> ## Documentation Index
> Fetch the complete documentation index at: https://docs.productbrain.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Builder Quickstart

> Get your API key and connect your first agent in a couple of minutes.

## 1. Get your API key

Go to **Settings** in the app. Under API Keys, click **Generate**. You'll get a `pb_...` key and a ready-to-use snippet.

## 2. Copy the quickstart snippet

The modal gives you everything your agent needs in one block:

```
Documentation: https://productbrain.com/docs/llm-guide.md
Base URL: https://productbrain.com/api/v1
API Key: pb_your_key_here
Project ID: your-project-id
```

## 3. Give it to your agent

Paste the snippet into your Claude Code session, Cursor config, or any LLM agent. The agent reads the LLM Guide first, then uses the API to understand your project.

**Claude Code example:**

```
Read the documentation at https://productbrain.com/docs/llm-guide.md
then use the API to understand what I'm building and what to work on next.

Base URL: https://productbrain.com/api/v1
API Key: pb_your_key_here
Project ID: your-project-id
```

## 4. Agent reads the tree

The agent calls `GET /api/v1/nodes?projectId=...` to see your full planning tree, and `GET /api/v1/iterations?projectId=...&current=true` to find the active iteration. It knows what to build and what proof to produce.

## 5. Agent writes back

As the agent works, it updates the tree:

```bash theme={null}
# Mark a job done
curl -X POST "$API_URL/mutate" \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"action": "update", "projectId": "your-project", "nodeId": "job-42", "data": {"status": "done"}}'
```

## 6. You review

Open the Delivery Map in the app. See which jobs the agent has completed, what's still open, and how your bets are progressing across iterations.

## What's next

<CardGroup cols={2}>
  <Card title="API Reference" icon="square-terminal" href="/api-reference/introduction">
    Full endpoint docs, nodes, search, mutations, iterations.
  </Card>

  <Card title="LLM Operations Guide" icon="book" href="https://productbrain.com/docs/llm-guide.md">
    The canonical reference your agent reads. Data model, field rules, all endpoints.
  </Card>
</CardGroup>