---
title: "Opens a Server-Sent Events stream for real-time client flag updates."
method: GET
path: "/v1/client/stream"
tags: ["Client SDK"]
---

# Opens a Server-Sent Events stream for real-time client flag updates.

`GET /v1/client/stream`

## Request

- Base URL: `https://eval.featureflip.io`
- URL: `https://eval.featureflip.io/v1/client/stream`
- Auth: API key in header `Authorization`

Auth is passed as an `?authorization=csk_...` query parameter because a browser
EventSource cannot set headers. User context is passed as `?context=base64json`.

## Query parameters

- `context` string

## Response `200`

SSE stream opened successfully.

## Other responses

- `401`: Client SDK key is missing or invalid.
- `503`: Flag configuration is temporarily unavailable; retry after the interval in `Retry-After`.

---

[API](https://skmtc.dev/featureflip/apis/featureflip-evaluation-api.md) · [All operations](https://skmtc.dev/featureflip/apis/featureflip-evaluation-api/llms.txt) · [OpenAPI document](https://skmtc.dev/featureflip/apis/featureflip-evaluation-api/revisions/1f5311d7fc25?raw)