--- description: Use the Realtime SFU HTTPS API from your backend to manage sessions, tracks, DataChannels, and WebSocket media adapters. title: Connection API image: https://developers.cloudflare.com/realtime/sfu/api/og.png?v=e297f2705ac92808 --- [Skip to content](#main-content) > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/realtime/llms.txt > Use this file to discover all available pages before exploring further. # Connection API Last updated Sep 22, 2026|Copy as Markdown| [View as Markdown](https://developers.cloudflare.com/realtime/sfu/api/index.md)| [Agent setup](https://developers.cloudflare.com/agent-setup/) Use the Connection API to manage a Realtime SFU application's media resources. Your backend sends authenticated HTTPS requests, while endpoints exchange media and DataChannels with the SFU over WebRTC. Base URL: ```txt https://rtc.live.cloudflare.com/v1 ``` Send `Authorization: Bearer ` and `Content-Type: application/json`. Keep the App Secret on trusted backend infrastructure. Endpoint authentication and resource authorization belong to your application. [Download the full OpenAPI schema](https://developers.cloudflare.com/realtime/static/realtime-api-2024-05-21.yaml) for request and response fields. To implement a connection, follow the [browser and backend recipes](https://developers.cloudflare.com/realtime/sfu/get-started/connection-patterns/) for publication, reception, messages, or media with controls. Use this reference to look up operations and fields. ## Create an application Create an SFU app in the dashboard or through the [Cloudflare account API](https://developers.cloudflare.com/api/resources/calls/subresources/sfu/methods/create/). App creation uses your Cloudflare account authorization. The Connection API uses the resulting SFU App ID and App Secret. The [quickstart](https://developers.cloudflare.com/realtime/sfu/get-started/) shows this setup with a Worker backend. ## Session and track operations The paths in this table are relative to the base URL: | Operation | Method and path | | --- | --- | | Create a session | `POST /apps/{appId}/sessions/new` | | Publish or subscribe to tracks | `POST /apps/{appId}/sessions/{sessionId}/tracks/new` | | Update tracks | `PUT /apps/{appId}/sessions/{sessionId}/tracks/update` | | Submit a renegotiation answer | `PUT /apps/{appId}/sessions/{sessionId}/renegotiate` | | Close tracks | `PUT /apps/{appId}/sessions/{sessionId}/tracks/close` | | Read session information | `GET /apps/{appId}/sessions/{sessionId}` | Refer to [sessions and tracks](https://developers.cloudflare.com/realtime/sfu/concepts/sessions-tracks/) for publication and identifier ownership. ### Correlate session creation The optional `correlationId` query parameter on `sessions/new` is a diagnostic label. Repeating it creates another session. The API cannot look up sessions by this label. Retain the returned `sessionId`, and follow [recovery guidance](https://developers.cloudflare.com/realtime/sfu/concepts/negotiation/#retry-and-reconnect) if the response is lost. ### Inspect a session Call `GET /apps/{appId}/sessions/{sessionId}` to inspect the session's media tracks and DataChannels. The response identifies media by `mid` and channels by their allocated `id`. For a remote resource, `sessionId` identifies its publisher: ```json { "tracks": [ { "location": "local", "mid": "0", "trackName": "camera", "status": "inactive" } ], "dataChannels": [ { "location": "remote", "sessionId": "", "dataChannelName": "controls", "id": 2, "status": "active" } ] } ``` Interpret the resource's `status` as follows: | Status | Media track | DataChannel | | --- | --- | --- | | `active` | Has not closed or become unavailable. | Open. | | `inactive` | Closed or unavailable. | No longer connecting or open. | | `initializing` | Not applicable. | Still connecting. | A media track marked `active` does not prove that packets are arriving or playing. Use [endpoint statistics](https://developers.cloudflare.com/realtime/sfu/observability/#inspect-browser-media-statistics) to check delivery. Forced closure can leave a track listed as `inactive`. The response contains resource state, not SDP or request history. Pending requests can still change it, even when the resource lists are empty. Follow [retry and reconnect guidance](https://developers.cloudflare.com/realtime/sfu/concepts/negotiation/#retry-and-reconnect) before resuming mutations. ## DataChannel operations These operations act on the same session and negotiation state as its media tracks: | Operation | Method and path | | --- | --- | | Establish transport | `POST /apps/{appId}/sessions/{sessionId}/datachannels/establish` | | Publish or subscribe to channels | `POST /apps/{appId}/sessions/{sessionId}/datachannels/new` | | Update subscription flags | `PUT /apps/{appId}/sessions/{sessionId}/datachannels/update` | | Close channels | `PUT /apps/{appId}/sessions/{sessionId}/datachannels/close` | Refer to [DataChannels](https://developers.cloudflare.com/realtime/sfu/features/datachannels/) for negotiated IDs, reliability, readiness, and reply access. ## WebSocket adapter operations Create adapters to ingest external audio or stream existing audio/video publications to WebSocket endpoints: | Operation | Method and path | | --- | --- | | Create adapters | `POST /apps/{appId}/adapters/websocket/new` | | Close adapters | `POST /apps/{appId}/adapters/websocket/close` | The [WebSocket adapter reference](https://developers.cloudflare.com/realtime/sfu/features/media-transport-adapters/websocket-adapter/) covers formats, request limits, partial success, reconnect, and close behavior. ## Batch resource operations Track and DataChannel create, update, and close operations accept multiple entries in their `tracks` or `dataChannels` array. For example, publish camera and microphone tracks together, or request several publications in one receiving-session call. Each batch targets the session in the request URL. For `tracks/new` and `datachannels/new`, keep every entry `local` or every entry `remote`. A remote batch can reference different publishing sessions. Follow the [operation's limits](https://developers.cloudflare.com/realtime/sfu/platform/limits/#api-and-resource-limits) when choosing its size. WebSocket adapter creation and closure accept one to four entries per request. ## Handle responses and negotiation Check the HTTP status, top-level errors, and every per-track or per-channel result. Public errors use `errorCode` and `errorDescription`. Preserve successful allocations from partially successful requests. Look up the code and its next action in [Error codes](https://developers.cloudflare.com/realtime/sfu/observability/error-codes/). Complete any required SDP exchange before starting the next mutation on that session. Other sessions can proceed independently. [Connection patterns](https://developers.cloudflare.com/realtime/sfu/get-started/connection-patterns/) gives the request sequences, including how to answer an SFU offer. [Negotiation and session lifecycle](https://developers.cloudflare.com/realtime/sfu/concepts/negotiation/) explains concurrent handlers, uncertain request outcomes, and retries. ## Network connectivity Configure endpoint ICE, STUN, and TURN as part of [connection preparation](https://developers.cloudflare.com/realtime/sfu/get-started/connection-patterns/#network-connectivity). That section also covers connection waits and candidate gathering. ## Learn with an example [Run the video room](https://developers.cloudflare.com/realtime/sfu/get-started/) to follow backend session and track operations. The [DataChannel example ↗︎](https://github.com/cloudflare/realtime-examples/tree/main/echo-datachannels#api-and-lifecycle) shows the same API boundary in a small local Node.js server. Was this helpful? YesNo ## On this page [![](https://developers.cloudflare.com/_astro/logo.te5VL_aD.svg)Docs](https://developers.cloudflare.com/) ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/realtime/sfu/api/#page","headline":"Connection API","description":"Use the Realtime SFU HTTPS API from your backend to manage sessions, tracks, DataChannels, and WebSocket media adapters.","url":"https://developers.cloudflare.com/realtime/sfu/api/","inLanguage":"en","image":"https://developers.cloudflare.com/realtime/sfu/api/og.png?v=e297f2705ac92808","dateModified":"2026-09-22","publisher":{"@type":"Organization","name":"Cloudflare","description":"One platform for your apps, agents, and workforce. 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