# Create join

URL: https://docs.hanzo.ai/docs/openapi/provider/post-provider-slack-join

> Joins every public channel in the caller org's workspace.

`POST /v1/provider/slack/join`

> [Provider →](https://docs.hanzo.ai/docs/openapi/provider) · [All API references →](https://docs.hanzo.ai/docs/openapi) · [Get started →](https://docs.hanzo.ai/docs/guides)

|               |                                               |
| ------------- | --------------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/provider/slack/join` |
| **Method**    | `POST`                                        |
| **Operation** | `post_provider_slack_join`                    |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`        |

Joins every public channel in the caller org's workspace.

Org admin, because it changes what the whole workspace sees: after it the agent
is a member of every public room and answers in all of them.

## Request

The document declares no body for `POST /v1/provider/slack/join`. The handler is typed in cloud but its shape is not yet emitted, so the fields are not listed here — ask MCP's `describe` for `post_provider_slack_join`, which answers from the running route.

## Response

| Status    | Body                  | Meaning |
| --------- | --------------------- | ------- |
| `200`     | provider.slackJoinOut | ok      |
| `default` | problem-details       | refused |

`200` body — 7 fields.

| Field              | In   | Type                    | Always | Description                                                                                                            |
| ------------------ | ---- | ----------------------- | ------ | ---------------------------------------------------------------------------------------------------------------------- |
| `already`          | body | integer (int64)         | —      | Already counts the channels it was a member of before, kept apart from Joined because only one of the two is a change. |
| `failed`           | body | provider.joinFailure\[] | —      | Failed is per-channel, so one refusal does not hide the rest of the walk.                                              |
| `failed[].channel` | body | string                  | —      | Channel is Slack's id for the room that refused.                                                                       |
| `failed[].error`   | body | string                  | —      | Error is Slack's own code, carried through unchanged.                                                                  |
| `failed[].name`    | body | string                  | —      | Name is that room's human name, so the operator does not have to look the id up.                                       |
| `joined`           | body | string\[]               | —      | Joined names the channels this run walked into — the change it made.                                                   |
| `listed`           | body | integer (int64)         | —      | Listed is every public, unarchived channel the workspace has.                                                          |

Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo provider slack join
```

**SDK**

**.ts**

```ts
import { Configuration, ProviderApi } from 'hanzoai';

const api = new ProviderApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postProviderSlackJoin();
```

**.py**

```python
from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import ProviderApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = ProviderApi(client).post_provider_slack_join()
```

**.go**

```go
cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.ProviderAPI.PostProviderSlackJoin(context.Background()).Execute()
if err != nil {
	return err
}
```

**.rs**

```rust
use hanzo_client::apis::{configuration::Configuration, provider_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = provider_api::post_provider_slack_join(&cfg, Default::default()).await?;
```

**.java**

```java
import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.ProviderApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new ProviderApi(client).postProviderSlackJoin();
```

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/provider/slack/join \
  -H "Authorization: Bearer $HANZO_API_KEY"
```

**MCP**

MCP reaches **provider** through the `provider` tool, which names its 38 operations with its own verbs — this one among them, under a name only MCP declares. `describe` explains any of them:

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "describe",
         "arguments": {
           "op": "list_connections"
         }
       }
     }'
```

---

[Provider API](https://docs.hanzo.ai/docs/openapi/provider) · [All Hanzo APIs](https://docs.hanzo.ai/docs/openapi) · [Interactive reference](https://docs.hanzo.ai/docs/openapi/reference)