{state_callback_url}
Consumer-hosted URL supplied as state_callback on upload. Secure Redact periodically POSTs media progress/status updates to it.
Channel address
Parameters
state_callback_url— The state_callback URL provided when the media was uploaded.
Operations
Messages
application/jsonAbout AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.
Browse every event-driven channel on the APIs.io network or compare with the broader Agent Skill and MCP server surfaces of the same providers.
Work with this as data
Every channel here is available over the APIs.io API and to AI agents over MCP.
MCP server
One button, every client — Claude, Cursor, VS Code and the rest.
https://apis.io/mcp
Tools for event channels
4 MCP tools reach this
find_channelsBrowse and filter every channel in the catalog.apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.resolveTurn a domain, URL or GitHub org into the provider it belongs to.find_cohortsEvery scored population of providers in the catalog.
Call it yourself
curl for this page
curl "https://apis.io/api/v1/channels/state-callback-url"curl "https://apis.io/api/v1/channels?limit=25"Discovery needs no key. Ratings and market analysis are Pro.