Pre-alphabeing built

Dig up what you built with AI.

COAL keeps a record of your work outside any one tool: what you meant to do, what got made, and what comes next. It is open source, it lives in a folder on your machine, and any AI tool that supports MCP (the Model Context Protocol) can read it.

Enter the mine Read the spec

We are building it in the open. The implementation is written in Go and builds from source; there is no release yet. It runs the demo from a recorded Claude Code session, from capture to the resume line, and has been run against one live session. The first release captures from Claude Code only, and anything else you add by hand.

Level 1−20 m

It's in one of those chats. Somewhere.

You use Claude, ChatGPT, Cursor and Claude Code in the same week. Each one makes things: an HTML page, a script, a plan, a decision. Each one forgets what you were doing when the session ends. The only index is which conversation it was in.

Level 2−90 m

Three things, kept outside any one tool.

For each thing you are working on, COAL keeps one record, called an Intent Manifest.

intent

The intent, in your words

The first thing you asked for becomes the summary. You search for it later the way you said it, not the way a model paraphrased it.

artifacts[]

The artifacts

Pages, scripts and docs, copied in and addressed by their SHA-256 hash, so the record survives a moved file or a deleted chat. By default that means HTML, Markdown, Python and TypeScript; the list is a setting. Each one notes which tool made it.

state

The state

When you last touched it, the next step, and the questions still open. This is what lets the next session start where the last one stopped.

Level 3−180 m

It writes itself while you work.

Claude Code runs hooks at fixed points in a session. COAL listens to them. You do not fill in anything.

Claude Code is the only tool in the first release. Cursor, Codex CLI and Gemini CLI have hooks too, so each can get a small adapter that feeds the same capture contract.

Pages made in claude.ai or ChatGPT are not captured. In the first release you add them by hand with coal add. Importing Claude Code session logs exists as a first version, coal import claude-code. Importing chat exports is the Phase 2 item.

SessionStart
COAL finds the record for this folder and puts the next step on screen.
PostToolUse
Claude writes budget.html. COAL registers it as an artifact. On the first write it creates the record, using your first message as the summary, and drops a small .coal marker in the project.
Stop
After each turn, COAL takes a quick note and gets out of the way.
SessionEnd
A job is queued and the hook returns at once. If Claude did not record the next step during the session, COAL extracts a short summary and next step from the transcript when the queue is next folded: at your next session start, or within seconds if coal serve is running.

Level 4−300 m

Find that thing you built, from any tool.

Any tool connected to the COAL MCP server can search the record and open what it finds. Ask Cursor for the budget tracker you built in Claude Code and you get the same record. coal find does the same from the terminal.

terminalMockup

$ coal find "budget"
019a3f2c  Household budget tracker as a single HTML page  active  6d ago  1 artifact
          Household budget tracker as a single HTML page

any MCP clientMockup

Find the budget thing I built

called coal_find({ query: "budget" })

called coal_get({ id: "019a3f2c" })

Household budget tracker as a single HTML page

activeyour words1 artifact · budget.html

Last activity 1 Nov · Claude Code

Next: Add CSV export and a category edit dialog

Here it is. You last worked on it in Claude Code on 1 November and left off at CSV export. Want me to open it?

Level 5−450 m

Pick up where you left off.

Open a session in a folder that has a record and the next step is on screen before you type.

~/projects/budgetMockup

~/projects/budget $ coal resume

◆ COAL: Household budget tracker as a single HTML page. Next: Add CSV export and a category edit dialog. 1 open question.

● You left off at CSV export. The page renders categories and a transaction form, with no persistence yet. One open question: keep data in localStorage, or let you pick a JSON file?

  Continue with CSV export?

`coal resume`

Finds the record for this folder and starts Claude Code with the resume as the first turn. You type nothing and it opens with where you left off.

Plain `claude`

The COAL line with the next step shows before you type. Whatever you say first, the reply opens by offering to continue from it.

Level 6−650 m

The format is the product.

Each record is one JSON file in ~/.coal/manifests/. You can read it with cat. Any tool can write one. The Intent Manifest schema is open, and the v0.1 draft is published at coalmine.io/schema/intent-manifest/0.1.json.

~/.coal/manifests/019a3f2c….json (excerpt)

{
  "$schema": "https://coalmine.io/schema/intent-manifest/0.1.json",
  "version": "0.1",
  "id": "019a3f2c-8e4b-7d31-9a5c-2f6b1c8d4e70",
  "rev": 3,
  "intent": {
    "summary": "Household budget tracker as a single HTML page",
    "source": "user"
  },
  "status": "active",
  "artifacts": [{
    "hash": "sha256:9f86d0…0a08",
    "title": "budget.html",
    "type": "html",
    "producer": { "tool": "claude-code" },
    "versions": [{ "hash": "sha256:9f86d0…0a08", "createdAt": "2026-11-01T02:14:09Z", "producer": { "tool": "claude-code" } }]
  }],
  "state": {
    "lastActivityAt": "2026-11-01T02:41:33Z",
    "nextStep": "Add CSV export and a category edit dialog",
    "openQuestions": ["localStorage or a JSON file?"]
  },
  "provenance": { "tool": "claude-code", "model": "claude-opus-5-5" },
  "contexts": [{ "kind": "path", "key": "/Users/you/projects/budget" }]
}

intent.sourceWho wrote the summary: you or a model. Search ranks your own words first.
artifacts[].hashSHA-256 of the copy in ~/.coal/artifacts/, matching the latest entry in versions[], which keeps every version COAL recorded. A version whose body was not copied (possible secret, too large) keeps a salted blind hash and a skipped reason instead. The original path is kept too, but it can go stale.
state.nextStepThe line every resume starts from.
contexts[]Where this work lives. When a project has no .coal marker, SessionStart uses it to find the record.
provenanceWhich tool and model wrote the record. It never stores tokens or secrets.

Level 7−800 m

Nothing about it locks you in.

Every manifest is a JSON file and every stored artifact is a plain copy of the original, all under ~/.coal/. None of it needs COAL to open.

Local first. Everything lives in ~/.coal/. No account. The only server is the daemon on your own machine.
Files are the truth. Plain JSON is the record. The search index is SQLite and can be deleted and rebuilt from the files.
Your words first. The summary is what you typed. A model can suggest a better one, but it never overwrites yours.
No telemetry. No network calls you did not set up yourself. The daemon listens on 127.0.0.1 only.
Never deletes. Remove means move to the trash folder. The one exception is coal purge, which deletes an artifact body that holds a secret after you confirm; the record stays. When git is installed, every CLI or MCP change to a record is a commit, and the hooks' writes are committed in batches by the daemon or by the next coal command.
Open, all of it. Apache 2.0: the schema, the library, the CLI and every adapter. No paid tier.

Level 8−950 m

Four phases. Each starts only after a retro on the last.

Phase 1 is the MVP, about six weeks, and it ends with a week of real use. If COAL does not get used unprompted at least five times that week, the project stops there and the spec stays open.

Phase 1

Record

Capture from Claude Code, find from any MCP tool, resume in the next session.

In progress

Phase 2

Reach

Import from chat exports (a first version of import from Claude Code session logs already exists), adapters for Cursor and Codex, semantic search with a local model.

Phase 3

Attention

Surface the right record at the right time, by rules you can read and edit.

Later

Phase 4

Portability

Spec v1.0 with a second implementer, encrypted sync between your devices.

Later

The seam−1000 m

We are building it. Come join us.

The implementation is written in Go. It began as a collaborator's proof of concept and was adopted as the Phase 1 implementation on 2026-11-07 (ADR-018). It builds from source with Go 1.27, runs the demo from a recorded Claude Code session, and has been run against one live Claude Code session: capture through the real hooks, find from the CLI and over MCP, the resume line at session start, and coal resume. There is no release yet, the web UI builds only with a package that is not published yet, and the bugs found so far are open issues. Read the spec, build it, and open an issue for anything that is wrong or unclear.

There are 9 diamonds in the walls on the way down.

Read the spec Build and run it How to help

Dig up what you built with AI.

It's in one of those chats. Somewhere.

Three things, kept outside any one tool.

The intent, in your words

The artifacts

The state

It writes itself while you work.

Find that thing you built, from any tool.

Pick up where you left off.

coal resume

Plain claude

The format is the product.

Nothing about it locks you in.

Four phases. Each starts only after a retro on the last.

Record

Reach

Attention

Portability

We are building it. Come join us.

`coal resume`

Plain `claude`