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

# GET /v8/missions/{runId}/events — Stream Mission Events

> GET /v8/missions/{runId}/events streams Server-Sent Events for a Praxa mission. The stream closes automatically when the mission reaches a terminal state.

The `GET /v8/missions/{runId}/events` endpoint opens a durable, resumable Server-Sent Events (SSE) stream for a mission. As the agent executes each step, the gateway emits a typed event that you can consume in real time. You can reconnect at any point in the stream's history by sending the `Last-Event-ID` header — the gateway maintains a bounded replay window so you never miss events across brief network interruptions. The stream closes automatically once the mission reaches a terminal state (`succeeded`, `failed`, or `cancelled`).

## Endpoint

```
GET /v8/missions/{runId}/events
```

**Required scope:** `missions:read`

**Response content type:** `text/event-stream`

**Required headers:**

| Header          | Description                                                         |
| --------------- | ------------------------------------------------------------------- |
| `Authorization` | `Bearer <access_token>` — short-lived Ed25519 delegated OAuth token |
| `Accept`        | `text/event-stream`                                                 |

**Optional headers:**

| Header          | Description                                                                                                                                                                                        |
| --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Last-Event-ID` | Resume the stream from a specific event. The value must be an event `id` previously received from this stream. If the ID is outside the bounded replay window, the gateway returns `409 Conflict`. |

***

## Path Parameters

<ParamField path="runId" type="string (UUID)" required>
  The unique run identifier returned when you created the mission via `POST /v8/missions`. Must be a valid UUID v7.
</ParamField>

***

## SSE Event Format

Each event conforms to the [WHATWG EventSource specification](https://html.spec.whatwg.org/multipage/server-sent-events.html). Events carry three lines:

```text Example SSE event theme={null}
id: evt_01
event: mission.step.completed
data: {"stepId":"step_1","result":{"summary":"Loaded calendar data"}}
```

| Field   | Description                                                                                                |
| ------- | ---------------------------------------------------------------------------------------------------------- |
| `id`    | Opaque, stable cursor for this event. Pass this as `Last-Event-ID` to resume the stream after a reconnect. |
| `event` | Event type string. See the table below for all possible values.                                            |
| `data`  | JSON-encoded payload specific to the event type.                                                           |

***

## Event Types

| Event type               | Emitted when                                                                                                                              |
| ------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------- |
| `mission.started`        | The agent begins executing the mission for the first time                                                                                 |
| `mission.step.started`   | The agent begins a new reasoning or tool-call step                                                                                        |
| `mission.step.completed` | A step finishes successfully; payload includes the step result summary                                                                    |
| `mission.completed`      | The mission reached the `succeeded` terminal state; stream closes after this event                                                        |
| `mission.failed`         | The mission reached the `failed` terminal state (budget exceeded, policy error, or unrecoverable failure); stream closes after this event |
| `mission.cancelled`      | The mission reached the `cancelled` terminal state (explicit cancellation); stream closes after this event                                |

<Warning>
  Events that arrive after a `mission.completed`, `mission.failed`, or `mission.cancelled` event are informational trailing events only. Do not assume the stream will emit additional state-changing events once a terminal event is received.
</Warning>

***

## Example: Consuming with curl

<CodeGroup>
  ```bash cURL theme={null}
  curl -N https://your-gateway.example/v8/missions/018e2f3a-7c14-7000-b1e2-4d3f8a20c911/events \
    -H "Authorization: Bearer $PRAXA_ACCESS_TOKEN" \
    -H "Accept: text/event-stream"
  ```

  ```bash cURL — resume from last event theme={null}
  curl -N https://your-gateway.example/v8/missions/018e2f3a-7c14-7000-b1e2-4d3f8a20c911/events \
    -H "Authorization: Bearer $PRAXA_ACCESS_TOKEN" \
    -H "Accept: text/event-stream" \
    -H "Last-Event-ID: evt_04"
  ```

  ```typescript TypeScript SDK theme={null}
  import { PraxaClient } from "@praxa/sdk";

  const client = new PraxaClient({ accessToken: process.env.PRAXA_ACCESS_TOKEN });

  const runId = "018e2f3a-7c14-7000-b1e2-4d3f8a20c911";

  for await (const event of client.missionEvents(runId)) {
    console.log(event.event, event.data);

    if (
      event.event === "mission.completed" ||
      event.event === "mission.failed" ||
      event.event === "mission.cancelled"
    ) {
      break; // Terminal state reached — generator closes automatically
    }
  }
  ```
</CodeGroup>

***

## SDK Equivalent

```typescript theme={null}
for await (const event of client.missionEvents(runId)) {
  // event: AuraSseEvent
  // event.id    — cursor for Last-Event-ID resumption
  // event.event — event type string
  // event.data  — parsed JSON payload
}
```

| Parameter | Type     | Description                              |
| --------- | -------- | ---------------------------------------- |
| `runId`   | `string` | UUID of the mission to stream events for |

**Returns:** `AsyncGenerator<AuraSseEvent>`

<Note>
  The SDK's `missionEvents` async generator closes automatically when the stream reaches a terminal event (`mission.completed`, `mission.failed`, or `mission.cancelled`). You do not need to call `.return()` or wrap the loop in a `try/finally` block for normal termination. For early exits, use `break` inside your `for await` loop and the generator will clean up the underlying HTTP connection.
</Note>

***

## Error Responses

| HTTP Status        | Typical cause                                                                                        |
| ------------------ | ---------------------------------------------------------------------------------------------------- |
| `401 Unauthorized` | Missing or expired `Authorization` bearer token                                                      |
| `403 Forbidden`    | Token lacks `missions:read` scope                                                                    |
| `404 Not Found`    | No mission exists for the given `runId` under your principal                                         |
| `409 Conflict`     | The `Last-Event-ID` cursor is outside the bounded durable replay window; re-fetch from the beginning |