HTTP Headers

Every HTTP header an API can speak — 302 headers assembled from the IANA HTTP Field Name Registry, 119,030 published specification files across 26,641 providers, and the regulations that reach the wire. What each header is for, how to use it, and the standard, guidance and law behind it.

HTTP Headers publishes 1 API contract indexed on the APIs.io network. Tagged areas include API Design, HTTP Headers, and Standards.

📡 Profile data on GitHub
3.2/100 minimal Agent 0/100 human only Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →
1 published contract
API DesignHTTP HeadersStandards

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0
Composite quality — 3.2/100 · minimal
Contract Quality 1.3 / 21
Developer Ergonomics 0.0 / 17
Access Clarity 0.0 / 17
Operational Transparency 0.0 / 11
Contract Governance 0.0 / 10
Discoverability 3.3 / 9
Regulatory Posture 0.0 / 15
Agent readiness — 0/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Well-Known Document 0 / 5
Pagination 5 / 5
Distinct Operations 3 / 3
Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Show this score on your site. Kin Score badge preview for HTTP Headers It updates itself when the score changes. Paste this where you link to your API docs: 
<a href="https://apis.io/providers/headers/"><img src="https://apis.io/badge/headers/card.svg" alt="HTTP Headers on APIs.io — Kin Score by API Evangelist"></a>
Other styles, a README pill and a shields.io endpoint are on the badge page.
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Agent readiness — checks not met, largest first (exact, from this profile):
  • Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
  • MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
  • Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
  • Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
  • Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
  • A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
13 more unmet checks in the Agent Readiness table above.
Kin Score — facets with the most composite points still available (weight × headroom):
Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/headers/apis.yml: open an issue on github.com/api-evangelist/headers to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Resources

Other 1

Properties that don't map to a standard resource type

Standards
Standards

Source (apis.yml)

apis.yml Raw ↑ 
aid: headers
name: HTTP Headers
description: Every HTTP header an API can speak — 302 headers assembled from the IANA HTTP Field Name Registry, 119,030 published
  specification files across 26,641 providers, and the regulations that reach the wire. What each header is for, how to use
  it, and the standard, guidance and law behind it.
type: Index
image: https://kinlane-productions.s3.amazonaws.com/apis-json/apis-json-logo.jpg
tags:
- API Design
- HTTP Headers
- Standards
url: https://raw.githubusercontent.com/api-evangelist/headers/refs/heads/main/apis.yml
created: '2024-11-11'
modified: '2026-03-16'
specificationVersion: '0.19'
apis: []
common:
- type: Standards
  url: https://github.com/api-evangelist/headers
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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