# Add a timeline entry

`POST https://evohub.io/api/v1/incidents/{id}/timeline`

Part of the [On-Call API](https://docs-dev.evohub.io/oncall.md) reference · operationId `addIncidentTimelineEntry`.

Adds an entry to the incident's timeline. When the incident is published to a
status page, the entry is posted there as an update as well.

**Permission (API-key scope):** `oncall:incident:write`.

## Authorization

Any one of:

- `bearerAuth` (oncall:incident:write)
- `apiKeyHeader` (oncall:incident:write)

Where:

- `bearerAuth`: HTTP Bearer — An EvoHub API key (`evohub_…`) as a bearer token.
- `apiKeyHeader`: API key in the header `X-API-Key` — An EvoHub API key (`evohub_…`).

## Path parameters

- `id` (string, required, example `2e7f9a1b-3c4d-4e5f-8a9b-0c1d2e3f4a5b`): The incident's id.

## Request body (required)

Content type: `application/json`

Type: `MessageBody`

- `message` (string, required, min length 1)

## Responses

### 201 — The entry.

Content type: `application/json`

Type: `object`

- `data` (IncidentTimelineEntry, required)
  - `id` (string)
  - `incident_id` (string)
  - `author_id` (string)
  - `status` (string): The incident's status when the entry was written.
  - `message` (string)
  - `created_at` (string (date-time))
- `success` (boolean, required, value `true`)

### 400 — The body is not JSON (`INVALID_BODY`) or `message` is empty (`VALIDATION_FAILED`).

Content type: `application/json`

Type: `ValidationError`

- `error` (object, required)
  - `code` (string, required, value `VALIDATION_FAILED`)
  - `message` (string, required)
  - `details` (array of object, required)
    - `field` (string)
    - `message` (string)

### 401 — No API key was sent, or it is unknown, revoked or expired (`UNAUTHORIZED`).

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required): Machine-readable code. Branch on this.
  - `message` (string, required): Human-readable explanation.

### 403 — The key lacks the scope this endpoint needs (`FORBIDDEN`).

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required): Machine-readable code. Branch on this.
  - `message` (string, required): Human-readable explanation.

### 404 — No incident with this id in your organization (`NOT_FOUND`).

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required): Machine-readable code. Branch on this.
  - `message` (string, required): Human-readable explanation.

### 429 — Too many requests (`RATE_LIMITED`). Wait `Retry-After` seconds.

Headers:

- `Retry-After` (integer): Seconds to wait.

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required): Machine-readable code. Branch on this.
  - `message` (string, required): Human-readable explanation.

### 500 — Something went wrong on EvoHub's side (`INTERNAL_ERROR`). Retry later.

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required): Machine-readable code. Branch on this.
  - `message` (string, required): Human-readable explanation.

## Example request

```bash
curl -X POST 'https://evohub.io/api/v1/incidents/2e7f9a1b-3c4d-4e5f-8a9b-0c1d2e3f4a5b/timeline' \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer <TOKEN>' \
  -d '{
  "message": "Rolled back payments-api to v2.14.3."
}'
```