> For the complete documentation index, see [llms.txt](https://docs.getblock.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getblock.io/api-reference/avail/websocket-subscriptions-api.md).

# Websocket Subscriptions API

WebSocket API reference for Avail subscriptions. Receive real-time updates for extrinsics, block heads, runtime versions, and storage changes.

Pub-sub methods served over the Avail WebSocket interface only. Each opens a stream: send the subscribe request, receive a subscription id, then receive a notification per update. Cancel with the matching unsubscribe method.

## Subscriptions

<table data-search="false"><thead><tr><th>Method</th><th>Description</th></tr></thead><tbody><tr><td><code>chain_subscribeNewHeads</code></td><td>Stream new block headers</td></tr><tr><td><code>chain_subscribeFinalizedHeads</code></td><td>Stream finalized block headers</td></tr><tr><td><code>state_subscribeStorage</code></td><td>Stream storage changes for keys</td></tr><tr><td><code>author_submitAndWatchExtrinsic</code></td><td>Submit an extrinsic and stream its status</td></tr><tr><td><code>chain_subscribeAllHeads</code></td><td>Stream all block headers, including forks</td></tr><tr><td><code>chain_subscribeRuntimeVersion</code></td><td>Stream runtime version changes</td></tr><tr><td><code>grandpa_subscribeJustifications</code></td><td>Stream GRANDPA finality justifications</td></tr><tr><td><code>beefy_subscribeJustifications</code></td><td>Stream BEEFY justifications</td></tr><tr><td><code>transactionWatch_v1_submitAndWatch</code></td><td>Submit and watch a transaction using the new specification</td></tr></tbody></table>

## Support

* Support: <support@getblock.io>