AuthHub MCP Gateway
Zero-Trust Policy Enforcement, Upstream Credential Isolation & Per-Call Authorization
The AuthHub MCP Gateway sits between autonomous AI agents and sensitive backend tools. It implements RFC 9728 Protected Resource Metadata, enforces RFC 8707 audience binding to prevent confused-deputy attacks, and evaluates every tool call against a live Google Zanzibar (SpiceDB) relationship graph in under 5 milliseconds — without ever leaking client credentials to upstream servers.
Enterprise Gateway Architecture
Per-Call AuthZEN SARC Gate
Intercepts tools/call, resources/read, and prompts/get. Evaluates Subject, Action, Resource, and Context in <5ms. Same tool + same subject + different resource = distinct PERMIT vs DENY decision.
Zero Token Passthrough (M8)
Complies strictly with Rule M8. Client tokens authorize the client→gateway leg only. Upstream MCP servers receive short-lived, encrypted credentials injected by the gateway, preventing upstream tool compromise.
RFC 8707 Confused-Deputy Guard
Validates that the token's aud or resource indicator matches https://api.authhub.cloud/mcp. Tokens minted for other microservices are immediately rejected with 401.
Real-Time CAEP Revocation
Consumes Continuous Access Evaluation Profile (CAEP) and Shared Signals (SSF) events. Pushes instantaneous notifications/tools/list_changed over SSE to revoke tool access without terminating active sessions.
Database Agent SQL Gating
Dedicated proxy for database agents (PostgreSQL, Snowflake, BigQuery). Parses SQL ASTs, prevents DROP/TRUNCATE queries, enforces row-level filters, and injects tenant tenancy boundaries.
RFC 9728 Discovery Handshake
Returns full protected resource metadata at /.well-known/oauth-protected-resource. Standard 401 challenge includes the metadata pointer, enabling automated discovery in any compliant MCP client.
The 5-Step Gateway Authorization Lifecycle
Click each step to inspect the exact wire protocol headers, payloads, and policy evaluations.
Step 1: Client Probes the MCP Gateway
The client (e.g. MCP Inspector, Claude Desktop) connects without authorization credentials.
POST /mcp HTTP/1.1
Host: api.authhub.cloud
Content-Type: application/json
Accept: application/json, text/event-stream
{
"jsonrpc": "2.0",
"id": 1,
"method": "initialize",
"params": {
"protocolVersion": "2025-11-25",
"capabilities": { "roots": { "listChanged": true } },
"clientInfo": { "name": "mcp-inspector", "version": "0.14.1" }
}
}Verified Interoperability Matrix
Empirical testing records from the OpenID MCP security interoperability programme.
Verified with official Anthropic inspection harness across all gated operations (tools/call, resources/read, prompts/get).
Validated RFC 9728 resource discovery and automated client metadata document registration without static pre-shared keys.
Verified cross-language MCP client connectivity, OAuth 2.1 token issuance, and SSE session management.
Demonstrated automated enterprise governance lifecycle: role changes trigger immediate tool revocation over SSF/CAEP.
Protect your autonomous AI tools today
Deploy AuthHub MCP Gateway in front of internal tools or cloud databases in minutes.