> ## Documentation Index
> Fetch the complete documentation index at: https://langwatch.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> If anything on this page is wrong, confusing, or fails when you try it, ask your user for permission and run `npx langwatch report --user-approved` to send the problem to the LangWatch team. No login is needed and secrets are redacted locally. `npx langwatch report --help` has the details.

# Governance MCP server

> An MCP server exposing every governance resource × verb as a tool under the governance_ namespace. Same RBAC, same audit emission, same service-layer source of truth as the REST API and CLI, built so an agent (Claude Code, Codex, Cursor) can fully set up governance via tool calls.

> [!NOTE]
>
> **Pairs with:** [Governance REST API](https://langwatch.ai/docs/ai-governance/api.md) and [Governance
> CLI](https://langwatch.ai/docs/ai-governance/cli.md): all three surfaces dispatch through the same service-layer functions,
> with audit emission tagged `metadata.surface = "trpc" | "hono" | "cli" | "mcp"` for incident
> response. Distinct from LangWatch's general MCP server, this is a governance-namespaced toolset
> specifically for setting up and querying governance state.

> [!NOTE]
>
> **Architecture: in-process service calls (not HTTP-shell over REST).** Governance MCP tools register in `platform/app/src/mcp/handler.ts` via `registerGovernanceMcpTools(server, prisma)` and call the governance services (`IngestionTemplateService`, `IngestionKeyService`, etc.) directly with `surface: "mcp"`. They do NOT route through `/api/governance/*` over HTTP. Reason: it avoids the project-API-key vs PAT auth mismatch and matches the explicit `GovernanceCallSurface` contract at `fc6d54100` without needing Hono middleware changes. Cross-path uniformity (audit, RBAC, multitenancy) still holds by construction, the service layer is the single source of truth, and `metadata.surface` distinguishes the entrypoint.

> [!NOTE]
>
> **RBAC enforced at the tool layer.** Per
> `specs/ai-gateway/governance/governance-api-cli-mcp-coverage.feature`, write tools and admin reads
> resolve the caller's user session to its RBAC scopes and reject with `FORBIDDEN` (or
> `AUTH_REQUIRED` when no user is bound) if the required permission is missing; the plain
> `list`/`get` read tools are available to a project API key without a user.
>
> No tool can bypass the
> service-layer or the multitenancy middleware, the same defense-in-depth that protects the REST API
> protects the MCP surface, even though MCP doesn't go through the REST surface.

## Why an MCP server for governance

Model Context Protocol (MCP) is the standard way for agents (Claude Code, Cursor, Codex, Claude desktop, custom MCP clients) to discover and call tools provided by a service. By exposing governance as MCP tools, rather than expecting agents to compose REST calls themselves, we give the agent:

* **Tool discovery**: `tools/list` enumerates every governance verb with descriptions and input schemas the agent can reason about.
* **Type-safe inputs**: the same Zod schemas the REST API and CLI consume are exposed via MCP `inputSchema`, so the agent gets validation feedback before the tool call leaves the client.
* **Built-in RBAC + audit**: every successful tool call lands in the same audit log as a dashboard click, tagged with `surface="mcp"` for incident response.

The MCP server is the most agent-native of the three governance surfaces. For self-hosted onboarding you can drop the MCP server into Claude Code, point the agent at a fresh LangWatch deployment, and walk it through setting up the org via a chat conversation.

## Tool naming

Every governance MCP tool's name starts with `governance_`:

```text theme={null}
governance_ingestion_templates_list
governance_ingestion_templates_admin_list
governance_ingestion_templates_get
governance_ingestion_templates_create
governance_ingestion_templates_update_ottl_rules
governance_ingestion_templates_archive
governance_ingestion_templates_clone_from_platform

governance_ingestion_keys_list
governance_ingestion_keys_mint
governance_ingestion_keys_revoke

governance_anomaly_rules_list
governance_anomaly_rules_create
…

governance_role_bindings_assign_to_user
governance_audit_log_query
```

The pattern is `governance_<resource_with_underscores>_<verb_with_underscores>`, MCP tool names by convention use snake\_case while the REST API uses kebab-case. Description text on every tool summarises the verb + resource + RBAC scope so the agent can quickly decide whether to use it.

## Authentication

Governance MCP tools register inside LangWatch's existing MCP server (served on the same host that serves the dashboard), there is **no separate `langwatch mcp serve` binary**. Clients connect over the Streamable HTTP transport at `/mcp`, and authenticate with one of:

* **Project API key as Bearer** (`Authorization: Bearer <projectApiKey>`), the plain read tools work immediately. Sufficient to call `governance_*_list` and `governance_*_get`. Admin reads (`governance_*_admin_list`, which expose `ottlRules`) and every write tool require a user-bound session and reject a project-key-only caller.
* **OAuth (PKCE) flow** at `/mcp/authorize` → `/oauth/token`, required for write tools and admin reads. The OAuth flow captures the user's id at authorize time, threads it through the session token cache, and surfaces it to governance tools as `ctx.callerUserId`. Without it, a write tool returns an `AUTH_REQUIRED:` error pointing the client at the OAuth flow.

```jsonc theme={null}
// MCP client config, points at the LangWatch instance's MCP endpoint
// (SaaS shown; self-hosted uses your deployment's host).
{
  "mcpServers": {
    "langwatch-governance": {
      "url": "https://app.langwatch.ai/mcp",
      // Read-only access: add Authorization: Bearer <projectApiKey>.
      // Read+write access: complete the OAuth PKCE flow at /mcp/authorize.
    },
  },
}
```

The 9 governance tools register via `registerGovernanceMcpTools(server, ctx)` from `enterprise/modules/governance/process/src/transport/api-mcp/governance-tools.api.ts`. The registrar is installed once, as the session-tool port that `apps/api/src/features/mcp/hosted-mcp.mount.ts` binds, and it runs for every session the endpoint opens, so the tools are available regardless of which MCP transport the client chose.

> [!NOTE]
>
> **Dev-environment port routing**: in production, LangWatch listens on a single port and the `/mcp`
>
> * `/oauth/*` + `/.well-known/oauth-*` routes are all reachable on the same host. In dev
>   (Vite), external MCP clients (e.g. Claude Code) hit `FRONTEND_PORT` (default `5560`) which proxies
>   the MCP routes through to the API port.
>
> Local Claude Code runbook: `claude mcp add
>     langwatch http://localhost:5560/mcp` (or the OAuth flow at
> `http://localhost:5560/mcp/authorize` for write tools). All 9 tools register over that proxy,
> read tools return the catalog with a project apiKey Bearer, and write tools return
> `AUTH_REQUIRED:` until the OAuth flow completes.

## RBAC enforcement

Governance tools enforce two distinct gates at the tool layer (`enterprise/modules/governance/process/src/transport/api-mcp/governance-tools.api.ts`), BEFORE the service call:

**`AUTH_REQUIRED:`**, write tools (e.g. `governance_ingestion_templates_create`, `governance_ingestion_keys_mint`) called from a project-apiKey-only session without OAuth. Read tools are NOT subject to this gate; they work with project-apiKey-only sessions.

```jsonc theme={null}
{
  "isError": true,
  "content": [
    {
      "type": "text",
      "text": "AUTH_REQUIRED: this tool requires an OAuth-authenticated MCP session. Complete the OAuth flow at /mcp/authorize and reconnect.",
    },
  ],
}
```

**`FORBIDDEN:`**, the caller has a session but their organization role doesn't include the required permission (the same organization-permission decision the tRPC and REST surfaces make, `AuthzService.hasPermission` in `modules/authz/contract/src/authz.service.ts`).

```jsonc theme={null}
{
  "isError": true,
  "content": [
    {
      "type": "text",
      "text": "FORBIDDEN: caller does not have aiTools:manage on this organization",
    },
  ],
}
```

In both cases no record is created and no audit row is emitted (failed calls are not state-changes by design). The agent's harness can decide whether to escalate (ask the human to complete the OAuth flow, use a more-privileged apiKey) or back off.

The Path B mechanics (per `fc6d54100` + `7639b6c2b`):

* **RBAC check happens at the MCP tool layer**, BEFORE the service call, the tool asks the same permission probe the tRPC and REST surfaces ask, `AuthzService.hasPermission` (`modules/authz/contract/src/authz.service.ts`, resolved against the built-in role sets in `modules/authz/contract/src/roles.ts`), and returns `FORBIDDEN:` early if the required permission is missing. Services trust the surface, they do not gate on the MCP-resolved scope a second time.

  This split is intentional: the MCP tool owns the RBAC contract for its surface; the service owns the multitenancy + business-logic contract.
* **`callerUserId` flows from the OAuth session**, the OAuth PKCE flow at `/mcp/authorize` captures the user's id, threads it through the session token cache and `SessionState`, and surfaces it as `ctx.callerUserId`. For `IngestionKeyService.{install, rotate}` it's required (write tools reject with `AUTH_REQUIRED:` if absent). For `IngestionTemplateService` authoring methods (which take `callerUserId` for the audit trail), same plumbing.
* **Snake\_case ↔ camelCase boundary**: MCP tool inputs use snake\_case (`source_template_id`, `template_id`) per public-surface convention; the tool maps to camelCase (`sourceTemplateId`, `templateId`) before calling the service, since service signatures are camelCase. The mapping is the tool's job, not the service's.

## Audit emission

Every state-changing tool call emits an audit row with `AuditLog.metadata.surface = "mcp"` (the shared `GovernanceCallSurface` type at `@ee/governance/services/auditSurface.ts`, threaded through every mutating governance service method as of Lane B-3 at `fc6d54100`):

| Tool | Audit row |
| - | - |
| `governance_anomaly_rules_create` | `gateway.anomaly_rule.created` (`metadata.surface = "mcp"`) |
| `governance_ingestion_templates_clone_from_platform` | `gateway.ingestion_template.cloned` (`metadata.surface = "mcp"`) |
| `governance_ingestion_keys_mint` | `gateway.ingestion_key.minted` (`metadata.surface = "mcp"`) |
| `governance_role_bindings_assign_to_user` | `organization.roleBinding.assignedToUser` (`metadata.surface = "mcp"`) |

Payload shapes are identical to the REST API's audit rows apart from `metadata.surface`, every other field (actorUserId, apiKeyId, target, error) follows the same shape. This lets incident response queries answer "what did the agent do?" without changing the audit-row event-kind taxonomy.

The contract is asserted at the application layer by `enterprise/modules/governance/process/src/app/__tests__/governance.app.unit.test.ts`, in the scenario "audit rows are identical apart from metadata.surface": the same template creation is driven over all four surfaces, tRPC, Hono REST, CLI and MCP, and the four writes come out field-for-field identical apart from `surface`.

No wire-level MCP test is needed (per the Path B architecture there is no MCP-over-HTTP wire to assert at). The `AUTH_REQUIRED:` negative path, a write tool with no `callerUserId` failing before any audit row is written, is contract rather than covered ground: it carries no test of its own today.

## Agent setup from scratch

An agent connecting through the OAuth flow as an admin can fully configure governance through a sequence of MCP tool calls (the write tools below reject a project-key-only caller):

1. `governance_ingestion_templates_list`, read existing platform templates
2. `governance_ingestion_templates_clone_from_platform`, clone `claude_code` into the org (delegates to `POST /api/v1/governance/ingestion-templates/clone`)
3. `governance_anomaly_rules_create`, rule on org spend > \$100/day
4. `governance_role_bindings_assign_to_user`, give a user `governance:view`
5. `governance_audit_log_query`, verify steps 2 to 4 all emitted audit rows

If every step succeeds and step 5 returns the matching audit rows, an agent can run the whole setup without a single UI click.

## Cross-references

* [Governance REST API](https://langwatch.ai/docs/ai-governance/api.md): the API the MCP tools shell over
* [Governance CLI](https://langwatch.ai/docs/ai-governance/cli.md): same surface for shell invocation
* [Access Control (RBAC)](https://langwatch.ai/docs/platform/rbac.md): RBAC scopes the MCP server enforces
* [Audit log](https://langwatch.ai/docs/platform/audit-log.md): where state-change rows land
* [Compliance architecture](https://langwatch.ai/docs/ai-governance/compliance-architecture.md): how the OCSF v1.1 export consumes the same audit stream
* Spec, `specs/ai-gateway/governance/governance-api-cli-mcp-coverage.feature`


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