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id

de facto — unregistered request 2 spellings

Declared by 39 providers across 846 published specification files in the APIs.io network.

What this header is for, and how to use it →

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.

Spelled 2 ways

HTTP field names are case-insensitive (RFC 9110 §5.1), so every spelling below is the same header on the wire. A contract is not the wire: generated clients key off the string, and a developer reading two of these sees two different headers.

idId

Providers declaring it (39)

8x8 ankorstore apache-couchdb arduino canonical cedarai certifyos cisco-ise continuous-delivery-foundation form3 gloo integration-os isometric jp-morgan-chase kiteworks lianlian-global liveramp microsoft-power-pages mtn-group nhs-digital nuclei ocean-security onerail oracle ory outdoorsy physna picus-security qliksense replicate return-path simplismart snappt solo-io sparkyfitness squarespace tesslio treadio virustotal

Explore

All headers Tracing & Correlation 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.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for http headers

3 MCP tools reach this

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.

All 92 tools →

Call it yourself

curl for this page

Search the catalog

curl "https://apis.io/api/v1/search?q=id&limit=10"

Everything under a tag

curl "https://apis.io/api/v1/tags/id"

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