feat: report MCP client telemetry (#242)

docs-site/content/docs/community/telemetry.mdx

@@ -3,10 +3,14 @@ title: Telemetry
 description: Understand what anonymous usage telemetry ktx collects and how to opt out.
 ---
 
-**ktx** collects anonymous, aggregated usage telemetry from interactive CLI
+**ktx** collects anonymous, aggregated usage telemetry so maintainers can see
-runs so maintainers can see which commands work, where setup fails, and which
+which commands work, where setup fails, and which parts of the data-agent
-parts of the data-agent workflow need improvement. Telemetry is opt-out and
+workflow need improvement. Telemetry is opt-out: it turns on the first time you
-disabled automatically in CI and non-interactive runs.
+run **ktx** in an interactive terminal, which prints a one-time notice. From
+then on the same install also reports background activity that has no terminal
+of its own, such as the local MCP server your agent calls. It stays disabled in
+CI, whenever an opt-out is set, and until that first interactive run has shown
+the notice.
 
 ## Opt out
 
@@ -17,8 +21,7 @@ Use any of these mechanisms to disable telemetry:
 | `export KTX_TELEMETRY_DISABLED=1` | Disables telemetry for the shell and child processes |
 | `export DO_NOT_TRACK=1` | Standard do-not-track environment variable |
 | `CI=1` | Automatic in CI |
-| Non-TTY output | Automatic for pipes and scripts |
+| Edit `~/.ktx/telemetry.json` and set `"enabled": false` | Persistent for the machine, including the MCP server |
-| Edit `~/.ktx/telemetry.json` and set `"enabled": false` | Persistent for the machine |
 
 ## What we collect
 
@@ -27,6 +30,11 @@ succeed or fail, and basic environment metadata (CLI version, Node version, OS
 platform). For project-level analysis, **ktx** sends a salted hash of the
 project directory — never the raw path.
 
+When an agent reaches **ktx** through MCP, we also record the connecting client
+tool's self-reported name and version (for example Claude Desktop, Cursor, or
+Cline) so we can see which agents people use **ktx** with. That describes the
+tool, never you or your data.
+
 ## What we never collect
 
 - File paths, hostnames, environment variable values, or command arguments

packages/cli/src/context/mcp/context-tools.ts

@@ -6,6 +6,7 @@ import type { MemoryAgentInput } from '../../context/memory/types.js';
 import { emitTelemetryEvent, mcpTelemetrySampleRate, shouldEmitMcpTelemetry } from '../../telemetry/index.js';
 import { scrubErrorClass } from '../../telemetry/scrubber.js';
 import type {
+  KtxMcpClientInfo,
   KtxMcpContextPorts,
   KtxMcpProgressCallback,
   KtxMcpServerLike,
@@ -22,6 +23,7 @@ export interface RegisterKtxContextToolsDeps {
   userContext: KtxMcpUserContext;
   projectDir?: string;
   io?: KtxCliIo;
+  getClientInfo?: () => KtxMcpClientInfo | undefined;
 }
 
 const connectionIdSchema = z.string().min(1);
@@ -526,9 +528,24 @@ function registerParsedTool<TSchema extends z.ZodType>(
   });
 }
 
+/**
+ * Resolves the connected client's identity into the raw telemetry fields. The
+ * strings are client-controlled and untrusted, so they only ever land in the
+ * telemetry property bag — never in paths, logs, or error messages.
+ */
+function clientTelemetryFields(
+  getClientInfo: (() => KtxMcpClientInfo | undefined) | undefined,
+): { mcpClientName?: string; mcpClientVersion?: string } {
+  const client = getClientInfo?.();
+  return {
+    ...(client?.name ? { mcpClientName: client.name } : {}),
+    ...(client?.version ? { mcpClientVersion: client.version } : {}),
+  };
+}
+
 function instrumentMcpServer(
   server: KtxMcpServerLike,
-  telemetry: { projectDir?: string; io?: KtxCliIo },
+  telemetry: { projectDir?: string; io?: KtxCliIo; getClientInfo?: () => KtxMcpClientInfo | undefined },
 ): KtxMcpServerLike {
   return {
     registerTool(name, config, handler) {
@@ -548,6 +565,7 @@ function instrumentMcpServer(
                 outcome: isError ? 'error' : 'ok',
                 durationMs: Math.max(0, performance.now() - startedAt),
                 sampleRate: mcpTelemetrySampleRate(),
+                ...clientTelemetryFields(telemetry.getClientInfo),
               },
             });
           }
@@ -565,6 +583,7 @@ function instrumentMcpServer(
                 ...(errorClass ? { errorClass } : {}),
                 durationMs: Math.max(0, performance.now() - startedAt),
                 sampleRate: mcpTelemetrySampleRate(),
+                ...clientTelemetryFields(telemetry.getClientInfo),
               },
             });
           }
@@ -577,7 +596,11 @@ function instrumentMcpServer(
 
 export function registerKtxContextTools(deps: RegisterKtxContextToolsDeps): void {
   const { ports, userContext } = deps;
-  const server = instrumentMcpServer(deps.server, { projectDir: deps.projectDir, io: deps.io });
+  const server = instrumentMcpServer(deps.server, {
+    projectDir: deps.projectDir,
+    io: deps.io,
+    getClientInfo: deps.getClientInfo,
+  });
 
   if (ports.connections) {
     const connections = ports.connections;

packages/cli/src/context/mcp/server.ts

@@ -11,6 +11,7 @@ export function createKtxMcpServer(deps: KtxMcpServerDeps): KtxMcpServerDeps['se
       userContext: deps.userContext,
       projectDir: deps.projectDir,
       io: deps.io,
+      getClientInfo: deps.getClientInfo,
     });
   }
 
@@ -30,6 +31,9 @@ export function createDefaultKtxMcpServer(
     contextTools: deps.contextTools,
     projectDir: deps.projectDir,
     io: deps.io,
+    // The SDK populates the client identity after the initialize handshake, so
+    // read it lazily at emit time rather than at registration (undefined here).
+    getClientInfo: () => server.server.getClientVersion(),
   });
   return server;
 }

packages/cli/src/context/mcp/types.ts

@@ -50,6 +50,16 @@ export interface KtxMcpUserContext {
   userId: string;
 }
 
+/**
+ * Identity of the connected MCP client tool (e.g. Claude Desktop, Cursor),
+ * read from the initialize handshake. Untrusted, client-controlled strings —
+ * use only as telemetry properties, never to build paths or log lines.
+ */
+export interface KtxMcpClientInfo {
+  name: string;
+  version: string;
+}
+
 export interface KtxMcpServerLike {
   registerTool(
     name: string,
@@ -177,4 +187,6 @@ export interface KtxMcpServerDeps {
   contextTools?: KtxMcpContextPorts;
   projectDir?: string;
   io?: KtxCliIo;
+  /** Reads the connected client's identity once the initialize handshake completes. */
+  getClientInfo?: () => KtxMcpClientInfo | undefined;
 }

packages/cli/src/telemetry/events.schema.json

@@ -157,7 +157,9 @@
         "outcome",
         "durationMs",
         "errorClass",
-        "sampleRate"
+        "sampleRate",
+        "mcpClientName",
+        "mcpClientVersion"
       ]
     },
     {
@@ -1131,7 +1133,13 @@
         },
         "sampleRate": {
           "type": "number",
-          "const": 0.1
+          "const": 1
+        },
+        "mcpClientName": {
+          "type": "string"
+        },
+        "mcpClientVersion": {
+          "type": "string"
         }
       },
       "required": [

packages/cli/src/telemetry/events.ts

@@ -156,7 +156,12 @@ const mcpRequestCompletedSchema = telemetryCommonEnvelopeSchema
     outcome: outcomeSchema,
     durationMs: z.number().nonnegative(),
     errorClass: z.string().optional(),
-    sampleRate: z.literal(0.1),
+    sampleRate: z.literal(1),
+    // Raw, client-tool-controlled identity from the MCP initialize handshake
+    // (clientInfo.name/version). Optional: clients may omit clientInfo. Stored
+    // verbatim — normalize the free-form names at query time, not at write time.
+    mcpClientName: z.string().optional(),
+    mcpClientVersion: z.string().optional(),
   })
   .strict();
 
@@ -325,7 +330,7 @@ export const telemetryEventCatalog = [
   {
     name: 'mcp_request_completed',
     description: 'Emitted for sampled MCP tool requests.',
-    fields: ['toolName', 'outcome', 'durationMs', 'errorClass', 'sampleRate'],
+    fields: ['toolName', 'outcome', 'durationMs', 'errorClass', 'sampleRate', 'mcpClientName', 'mcpClientVersion'],
   },
   {
     name: 'daemon_started',

packages/cli/src/telemetry/identity.ts

@@ -75,17 +75,14 @@ export async function loadTelemetryIdentity(options: LoadTelemetryIdentityOption
   const env = options.env ?? process.env;
   const path = telemetryPath(options.homeDir ?? homedir());
 
-  if (envDisablesTelemetry(env) || options.stdoutIsTTY !== true) {
+  if (envDisablesTelemetry(env)) {
-    const existing = await readTelemetryFile(path);
+    return { enabled: false, createdFile: false, noticeShown: false, path };
-    return {
-      installId: existing?.installId,
-      enabled: false,
-      createdFile: false,
-      noticeShown: false,
-      path,
-    };
   }
 
+  // Honor an already-consented identity regardless of the current surface.
+  // Telemetry enablement follows the persisted decision and opt-out env vars,
+  // not whether this invocation happens to own a TTY — MCP servers always run
+  // headless (stdio stubs stdout; the HTTP server runs detached).
   const existing = await readTelemetryFile(path);
   if (existing) {
     return {
@@ -97,6 +94,13 @@ export async function loadTelemetryIdentity(options: LoadTelemetryIdentityOption
     };
   }
 
+  // No identity yet. Minting one means showing the one-time opt-out notice, so
+  // first-run creation requires an interactive surface; a headless first run
+  // stays disabled and defers enablement until the next interactive run.
+  if (options.stdoutIsTTY !== true) {
+    return { enabled: false, createdFile: false, noticeShown: false, path };
+  }
+
   const timestamp = (options.now ?? (() => new Date()))().toISOString();
   const next = {
     installId: randomUUID(),

packages/cli/src/telemetry/index.ts

@@ -52,7 +52,11 @@ type TelemetryEventFields<Name extends TelemetryEventName> = Omit<
 >;
 
 const emittedProjectSnapshots = new Set<string>();
-const MCP_SAMPLE_RATE = 0.1 as const;
+// MCP tool calls are captured at full rate while ktx is early-stage: at current
+// install counts any sampling below 1.0 yields too few events to be useful, and
+// the recorded sampleRate lets us dial this down (and reweight history) once
+// per-session call volume justifies it.
+const MCP_SAMPLE_RATE = 1 as const;
 let mcpSampled: boolean | undefined;
 
 function telemetryDebugEnabled(): boolean {
@@ -64,7 +68,7 @@ export function shouldEmitMcpTelemetry(): boolean {
   return mcpSampled;
 }
 
-export function mcpTelemetrySampleRate(): 0.1 {
+export function mcpTelemetrySampleRate(): 1 {
   return MCP_SAMPLE_RATE;
 }
 

packages/cli/test/context/mcp/server.test.ts

@@ -47,10 +47,10 @@ function makeFakeServer() {
   };
 }
 
-function makeIo() {
+function makeIo(stdoutIsTTY = true) {
   let stderr = '';
   return {
-    stdout: { isTTY: true, write() {} },
+    stdout: { isTTY: stdoutIsTTY, write() {} },
     stderr: {
       write(chunk: string) {
         stderr += chunk;
@@ -272,8 +272,48 @@ describe('createKtxMcpServer', () => {
 
     expect(io.stderrText()).toContain('"event":"mcp_request_completed"');
     expect(io.stderrText()).toContain('"toolName":"wiki_search"');
-    expect(io.stderrText()).toContain('"sampleRate":0.1');
+    expect(io.stderrText()).toContain('"sampleRate":1');
     expect(io.stderrText()).not.toContain(projectDir);
+    // No client connected through the SDK here, so getClientInfo is absent: the
+    // event still emits and the optional client fields are simply omitted.
+    expect(io.stderrText()).not.toContain('mcpClientName');
+    expect(io.stderrText()).not.toContain('mcpClientVersion');
+  });
+
+  it('captures the connecting MCP client name and version', async () => {
+    vi.stubEnv('KTX_TELEMETRY_DEBUG', '1');
+    vi.stubEnv('CI', '');
+    // Non-TTY io keeps the test hermetic (no ~/.ktx/telemetry.json is created)
+    // and mirrors a real headless MCP server; debug mode still emits the payload.
+    const io = makeIo(false);
+
+    const server = createDefaultKtxMcpServer({
+      name: 'ktx-test',
+      version: '0.0.0-test',
+      userContext: { userId: 'mcp-user' },
+      projectDir: '/tmp/ktx-mcp-client-telemetry',
+      io,
+      contextTools: {
+        knowledge: {
+          search: vi.fn<KtxKnowledgeMcpPort['search']>().mockResolvedValue({ results: [], totalFound: 0 }),
+          read: vi.fn<KtxKnowledgeMcpPort['read']>().mockResolvedValue(null),
+        },
+      },
+    });
+    const client = new Client({ name: 'test-agent', version: '9.9.9' });
+    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
+    await Promise.all([server.connect(serverTransport), client.connect(clientTransport)]);
+
+    try {
+      await client.callTool({ name: 'wiki_search', arguments: { query: 'revenue recognition', limit: 5 } });
+    } finally {
+      await client.close();
+      await server.close();
+    }
+
+    expect(io.stderrText()).toContain('"event":"mcp_request_completed"');
+    expect(io.stderrText()).toContain('"mcpClientName":"test-agent"');
+    expect(io.stderrText()).toContain('"mcpClientVersion":"9.9.9"');
   });
 
   it('registers parser-gated sql_execution when the host provides a SQL execution port', async () => {

packages/cli/test/telemetry/events.snapshot.test.ts

@@ -128,7 +128,9 @@ describe('telemetry privacy snapshot', () => {
         outcome: 'error',
         errorClass: 'KtxProjectMissingAbortError',
         durationMs: 12,
-        sampleRate: 0.1,
+        sampleRate: 1,
+        mcpClientName: 'Claude Desktop',
+        mcpClientVersion: '0.7.1',
       }),
     ];
 

packages/cli/test/telemetry/identity.test.ts

@@ -146,6 +146,75 @@ describe('telemetry identity', () => {
     });
   });
 
+  it('enables a consented identity without a TTY (MCP servers run headless)', async () => {
+    await mkdir(join(homeDir, '.ktx'), { recursive: true });
+    await writeFile(
+      join(homeDir, '.ktx', 'telemetry.json'),
+      JSON.stringify(
+        {
+          installId: '00000000-0000-4000-8000-000000000000',
+          enabled: true,
+          noticeShownAt: '2026-05-22T14:33:02.000Z',
+          noticeShownVersion: 1,
+          createdAt: '2026-05-22T14:33:02.000Z',
+        },
+        null,
+        2,
+      ) + '\n',
+      'utf-8',
+    );
+    const testIo = makeIo(false);
+
+    await expect(
+      loadTelemetryIdentity({
+        homeDir,
+        env,
+        stdoutIsTTY: false,
+        stderr: testIo.io.stderr,
+        now: () => new Date('2026-05-22T15:00:00.000Z'),
+      }),
+    ).resolves.toMatchObject({
+      installId: '00000000-0000-4000-8000-000000000000',
+      enabled: true,
+      createdFile: false,
+      noticeShown: false,
+    });
+    // The one-time notice belongs to interactive surfaces only; a headless load
+    // must never write it (the MCP stdio protocol shares the process streams).
+    expect(testIo.stderr()).toBe('');
+  });
+
+  it('keeps opt-outs suppressing a consented identity without a TTY', async () => {
+    await mkdir(join(homeDir, '.ktx'), { recursive: true });
+    await writeFile(
+      join(homeDir, '.ktx', 'telemetry.json'),
+      JSON.stringify(
+        {
+          installId: '00000000-0000-4000-8000-000000000000',
+          enabled: true,
+          noticeShownAt: '2026-05-22T14:33:02.000Z',
+          noticeShownVersion: 1,
+          createdAt: '2026-05-22T14:33:02.000Z',
+        },
+        null,
+        2,
+      ) + '\n',
+      'utf-8',
+    );
+
+    for (const optOut of [{ KTX_TELEMETRY_DISABLED: '1' }, { DO_NOT_TRACK: '1' }, { CI: '1' }]) {
+      await expect(
+        loadTelemetryIdentity({
+          homeDir,
+          env: optOut,
+          stdoutIsTTY: false,
+          stderr: makeIo(false).io.stderr,
+          now: () => new Date('2026-05-22T15:00:00.000Z'),
+        }),
+      ).resolves.toMatchObject({ enabled: false });
+    }
+  });
+
   it('recreates a corrupted file instead of surfacing an error to users', async () => {
     await mkdir(join(homeDir, '.ktx'), { recursive: true });
     await writeFile(join(homeDir, '.ktx', 'telemetry.json'), '{bad json', 'utf-8');

python/ktx-daemon/src/ktx_daemon/telemetry/events.schema.json

@@ -157,7 +157,9 @@
         "outcome",
         "durationMs",
         "errorClass",
-        "sampleRate"
+        "sampleRate",
+        "mcpClientName",
+        "mcpClientVersion"
       ]
     },
     {
@@ -1131,7 +1133,13 @@
         },
         "sampleRate": {
           "type": "number",
-          "const": 0.1
+          "const": 1
+        },
+        "mcpClientName": {
+          "type": "string"
+        },
+        "mcpClientVersion": {
+          "type": "string"
         }
       },
       "required": [