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

# Attaching tools, knowledge and channels

> Add or remove one tool, one knowledge node or one channel without resending the whole list.

An agent holds three lists: the **tools** it may call, the **knowledge** it may search, and the **channels** it answers on. Each one can be replaced whole, or changed one item at a time.

**Use the single-item routes.** Adding one tool by sending the whole array forces you to read, merge and write — and two clients doing that at the same time lose one of the changes. Here the server does the merge.

## The routes

|           | Replace the list                | Add one                                       | Remove one                                      |
| --------- | ------------------------------- | --------------------------------------------- | ----------------------------------------------- |
| Tools     | `PUT /v1/agents/{id}/tools`     | `POST /v1/agents/{id}/tools/{toolId}`         | `DELETE /v1/agents/{id}/tools/{toolId}`         |
| Knowledge | `PUT /v1/agents/{id}/knowledge` | `POST /v1/agents/{id}/knowledge/{nodeId}`     | `DELETE /v1/agents/{id}/knowledge/{nodeId}`     |
| Channels  | `PUT /v1/agents/{id}/channels`  | `POST /v1/agents/{id}/channels/{channelType}` | `DELETE /v1/agents/{id}/channels/{channelType}` |

All of them need `agents:write` and all of them return the whole agent, so you can see the result without a second read.

## Example

<CodeGroup>
  ```bash curl theme={"system"}
  TOKEN="kbai_pk_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
  AGENT=6650a1b2c3d4e5f6a7b8c9d0

  # Give it a tool
  curl -X POST https://api.keebai.com/v1/agents/$AGENT/tools/6650cccc3333dddd4444eeee \
    -H "Authorization: Bearer $TOKEN"

  # Enable a channel
  curl -X POST https://api.keebai.com/v1/agents/$AGENT/channels/whatsapp \
    -H "Authorization: Bearer $TOKEN"

  # Replace the knowledge list in one call
  curl -X PUT https://api.keebai.com/v1/agents/$AGENT/knowledge \
    -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
    -d '{"knowledge_node_ids": ["6650dddd4444eeee5555ffff"]}'
  ```

  ```js JavaScript theme={"system"}
  const agent = "6650a1b2c3d4e5f6a7b8c9d0";
  const headers = { Authorization: `Bearer ${process.env.KEEBAI_API_TOKEN}` };

  await fetch(`https://api.keebai.com/v1/agents/${agent}/tools/${toolId}`, {
    method: "POST",
    headers,
  });

  await fetch(`https://api.keebai.com/v1/agents/${agent}/channels/whatsapp`, {
    method: "POST",
    headers,
  });
  ```
</CodeGroup>

## Errors worth knowing

### 404 `AGENT_TOOL_NOT_FOUND`

No tool in this company with that id. It is rejected rather than stored: an agent silently ignores a tool it cannot find, so saving it would be a `200` with no effect.

### 404 `CHANNEL_TYPE_NOT_FOUND`

The channel type is not in [the catalogue](/dev/endpoints/prompt-types-list). The error lists the valid ones.

### 404 `AGENT_NOT_FOUND`

No agent with that id in the token's company and project.

## Operational notes

* **Adding something that is already there succeeds.** These are idempotent: the end state is what you asked for.
* **Removing unassigns, it does not delete.** A detached tool still exists in the company and a detached node still exists in the knowledge base.
* **Enabling a channel on the agent is only half of it.** The account also has to be connected to the company. One half without the other answers nothing, and it is the most common cause of "the agent is not replying".
* **Concurrent writes to the same agent still race.** The platform replaces the whole array on every save, so the server-side merge removes your round trip, not the race. Serialise writes per agent.