# Recipe: onboard into a project

A copy-paste prompt: your agent reads a new repo, checks what onecell already knows, and writes a project primer with the three things to read first.

> [!info]
> **For:** a developer joining a project that is new to them. **When:** day one, or any time you pick up an unfamiliar repo. **Takes:** about five minutes of agent time. **You get:** a draft project primer in onecell, a few remembered facts every later agent session starts with, and the three things to read or ask first.

## The prompt

Open your agent inside the repo, copy the prompt, and replace the parts in `<angle brackets>`.

```text
Onboard me to <repo> using onecell. Save the result to <cell> (default: my Inbox).

1. Check onecell first. Call list_cells, then search for the project and repo
   name, and list_decisions for any cell that covers it. Open only the hits you
   will use with get_document, and cite them as cell · heading · passage.
   Don't repeat what onecell already holds; link to it.

2. Read the repo without changing anything: the README, CONTRIBUTING,
   AGENTS.md or CLAUDE.md, package manifests, entry points, CI config,
   `git log --oneline -30` and the open branches.

3. Draft a document titled "Project primer: <repo>" with create_document
   (dry run first). Include:
   - What it is, in three sentences, and a stats block of headline numbers
   - A mermaid diagram of the main components and how requests flow
   - Run it locally: a steps block with the exact commands
   - Conventions: a table of rules, each with the file it comes from
   - Recent activity: a timeline of notable merges
   - Decisions already made (cited), and open questions as a checklist
   - Where things live: bookmarks

4. Call recall for <repo>, then remember 3 to 5 durable facts with entity
   "<repo>": how to run the tests, how it deploys, who owns it. If a fact
   contradicts one onecell already holds, tell me instead of replacing it.

5. Reply with the document link and the three things I should read or ask
   first. Keep the document a draft; don't publish or share it unless I ask.
```

## What your agent does

1. Checks what onecell already knows
   list_cells, search and list_decisions find earlier notes and accepted decisions about the project, so the primer links to them instead of starting from nothing.
2. Reads the repo, read-only
   The README, contribution and agent guides, manifests, CI config and recent git history. Nothing in the repo changes.
3. Writes the primer as a draft
   create_document, dry run first, into the cell you named or your private Inbox.
4. Remembers the durable facts
   recall first, then remember a few facts under the repo's name, so the next agent session, in any tool, starts informed. Conflicts come back to you rather than being overwritten.
5. Tells you where to start
   A link to the primer and the three things to read or ask first.

## What you get

A primer for Tally, a made-up invoicing app. Note the open questions at the end: they are the part to take to the team.

<!-- onecell:block {"type":"embed","documentId":"c87e394e-4e0d-4f4d-bdab-7755b7cfec01"} -->
[Sample project primer: the Tally repo, for a new engineer](https://onecell.io/p/sample-project-primer-tally)

## Variations

<details>
<summary>Joining a team that already uses onecell</summary>

Point it at the team's hive: set `<cell>` to the hive and add “Search the hive before reading the repo, and treat what's there as the source of truth.” Publish the primer only after a teammate has read it, so the next new joiner finds a checked version.

</details>

<details>
<summary>Onboarding someone else</summary>

A lead runs the recipe before the new hire starts, then adds: “Write it for a new engineer named `<name>`, and end with a first-week checklist.” Share the cell with them, as a viewer to start.

</details>

<details>
<summary>Briefing a new agent instead of a person</summary>

Ask for a short agent brief instead of a primer: the conventions and the commands only. Then have it add a pointer to the primer's cell in the repo's `AGENTS.md` or `CLAUDE.md`, so every agent that opens the repo knows where to look.

</details>

## Tips

- Keep the primer a draft until someone who knows the project has read it.
- Run it again after a big release: it updates the timeline and catches docs that have drifted.
- The open questions are the valuable part. Take them to the team instead of guessing.
- To keep up week to week, follow it with [Recipe: repo snapshot](https://onecell.io/help/recipes/recipe-repo-snapshot).

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Part of [onecell recipes](https://onecell.io/help/recipes): copy-paste prompts for using onecell in your work.