months of daily Opus usage across 37 inferred projects). Typical users: 200–400MB. Once Claude Code rotates the source files off disk, Longhand isn't a duplicate — it's the only copy.

---

Platform support

Python 3.10 – 3.14 are all fully supported and gated in CI — every release must pass the full suite on all five before it can merge.

Longhand pins chromadb<1.0 for every Python version, not just 3.14. The pin originated with chromadb's newer Rust bindings segfaulting on 3.14 (#4, now closed), and it stays until a 1.x chromadb is verified across the whole matrix.

Windows: CI-tested, best-effort. A windows-latest × py3.12 leg runs on every PR and has gone green on every run since v0.13.0, but it is non-blocking and covers one Python version on GitHub's runners. That is honest evidence, not a support tier — Linux and macOS are the tested platforms. Windows bugs are welcome as issues; they just aren't release-blocking.

Codex Desktop and Codex CLI threads are captured into the same archive from 1.1.0 — see Works with Codex.

---

Compatibility

Longhand 1.0 makes five promises, each backed by an enforcement artifact in the repo. The full text is in COMPATIBILITY.md; the short version:

1. Stable surface — CLI and MCP frozen through 1.x. Removals only at a major version, and only after warning for one full minor.
2. Forward data compat — a database written by 0.11+ opens on any later 1.x. Migrations are automatic, one-time, never renumbered. Older code refuses a newer database loudly rather than operating blind.
3. Hook guarantees — hooks never raise, never touch the network, never block your prompt.
4. Upstream drift is never silent — unknown transcript entries are preserved, surfaced in doctor, and regression-gated.
5. Honest metrics — counts reflect real signals, and doctor never recommends a remedy that cannot work.

Deprecation policy: anything slated for removal warns for at least one full minor release first, and the warning names its replacement. Retired MCP tool names are the one thing that never goes away — they leave the tool listing but keep answering forever with a migration note, because those names live in users' own CLAUDE.md files.

---

Longhand vs claude-mem

thedotmack/claude-mem is the most popular Claude Code memory tool on GitHub (55k+ stars). It's a good tool. It is also solving the memory problem in the opposite direction from Longhand, and the difference is worth understanding before you pick one.

	claude-mem	Longhand
What's stored	AI-generated summaries / "observations"	Verbatim events from the raw JSONL
Who decides what's kept	An LLM, at write time	Nobody — everything is kept
Compression	Semantic (lossy, by design)	None (lossless)
API calls per session	One or more (calls Claude to summarize)	Zero
Thinking blocks	Typically folded into summaries	First-class, stored verbatim
Deterministic replay	No — summaries can't reconstruct file state	Yes — every diff kept and replayable
Model portability	Tied to the summarizer's output	Same data works across any model, forever
Runtime	TypeScript, Bun, HTTP worker on :37777	Python, no server
License	AGPL-3.0	MIT

The philosophical split: claude-mem asks an AI what was important and keeps that. Longhand keeps the actual bytes and lets you decide later. If you trust a model's judgment about its own past, claude-mem's approach is cheaper at query time (pre-summarized) and easier on storage. If you've ever been burned by a summary that dropped the thing that turned out to matter, Longhand is the tool that never throws anything away.

Both can coexist on the same machine — they operate on the same JSONL files without interfering.

---

The Principles

Longhand is built on a handful of principles. If you disagree with them, you probably want a different tool.

1. Information doesn't disappear — it moves.

When data goes "missing" it's almost never actually gone. It got compressed, summarized, filed somewhere else, or renamed. Find the raw source and the truth is still there waiting. Claude Code already writes every session to disk as JSONL. That file is the raw source. Longhand just reads it.

2. Summarization is a lossy decision disguised as a convenience.

Most AI memory systems read a conversation and ask the AI to write down "what mattered." The AI is now the gatekeeper of its own memory, and the AI has incentives — brevity, confidence, coherence — that aren't the same as truth. You end up with a story about what happened instead of what happened.

Longhand never summarizes. It stores the complete record and lets you query it.

3. The raw record is cheap. Acting like it isn't wastes it.

A full Claude Code JSONL file is kilobytes to low megabytes. A year of daily sessions is hundreds of megabytes. That is nothing on modern hardware. There is no engineering reason to throw the data away. Summary-based memory isn't saving space — it's giving away information that was free.

4. The thinking is the most valuable part.

When Claude produces a thinking block, that's the reasoning behind the decision — usually invisible to the user, almost always more useful than the final answer. Summary-based memory throws thinking blocks away because they're "internal." Longhand treats them as first-class events. "What was I thinking when I chose to use a conditional update?" pulls the verbatim thinking block that contains the answer.

5. A fix you can't reproduce is a fix you didn't keep.

If you fixed a bug in March, the state of that file when the bug was fixed is a fact. Longhand reconstructs it deterministically by applying every edit in sequence from the session JSONL. No guessing, no AI inference, just literal application of the diffs. You can see the exact state of any file at any point in any past session.

6. Memory should be proactive, not just searchable.

A searchable archive is useful but passive. Real memory answers fuzzy questions. "A couple months ago I was building a game that kept breaking, then you fixed it — bring that fix forward." Longhand parses the time phrase, matches the project, finds the problem→fix episode, and returns the diff. You don't have to know the session ID. You just have to remember that it happened.

7. Deterministic beats clever.

Everything in Longhand's analysis is rules-based. Regex error detection. Hash-based project IDs. Forward-walking episode extraction. No LLMs in the core pipeline. That means fast (< 200ms recall queries), reproducible (same input → same output), and fully local (no API keys, no cloud). An LLM layer could go on top later, but the foundation runs on laws, not on a model's opinion.

8. Local or nothing.

Your Claude Code history is yours. It goes into a SQLite file and a ChromaDB directory in ~/.longhand/. No telemetry. No sync. No account. If your laptop is offline, Longhand works. If Anthropic goes down, Longhand works. If you delete the directory, it's gone.

One boring exception, disclosed in full: the interactive CLI checks pypi.org for a newer Longhand version at most once a day. That request carries nothing but itself — no telemetry, no identifiers, nothing about your corpus — and a newer version just shows up as a dim one-line hint and a doctor row. It never runs from hooks or the MCP server, never blocks a command, and LONGHAND_NO_UPDATE_CHECK=1 turns it off entirely. "Zero API calls" means what it always meant: no LLM or cloud service ever touches your data.

---

What It Actually Does

When you use Claude Code, every session writes a JSONL file to ~/.claude/projects/<project>/<session-id>.jsonl. That file contains every message, every tool call, every thinking block, every file edit with full before/after content, and a millisecond-precise timestamp for each event.

Longhand reads those files. Then it gives you:

• Semantic search across every event you've ever generated
• Filterable search — by tool, file, session, project, time range, event type — all filters combinable
• Tool call archaeology — "show me every Bash command I ran in March that touched Supabase"
• File history across sessions — every edit to a specific file, chronologically, across all your sessions
• Session replay — reconstruct any file's state at any point in any past session
• Reasoning retrieval — query Claude's verbatim thinking blocks
• Timeline view — chronological playback with pagination (offset, tail, summary-only scan mode)
• Fuzzy recall — natural-language questions about past work ("that race condition fix from last week")
• Project inference — automatic detection of which projects you've worked on, with categories and aliases
• Episode extraction — automatic detection of problem→fix sequences in your sessions
• Conversation segments — topic-level clustering (stories, design discussions, debugging, planning) so recall finds the why, not just the what
• Git-aware project recall — ask "where did we leave off on X" and get recent commits, unresolved issues, last session outcome in one call
• Git commit extraction — structured extraction of every git commit, push, merge, checkout from sessions, linked to episodes
• MCP server — 13 tools that let Claude query Longhand directly during live conversations
• Auto-ingest hook — drops into Claude Code's SessionEnd hook so new sessions are indexed automatically
• Live ingestion — optional Stop hook tails the active transcript between turns so in-flight sessions show up in recall immediately
• Plan history — every Write/Edit to ~/.claude/plans/*.md is captured as a first-class entity, queryable via longhand plans list and the list_plans MCP tool
• Secret redaction (opt-in) — longhand config --set redact.enabled=true masks secret-shaped strings (API keys, tokens, JWTs, DB passwords) at ingest before they reach the index; longhand redact --apply retroactively masks data ingested earlier
• Background reconciler — optional launchd job (longhand schedule install-reconciler) keeps the index honest without manual reconcile --fix runs
• Context injection — UserPromptSubmit hook auto-injects relevant past context before Claude sees your message (configurable threshold and size cap)
• Configurable — longhand config to tune injection relevance, token budget, and behavior without editing code

---

Install

pip install longhand
longhand setup

That's it. longhand setup backfills your existing Claude Code history, installs the hooks that keep it updated automatically, registers Longhand as an MCP server for Claude Code, and verifies everything works. About two minutes the first time, zero maintenance after that.

To upgrade later: pip install -U longhand.

Developer install (from source)

git clone https://github.com/Wynelson94/longhand.git
cd longhand
pip install -e .
longhand setup

longhand ingest                       # ingest all your existing Claude Code history
longhand analyze --all                # run analysis (projects, outcomes, episodes, segments)
longhand hook install                 # wires both SessionEnd and Stop hooks
longhand ingest-live                  # live-tail the active transcript (Stop hook calls this)
longhand prompt-hook install          # (optional) auto-inject past context into new prompts
longhand mcp install                  # let Claude Code call Longhand as MCP tools
longhand schedule install-reconciler  # (optional) launchd job to run reconcile --fix periodically
longhand config                       # view/tune hook behavior (relevance threshold, injection size)
longhand doctor                       # verify everything is wired up

---

Quick Start