---
title: "Stream run events (SSE)"
method: GET
path: "/v1/runs/{run_id}/events"
tags: ["runs"]
---

# Stream run events (SSE)

`GET /v1/runs/{run_id}/events`

Scope: `runs:read`. Free. An ordered at-least-once Server-Sent Events stream. Successfully persisted frames have an effectively unbounded replay window and resume with `Last-Event-ID` or `?after=<seq>`. Intermediate appends are best-effort and can be absent after a transient storage failure; terminal status/done are transactionally admitted with Agent Run terminal state. The edge may rotate a connection after 300 seconds, so reconnect with the last sequence and reconcile authoritative state with GET /v1/runs/{run_id}.

A stream can close on any of THREE terminal frames, not just `done`:
- `event: done` — the run reached a terminal state and the sentinel was delivered.
- `event: timeout` with `data: {"reason":"stream_max_duration"}` — the server hit its own stream wall-clock ceiling. The RUN may still be going. Reconnect with the last sequence; do not treat this as a run outcome.
- `event: error` with `data: {"code":..., "message":...}` — the event read failed. Reconnect with `Last-Event-ID` to replay from the cursor.

Each frame's `data:` field carries only the event's inner payload; `seq` is on the `id:` line and the event type is the event name. To read a finished run's whole trajectory as plain JSON, use GET /v1/runs/{run_id}/log instead.

## Query parameters

- `after` integer

## Headers

- `Last-Event-ID` integer

## Response `200`

SSE stream (text/event-stream).

## Other responses

- `400` — Invalid request body or parameters.
- `401` — Missing, invalid, or revoked API key. Pass `X-API-Key: sk-coasty-live-...` (or test).
- `403` — API key lacks the required scope or tier-feature is unavailable on the caller's plan.
- `404` — Resource not found in this key's namespace.
- `409` — The resource state conflicts with this operation.
- `413` — The request body exceeds the endpoint limit.
- `422` — The JSON shape is valid but one or more values violate the endpoint contract.
- `429` — Rate or concurrency limit exceeded.
- `500` — Unexpected server error. Retry with exponential backoff.
- `502` — An upstream dependency returned an invalid response.
- `503` — A required service is temporarily unavailable.
- `504` — An upstream dependency timed out.

---

[API](https://skmtc.net/coasty/apis/coasty-public-api.md) · [All operations](https://skmtc.net/coasty/apis/coasty-public-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/coasty/coasty-public-api/revisions/f50d93b0d8a1/schema)