Your first governed tool call

This is the end‑to‑end loop that makes MCP Gateway “governed”: you only ever see the tools policy allows, calls are enforced and brokered at the data plane, and everything lands in the audit trail.

1. Discover what you can use. The catalog is policy‑filtered — tools you aren’t allowed to call don’t appear at all.

2. Call an allowed tool. The data plane authenticates you, evaluates policy, brokers the credential, and routes to the approved backend.

3. See it in the audit trail. Both the allowed call and any denied attempt are recorded as metadata‑only events.

1 · Discover allowed tools (catalog‑lite)

List the tools you're allowed to call

UIAPICLI

1. Open Govern → Catalog in the console.
2. The catalog shows only the servers and tools your policy permits — unauthorized tools are hidden, not greyed out.

GET/v1/catalog/capabilities

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curl "$GATEWAY/v1/catalog/capabilities?environment_id=prod" \
-H "authorization: Bearer $TOKEN"

View queryCatalogLite in the API reference →

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gatewayctl call-tool --help

Discovery is exposed via the API (GET /v1/catalog/capabilities). Use gatewayctl call-tool to invoke a tool once you know its name.

2 · Call an allowed tool

The actual tool invocation happens at the data plane (:8081), which enforces policy and brokers credentials on every request.

Invoke a governed tool

UIAPICLI

1. From the catalog, open a tool you're allowed to call.
2. Fill in the tool's input fields and run it — the response comes back through the gateway.

POST/v1/mcp/servers/{server_id}

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curl -X POST "$DATA_PLANE/v1/mcp/servers/legal-contract-review" \
-H "authorization: Bearer $TOKEN" \
-H "content-type: application/json" \
--data '{"jsonrpc":"2.0","id":"1","method":"tools/call",
         "params":{"name":"contract_read","arguments":{}}}'

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gatewayctl call-tool --server legal-contract-review --tool contract_read

Every gatewayctl verb accepts --format text|json.

Try a denied call

Call a tool you don’t have access to. The gateway returns a stable machine reason and hidden‑tool evidence, exits non‑zero, and never leaks the request payload or any secret material — exactly what you want governance to do.

3 · See it in the audit trail

Every decision — allow or deny — is recorded. Head to Search the audit trail to find the two events you just generated.

See it illustrated Watch the whole request lifecycle — allowed vs denied — illustrated step by step.