> **Building with AI coding agents?** Install the authstack plugin with one command. This equips your agent with accurate Scalekit implementation patterns.
>
> **Recommended** (the `-y` flags skip prompts, so the command runs without an interactive terminal):
> ```bash
> npx -y @scalekit-inc/cli setup -y
> ```
>
> Global:
> ```bash
> npm install -g @scalekit-inc/cli
> scalekit setup -y
> ```
>
> Supports Claude Code, Cursor, GitHub Copilot, Codex + skills for other Agent Skills-compatible agents in `~/.agents/skills`.
> Skills: integrate-agentkit, implement-saaskit, add-mcp-oauth, implement-sso, implement-scim.
> [Full setup guide](https://docs.scalekit.com/dev-kit/build-with-ai/)

---

# Set a signing secret (beta)

`PUT /api/v1/connections/{connection_id}/trigger-ingress/signing-secret`

This endpoint is in beta. Its request and response may change.

Saves the secret the app signs its webhook events with, copied from your app's settings at the provider, so Scalekit can verify each event. Until a secret is set, the webhook URL doesn't accept events. If a secret is already set, a new one starts a rotation: both are accepted until you [confirm the rotation](https://docs.scalekit.com/agentkit/reference/triggers/confirm-a-signing-secret-rotation/), or for at most 24 hours. Read the secret from your server's secrets, never from code. For an app that sends no signature of its own, [generate a secret](https://docs.scalekit.com/agentkit/reference/triggers/generate-a-signing-secret/) instead.

**Path parameters**

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `connection_id` | string | Yes | ID of the connection, in this environment. Up to 64 characters. |

**Request body**

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `signing_secret` | string | Yes | The secret the provider signs its events with, copied from the provider's app configuration. For Slack this is the Signing Secret under Basic Information, not an API token. Between 8 and 4096 characters. For Gong, the RSA public key shown by 'Show public key'. Never returned by any endpoint and never written to a log. |

**Response (200)**

| Name | Type | Description |
| --- | --- | --- |
| `connection_id` | string | ID of the connection this webhook URL belongs to. |
| `id` | string | Unique identifier of the connection's webhook endpoint. |
| `masked_signing_secret` | string | The stored secret with all but its last four characters replaced, or every character replaced for a secret of 8 characters or fewer. Empty when none is configured. Enough to compare against the secret the provider's app configuration shows, and never enough to sign with. |
| `previous_signing_secret_expires_at` | string | When the previous secret stops being accepted even if the rotation is never confirmed: 24 hours after the rotation started. Absent when no rotation is in progress. |
| `rotation_in_progress` | boolean | Whether the previous signing secret is still accepted alongside the current one. True from the moment a different secret replaces a stored one until the rotation is confirmed, or until previous_signing_secret_expires_at passes. |
| `signing_secret_configured` | boolean | Whether a signing secret is stored. While false, every event sent to the URL is answered with 503 so the provider retries it, and the provider's own URL verification fails. |
| `signing_secret_rotation_id` | string | Identifies the latest signing-secret rotation; it increases by one each time a rotation starts. Zero when none has ever started. Pass this value to [Confirm a signing secret rotation](https://docs.scalekit.com/agentkit/reference/triggers/confirm-a-signing-secret-rotation/) to confirm this specific rotation. A value naming a rotation that a newer one has since replaced is refused rather than confirming the wrong rotation. |
| `url` | string | The URL to paste into the provider's app configuration as the event destination. It is built on your environment's domain, using its custom domain when one is set, and ends in a random token unique to this connection, so treat it as confidential. Returned whether or not a signing secret has been set. The URL accepts request bodies up to 1 MB and answers a larger one with 413. Until a signing secret is set it answers events with 503, so the provider retries them; an event that fails signature verification is answered with 400. |

**Errors**

- `400`: Invalid request, nothing written - connection_id is not a valid connection ID; signing_secret is shorter than 8 characters once leading and trailing whitespace is removed, or longer than 4096 characters; the connection's provider sends no signature of its own, so its secret is generated by Scalekit rather than set (error_code TRIGGER_SIGNING_SECRET_GENERATED_ONLY; call [Generate a signing secret](https://docs.scalekit.com/agentkit/reference/triggers/generate-a-signing-secret/) instead); or the provider's webhook trigger definitions are temporarily unavailable (error_code TRIGGER_INGRESS_DEFINITIONS_UNAVAILABLE)
- `404`: Not found - no webhook URL has been created for this connection yet (error_code TRIGGER_INGRESS_ENDPOINT_NOT_CREATED; call [Create a webhook URL](https://docs.scalekit.com/agentkit/reference/triggers/create-a-webhook-url/) first), the connection does not exist in this environment (error_code RESOURCE_NOT_FOUND), or Triggers isn't turned on for your environment (error_code RESOURCE_NOT_FOUND)
- `409`: Conflict - a rotation is already in progress. Confirm it with [Confirm a signing secret rotation](https://docs.scalekit.com/agentkit/reference/triggers/confirm-a-signing-secret-rotation/), or wait for the previous secret's expiry, before setting another secret
- `500`: Internal error - the signing secret could not be stored; retry the request

**Request**

```bash
curl -sS -X PUT \
  "$SCALEKIT_ENVIRONMENT_URL/api/v1/connections/conn_133400101014997214/trigger-ingress/signing-secret" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "signing_secret": "<Signing Secret from Basic Information in your Slack app>"
  }'
```

**Response**

```json
{
  "id": "tie_149528599802678310",
  "connection_id": "conn_133400101014997214",
  "url": "https://your-env.scalekit.dev/triggers/v1/q7Rk2mVx9TbL4nWc8YpZ3s",
  "signing_secret_configured": true,
  "masked_signing_secret": "****************************a4f9",
  "rotation_in_progress": true,
  "signing_secret_rotation_id": "1",
  "previous_signing_secret_expires_at": "2026-10-29T09:30:00Z"
}
```

**Python SDK:** `scalekit_client.actions.triggers.set_signing_secret`

Store the signing secret the provider signs its events with. The first call stores it. A call with a different secret starts a rotation: both secrets are accepted until `confirm_signing_secret_rotation` or for 24 hours. Not retried on `UNAVAILABLE`, because a retry could advance the rotation.

```python
scalekit_client.actions.triggers.set_signing_secret(
    connection_id: str,
    signing_secret: str,
) -> TriggerIngressEndpoint
```

Example:

```python
import os

result = scalekit_client.actions.triggers.set_signing_secret(
    connection_id="conn_133400101014997214",
    signing_secret=os.environ["SLACK_SIGNING_SECRET"],
)
```

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `connection_id` | `str` | Yes | The connection (`conn_...`). |
| `signing_secret` | `str` | Yes | The secret from the provider's app configuration (8-4096 characters; surrounding whitespace is trimmed by the server). |

Returns `TriggerIngressEndpoint`: The endpoint, with `masked_signing_secret` and rotation state.


Part of [Triggers](https://docs.scalekit.com/agentkit/reference/triggers/) in the [AgentKit API reference](https://docs.scalekit.com/agentkit/reference/). Authentication: https://docs.scalekit.com/agentkit/reference/authentication.md. Errors and rate limits: https://docs.scalekit.com/agentkit/reference/errors.md. Pagination: https://docs.scalekit.com/agentkit/reference/pagination.md


---

## More Scalekit documentation

| Resource | What it contains | When to use it |
|----------|-----------------|----------------|
| [/llms.txt](/llms.txt) | Structured index with routing hints per product area | Start here — find which documentation set covers your topic before loading full content |
| [/llms-full.txt](/llms-full.txt) | Complete documentation for all Scalekit products in one file | Use when you need exhaustive context across multiple products or when the topic spans several areas |
| [sitemap-0.xml](https://docs.scalekit.com/sitemap-0.xml) | Full URL list of every documentation page | Use to discover specific page URLs you can fetch for targeted, page-level answers |