AgentMesh MCP Rust crate

Standalone Rust crate for the Agent Governance Toolkit MCP governance/security surface — response scanning, message signing, session authentication, credential redaction, rate limiting, tool metadata scanning, gateway decisions, and categorical metrics.

Public Preview — APIs may change before 1.0.

Install

[dependencies]

agentmesh-mcp = "3.0.2"

Quick Start

use agentmesh_mcp::{
    CredentialRedactor, InMemoryNonceStore, McpMessageSigner, McpSignedMessage,
    SystemClock, SystemNonceGenerator,
};
use std::sync::Arc;
use std::time::Duration;

let signer = McpMessageSigner::new(
    b"top-secret-signing-key".to_vec(),
    Arc::new(SystemClock),
    Arc::new(SystemNonceGenerator),
    Arc::new(InMemoryNonceStore::default()),
    Duration::from_secs(300),
    Duration::from_secs(600),
)?;

let signed: McpSignedMessage = signer.sign("hello from mcp")?;
signer.verify(&signed)?;

let redactor = CredentialRedactor::new()?;
let result = redactor.redact("Authorization: Bearer super-secret-token");
assert!(result.sanitized.contains("[REDACTED_BEARER_TOKEN]"));
# Ok::<(), agentmesh_mcp::McpError>(())

Authenticated MCP Gateway

McpGateway no longer accepts caller-asserted agent identity on the unauthenticated request path. Configure a session authenticator and call process_authenticated_request.

use agentmesh_mcp::{
    CredentialRedactor, DeterministicNonceGenerator, FixedClock, InMemoryAuditSink,
    InMemoryRateLimitStore, InMemorySessionStore, McpGateway, McpGatewayConfig,
    McpGatewayRequest, McpMetricsCollector, McpResponseScanner,
    McpSessionAuthenticator, McpSlidingRateLimiter, SystemClock,
};
use std::sync::Arc;
use std::time::{Duration, SystemTime};

let redactor = CredentialRedactor::new()?;
let audit = Arc::new(InMemoryAuditSink::new(redactor.clone()));
let metrics = McpMetricsCollector::default();
let scanner = McpResponseScanner::new(
    redactor,
    audit.clone(),
    metrics.clone(),
    Arc::new(SystemClock),
)?;
let limiter = McpSlidingRateLimiter::new(
    10,
    Duration::from_secs(60),
    Arc::new(SystemClock),
    Arc::new(InMemoryRateLimitStore::default()),
)?;
let session_authenticator = McpSessionAuthenticator::new(
    b"0123456789abcdef0123456789abcdef".to_vec(),
    Arc::new(FixedClock::new(SystemTime::UNIX_EPOCH)),
    Arc::new(DeterministicNonceGenerator::from_values(vec!["session-1".into()])),
    Arc::new(InMemorySessionStore::default()),
    Duration::from_secs(300),
    4,
)?;
let issued = session_authenticator.issue_session("did:agentmesh:gateway")?;
let gateway = McpGateway::new(
    McpGatewayConfig::default(),
    scanner,
    limiter,
    audit,
    metrics,
    Arc::new(SystemClock),
)
.with_session_authenticator(session_authenticator);

let decision = gateway.process_authenticated_request(
    &McpGatewayRequest {
        agent_id: "did:agentmesh:gateway".into(),
        tool_name: "db.read".into(),
        payload: serde_json::json!({"query": "select 1"}),
    },
    &issued.token,
)?;
assert!(decision.allowed);
# Ok::<(), agentmesh_mcp::McpError>(())

Migration note

If you were using McpGateway::process_request, migrate to process_authenticated_request and supply a session token from McpSessionAuthenticator. Requests without verified session identity now fail closed.

Also Available in the Full SDK

If you also need trust, identity, policy, and audit primitives, install the full crate instead:

cargo add agentmesh

License

See repository root LICENSE.