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

# Write Commands

> CLI commands for capturing and updating Chain knowledge.

<Warning>
  **Early access** — [**Join the Product Brain Community**](https://community.productbrain.io).
</Warning>

Open a session before write-heavy work:

```bash theme={null}
pb session start
```

Then capture or update:

```bash theme={null}
pb capture "DEC: chose X because Y"
pb update DEC-123
pb relate DEC-123 belongs_to PROD-6
pb promote DEC-123
```

Close when done:

```bash theme={null}
pb session close
```