Preference-Applied
IANA permanent
response
RFC 7240
Declared by 4 providers across 18 published specification files in the APIs.io network.
A count here is providers whose published contract declares this header — not
providers who send it. Response headers set at the edge rarely appear in an OpenAPI at all, so a low
number can measure documentation practice rather than deployment.
The registry
| Status | permanent |
|---|---|
| Reference | RFC 7240: Prefer Header for HTTP |
Providers declaring it (4)
anyapi cdk-global insforge microsoft-azure
Explore
All headers Async & Long-Running Guidance on headers.apievangelist.com
Work with this as data
Every header here is available over the APIs.io API and to AI agents over MCP. HTTP Headers is not yet its own endpoint on the v1 API. Reach it through catalog search and the tag graph, or the MCP server.