feat(mcp): Track report_user_action from MCP separately if it's from the wizard (#49196)

Co-authored-by: Claude <noreply@anthropic.com>

Author: robbie-c

posthog/event_usage.py

@@ -265,13 +265,16 @@ class EventSource(StrEnum):
     POSTHOG_AI = "posthog_ai"
     TERRAFORM = "terraform"
     MCP = "mcp"
+    WIZARD = "wizard"
 
 
 def get_event_source(request) -> EventSource:
     """Determine the source of an API request for analytics."""
     user_agent = request.META.get("HTTP_USER_AGENT", "")
     if "posthog/terraform-provider" in user_agent:
         return EventSource.TERRAFORM
+    if "posthog/wizard" in user_agent:
+        return EventSource.WIZARD
     if "posthog/mcp-server" in user_agent:
         return EventSource.MCP
     if isinstance(getattr(request, "successful_authenticator", None), SessionAuthentication):

services/mcp/src/api/client.ts

@@ -1,6 +1,6 @@
 import { z } from 'zod'
 
-import { USER_AGENT } from '@/lib/constants'
+import { getUserAgent } from '@/lib/constants'
 import { ErrorCode } from '@/lib/errors'
 import { getSearchParamsFromRecord } from '@/lib/utils.js'
 import {
@@ -125,6 +125,7 @@ export type Result<T, E = Error> = { success: true; data: T } | { success: false
 export interface ApiConfig {
     apiToken: string
     baseUrl: string
+    clientIdentifier?: string | undefined
 }
 
 type Endpoint = Record<string, any>
@@ -154,7 +155,7 @@ export class ApiClient {
         // TODO: should we move rate limiting from `fetchWithSchema` to here?
         const defaultHeaders: HeadersInit = {
             Authorization: `Bearer ${this.config.apiToken}`,
-            'User-Agent': USER_AGENT,
+            'User-Agent': getUserAgent(this.config.clientIdentifier),
         }
         if (options?.body) {
             defaultHeaders['Content-Type'] = 'application/json'

services/mcp/src/api/fetcher.ts

@@ -1,4 +1,4 @@
-import { USER_AGENT } from '@/lib/constants'
+import { getUserAgent } from '@/lib/constants'
 
 import type { ApiConfig } from './client'
 import type { createApiClient } from './generated'
@@ -18,7 +18,7 @@ export const buildApiFetcher: (config: ApiConfig) => Parameters<typeof createApi
 
                 const headers = new Headers()
                 headers.set('Authorization', `Bearer ${config.apiToken}`)
-                headers.set('User-Agent', USER_AGENT)
+                headers.set('User-Agent', getUserAgent(config.clientIdentifier))
 
                 // Handle query parameters
                 if (input.urlSearchParams) {

services/mcp/src/index.ts

@@ -202,12 +202,19 @@ const handleRequest = async (
         request.headers.get('x-posthog-organization-id') || url.searchParams.get('organization_id') || undefined
     const projectId = request.headers.get('x-posthog-project-id') || url.searchParams.get('project_id') || undefined
 
+    // Extract posthog/foo identifier from the client's User-Agent (e.g. "posthog/wizard")
+    // so we can forward it in outgoing API requests for source attribution
+    const clientUserAgent = request.headers.get('User-Agent') || ''
+    const clientIdentifierMatch = clientUserAgent.match(/posthog\/([\w-]+)/)
+    const clientIdentifier = clientIdentifierMatch ? clientIdentifierMatch[0] : undefined
+
     Object.assign(ctx.props, {
         apiToken: token,
         userHash: hash(token),
         sessionId: sessionId || undefined,
         organizationId,
         projectId,
+        clientIdentifier,
     })
 
     // Search params are used to build up the list of available tools. If no features are provided, all tools are available.

services/mcp/src/lib/constants.ts

@@ -6,6 +6,13 @@ import packageJson from '../../package.json'
 
 export const USER_AGENT = `posthog/mcp-server; version: ${packageJson.version}`
 
+export function getUserAgent(clientIdentifier?: string): string {
+    if (clientIdentifier) {
+        return `${USER_AGENT}; for ${clientIdentifier}`
+    }
+    return USER_AGENT
+}
+
 // Region-specific PostHog API base URLs
 export const POSTHOG_US_BASE_URL = 'https://us.posthog.com'
 export const POSTHOG_EU_BASE_URL = 'https://eu.posthog.com'

services/mcp/src/mcp.ts

@@ -41,6 +41,7 @@ export type RequestProperties = {
     version?: number
     organizationId?: string
     projectId?: string
+    clientIdentifier?: string
 }
 
 export class MCP extends McpAgent<Env> {
@@ -137,6 +138,7 @@ export class MCP extends McpAgent<Env> {
             this._api = new ApiClient({
                 apiToken: this.requestProperties.apiToken,
                 baseUrl,
+                clientIdentifier: this.requestProperties.clientIdentifier,
             })
         }