--- layout: default ---
Header category

Integrity & Signing

Headers carrying a digest or a signature over the message, so a recipient can prove it arrived as it was sent.

14 headers
91 provider declarations
HeaderProvidersStatus
x-jws-signature 35 de-facto regulated
Signature 33 permanent regulated
Digest 13 obsoleted regulated
Tpp-Signature-Certificate 3 vendor regulated
Content-Digest 3 permanent
Signature-Input 2 permanent
Replay-Nonce 2 permanent
Want-Repr-Digest permanent
Want-Digest obsoleted
Want-Content-Digest permanent
Unencoded-Digest permanent
Repr-Digest permanent
Detached-JWS permanent
Want-Unencoded-Digest permanent

All categories

Authentication Authorization & Scope Caching Conditional Requests & Concurrency Content Negotiation Representation Metadata Connection & Transport CORS Security Policy Privacy & Consent Rate Limiting & Quota Tracing & Correlation Idempotency & Reliability Versioning & Lifecycle Integrity & Signing Async & Long-Running Cost & Metering Agent & Bot Identity

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=integrity&limit=10"
Everything under a tag
curl "https://apis.io/api/v1/tags/integrity"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

A second provider on the same verified email joins the account you already have.