API-Security-Auth-Protocol-Reference

Standards, sources, and coverage

Last reviewed: 2026-08-16

This file defines what “comprehensive” means for this repository. The guides cover the listed baselines for HTTP and JSON APIs. A statement is normative only when it is tied to a cited specification using that specification’s requirement language. Otherwise it is labelled Project recommendation.

Scope

Included:

Not covered in depth:

Primary standards

Area Source Status used here Review note
OAuth 2.0 RFC 6749 RFC Base authorization framework. Read with RFC 9700.
OAuth security RFC 9700 Best Current Practice Current security baseline for OAuth 2.0 deployments.
OAuth 2.1 draft-ietf-oauth-v2-1-15 Active Internet-Draft, 2026-03-02 Work in progress, not an RFC. Do not present draft text as a stable RFC requirement.
OAuth bearer tokens RFC 6750 RFC Bearer-token transport and threat considerations.
PKCE RFC 7636 RFC Authorization-code interception protection.
OpenID Connect OpenID Connect Core 1.0 incorporating errata set 2 OpenID Final Specification with errata Standardized end-user authentication and ID Token validation.
SAML 2.0 OASIS SAML 2.0 Technical Overview and conformance requirements OASIS overview and standard Browser SSO, assertions, profiles, and conformance.
JWT RFC 7519 RFC Generic JWT claims are application and profile dependent.
JWT security RFC 8725 Best Current Practice Algorithm verification, explicit typing, and cross-JWT confusion.
JWT access tokens RFC 9068 RFC profile Defines required claims for conforming OAuth JWT access tokens.
Revocation RFC 7009 RFC Token revocation endpoint.
Introspection RFC 7662 RFC Active-state lookup for tokens.
Token exchange RFC 8693 RFC Delegation and impersonation token exchange.
Client authentication RFC 7523, RFC 8705 RFCs private_key_jwt, mutual-TLS client authentication, and certificate-bound tokens.
Resource indicators RFC 8707 RFC Binds an authorization request to a target resource.
DPoP RFC 9449 RFC Application-layer proof of possession.
HTTP message signatures RFC 9421 RFC Standard canonicalization and signature fields. The guide’s HMAC snippet is illustrative and not an RFC 9421 wire example.
PAR RFC 9126 RFC Pushed Authorization Requests.
Authorization server metadata RFC 8414 RFC Authorization-server discovery metadata.
Protected resource metadata RFC 9728 RFC Resource-server metadata and authorization-server locations.
FAPI 2.0 FAPI 2.0 Security Profile OpenID Final Specification, 2025-02-22 High-security OAuth 2.0 profile.
MCP authorization MCP 2025-11-25 authorization Versioned MCP specification Authorization is optional; the HTTP authorization flow has explicit discovery, PKCE, resource, audience, and token-handling requirements.
CORS WHATWG Fetch Standard, CORS protocol Living Standard Browser cross-origin request and credential behavior.
API deprecation RFC 9745 and RFC 8594 RFCs Deprecation metadata and planned sunset signaling.

Security baselines

Baseline Version Coverage rule
OWASP API Security Top 10 2023 Every API1 through API10 risk has an explicit control section or cross-reference.
OWASP Top 10 for LLM Applications 2025 API-boundary controls are mapped explicitly. Model training and governance topics are marked out of scope where applicable.
OWASP Top 10 for Agentic Applications 2026 Tool, identity, privilege, supply-chain, memory, and inter-agent controls are mapped explicitly.

OWASP API Security Top 10 coverage

Risk Guide location Coverage
API1 Broken Object Level Authorization Authorization tab Explicit
API2 Broken Authentication Auth Mechanisms and JWT Security tabs Explicit
API3 Broken Object Property Level Authorization Authorization tab Explicit
API4 Unrestricted Resource Consumption Rate Limiting tab Explicit
API5 Broken Function Level Authorization Authorization tab Explicit
API6 Unrestricted Access to Sensitive Business Flows Authorization tab Explicit
API7 Server Side Request Forgery API Boundaries tab Explicit
API8 Security Misconfiguration Gateway Controls and CORS tabs Explicit
API9 Improper Inventory Management Versioning tab Explicit
API10 Unsafe Consumption of APIs API Boundaries tab Explicit

OWASP Top 10 for LLM Applications coverage

This mapping covers controls that can be enforced or tested at an API, retrieval, model, or tool boundary. It does not claim to replace model-development governance.

Risk Guide location Coverage
LLM01 Prompt Injection AI-Specific Threats, Prompt Injection card Explicit
LLM02 Sensitive Information Disclosure AI-Specific Threats, Sensitive Data in Model Context card Explicit
LLM03 Supply Chain AI-Specific Threats, AI Supply Chain, Retrieval, and Memory card Explicit
LLM04 Data and Model Poisoning AI-Specific Threats, AI Supply Chain, Retrieval, and Memory card API-boundary subset
LLM05 Improper Output Handling AI-Specific Threats, Prompt Injection and Agent Authority cards; API Boundaries, Request and Response Contracts card Explicit
LLM06 Excessive Agency AI-Specific Threats, Agent Authority and Tool Use card Explicit
LLM07 System Prompt Leakage AI-Specific Threats, Prompt Injection card Explicit
LLM08 Vector and Embedding Weaknesses AI-Specific Threats, AI Supply Chain, Retrieval, and Memory card Explicit
LLM09 Misinformation AI-Specific Threats, Agent Authority and Tool Use card High-impact action subset
LLM10 Unbounded Consumption Rate Limiting tab and Model Endpoint Abuse card Explicit

OWASP Top 10 for Agentic Applications coverage

Risk Guide location Coverage
ASI01 Agent Goal Hijack AI-Specific Threats, Prompt Injection and Agent Authority cards Explicit
ASI02 Tool Misuse and Exploitation AI-Specific Threats, Agent Authority and Tool Use card Explicit
ASI03 Identity and Privilege Abuse JWT Security, Delegation and Identity Chains card; AI-Specific Threats, Agent Authority card Explicit
ASI04 Agentic Supply Chain Vulnerabilities AI-Specific Threats, AI Supply Chain, Retrieval, and Memory card Explicit
ASI05 Unexpected Code Execution API Boundaries, Request and Response Contracts card; AI-Specific Threats, Agent Authority card Explicit
ASI06 Memory and Context Poisoning AI-Specific Threats, AI Supply Chain, Retrieval, and Memory card Explicit
ASI07 Insecure Inter-Agent Communication JWT Security, Delegation and Identity Chains card; Auth Protocols, MCP HTTP Authorization card Explicit
ASI08 Cascading Failures Authorization, Sensitive Business Flows card; AI-Specific Threats, Agent Authority card Explicit
ASI09 Human-Agent Trust Exploitation AI-Specific Threats, Agent Authority and Tool Use card High-impact action subset
ASI10 Rogue Agents AI-Specific Threats, Agent Authority and Tool Use card Explicit

Maintenance rules

  1. Keep dates and version identifiers on claims that can change.
  2. Link requirements to primary standards, not vendor summaries.
  3. Label opinionated defaults as project recommendations.
  4. Do not use regulatory language such as “required for PHI” without a direct legal or regulatory source and jurisdiction.
  5. Revalidate every vendor-comparison cell when its review date changes.
  6. Remove or generate numeric coverage claims. Do not maintain unexplained hand-counted totals.
  7. For every security control, include a negative test or detection signal that can falsify the claim.