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Header category

Rate Limiting & Quota

Headers that tell a caller where it stands against a limit. Documented limits give you the ceiling; these tell you your altitude.

9 headers
857 provider declarations
HeaderProvidersStatus
Retry-After 330 permanent regulated
X-RateLimit-Limit 130 de-facto
X-RateLimit-Remaining 130 de-facto
X-RateLimit-Reset 107 de-facto
RateLimit 36 de-facto
RateLimit-Policy 33 de-facto
RateLimit-Limit 32 de-facto
RateLimit-Remaining 30 de-facto
RateLimit-Reset 29 de-facto

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

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