Add support for HTTP OpenTelemetry exporters (#6357)

10 files changed, 301 insertions, 34 deletions

diff --git a/docs/cli/configuration.md b/docs/cli/configuration.md
index d95793f1..963c7f32 100644
--- a/docs/cli/configuration.md
+++ b/docs/cli/configuration.md
@@ -435,6 +435,8 @@ Arguments passed directly when running the CLI can override other configurations
   - Sets the telemetry target. See [telemetry](../telemetry.md) for more information.
 - **`--telemetry-otlp-endpoint`**:
   - Sets the OTLP endpoint for telemetry. See [telemetry](../telemetry.md) for more information.
+- **`--telemetry-otlp-protocol`**:
+  - Sets the OTLP protocol for telemetry (`grpc` or `http`). Defaults to `grpc`. See [telemetry](../telemetry.md) for more information.
 - **`--telemetry-log-prompts`**:
   - Enables logging of prompts for telemetry. See [telemetry](../telemetry.md) for more information.
 - **`--checkpointing`**:
diff --git a/docs/telemetry.md b/docs/telemetry.md
index 68c3aed2..6767e349 100644
--- a/docs/telemetry.md
+++ b/docs/telemetry.md
@@ -74,7 +74,11 @@ gemini --telemetry \
 ## Running an OTEL Collector
 
 An OTEL Collector is a service that receives, processes, and exports telemetry data.
-The CLI sends data using the OTLP/gRPC protocol.
+The CLI can send data using either the OTLP/gRPC or OTLP/HTTP protocol.
+You can specify which protocol to use via the `--telemetry-otlp-protocol` flag
+or the `telemetry.otlpProtocol` setting in your `settings.json` file. See the
+[configuration docs](./cli/configuration.md#--telemetry-otlp-protocol) for more
+details.
 
 Learn more about OTEL exporter standard configuration in [documentation][otel-config-docs].
 
diff --git a/package-lock.json b/package-lock.json
index a85be05e..7052ae8d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1626,6 +1626,25 @@
         "@opentelemetry/api": "^1.0.0"
       }
     },
+    "node_modules/@opentelemetry/exporter-logs-otlp-http": {
+      "version": "0.52.1",
+      "resolved": "https://registry.npmjs.org/@opentelemetry/exporter-logs-otlp-http/-/exporter-logs-otlp-http-0.52.1.tgz",
+      "integrity": "sha512-qKgywId2DbdowPZpOBXQKp0B8DfhfIArmSic15z13Nk/JAOccBUQdPwDjDnjsM5f0ckZFMVR2t/tijTUAqDZoA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@opentelemetry/api-logs": "0.52.1",
+        "@opentelemetry/core": "1.25.1",
+        "@opentelemetry/otlp-exporter-base": "0.52.1",
+        "@opentelemetry/otlp-transformer": "0.52.1",
+        "@opentelemetry/sdk-logs": "0.52.1"
+      },
+      "engines": {
+        "node": ">=14"
+      },
+      "peerDependencies": {
+        "@opentelemetry/api": "^1.0.0"
+      }
+    },
     "node_modules/@opentelemetry/exporter-metrics-otlp-grpc": {
       "version": "0.52.1",
       "resolved": "https://registry.npmjs.org/@opentelemetry/exporter-metrics-otlp-grpc/-/exporter-metrics-otlp-grpc-0.52.1.tgz",
@@ -12496,8 +12515,11 @@
         "@modelcontextprotocol/sdk": "^1.11.0",
         "@opentelemetry/api": "^1.9.0",
         "@opentelemetry/exporter-logs-otlp-grpc": "^0.52.0",
+        "@opentelemetry/exporter-logs-otlp-http": "^0.52.0",
         "@opentelemetry/exporter-metrics-otlp-grpc": "^0.52.0",
+        "@opentelemetry/exporter-metrics-otlp-http": "^0.52.0",
         "@opentelemetry/exporter-trace-otlp-grpc": "^0.52.0",
+        "@opentelemetry/exporter-trace-otlp-http": "^0.52.0",
         "@opentelemetry/instrumentation-http": "^0.52.0",
         "@opentelemetry/sdk-node": "^0.52.0",
         "@types/glob": "^8.1.0",
diff --git a/packages/cli/src/config/config.test.ts b/packages/cli/src/config/config.test.ts
index e4535fca..e70fc3b3 100644
--- a/packages/cli/src/config/config.test.ts
+++ b/packages/cli/src/config/config.test.ts
@@ -536,6 +536,60 @@ describe('loadCliConfig telemetry', () => {
     const config = await loadCliConfig(settings, [], 'test-session', argv);
     expect(config.getTelemetryLogPromptsEnabled()).toBe(true);
   });
+
+  it('should use telemetry OTLP protocol from settings if CLI flag is not present', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments();
+    const settings: Settings = {
+      telemetry: { otlpProtocol: 'http' },
+    };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getTelemetryOtlpProtocol()).toBe('http');
+  });
+
+  it('should prioritize --telemetry-otlp-protocol CLI flag over settings', async () => {
+    process.argv = ['node', 'script.js', '--telemetry-otlp-protocol', 'http'];
+    const argv = await parseArguments();
+    const settings: Settings = {
+      telemetry: { otlpProtocol: 'grpc' },
+    };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getTelemetryOtlpProtocol()).toBe('http');
+  });
+
+  it('should use default protocol if no OTLP protocol is provided via CLI or settings', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments();
+    const settings: Settings = { telemetry: { enabled: true } };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getTelemetryOtlpProtocol()).toBe('grpc');
+  });
+
+  it('should reject invalid --telemetry-otlp-protocol values', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--telemetry-otlp-protocol',
+      'invalid',
+    ];
+
+    const mockExit = vi.spyOn(process, 'exit').mockImplementation(() => {
+      throw new Error('process.exit called');
+    });
+
+    const mockConsoleError = vi
+      .spyOn(console, 'error')
+      .mockImplementation(() => {});
+
+    await expect(parseArguments()).rejects.toThrow('process.exit called');
+
+    expect(mockConsoleError).toHaveBeenCalledWith(
+      expect.stringContaining('Invalid values:'),
+    );
+
+    mockExit.mockRestore();
+    mockConsoleError.mockRestore();
+  });
 });
 
 describe('Hierarchical Memory Loading (config.ts) - Placeholder Suite', () => {
diff --git a/packages/cli/src/config/config.ts b/packages/cli/src/config/config.ts
index f50cafd4..a943f641 100644
--- a/packages/cli/src/config/config.ts
+++ b/packages/cli/src/config/config.ts
@@ -64,6 +64,7 @@ export interface CliArgs {
   checkpointing: boolean | undefined;
   telemetryTarget: string | undefined;
   telemetryOtlpEndpoint: string | undefined;
+  telemetryOtlpProtocol: string | undefined;
   telemetryLogPrompts: boolean | undefined;
   telemetryOutfile: string | undefined;
   allowedMcpServerNames: string[] | undefined;
@@ -172,6 +173,12 @@ export async function parseArguments(): Promise<CliArgs> {
           description:
             'Set the OTLP endpoint for telemetry. Overrides environment variables and settings files.',
         })
+        .option('telemetry-otlp-protocol', {
+          type: 'string',
+          choices: ['grpc', 'http'],
+          description:
+            'Set the OTLP protocol for telemetry (grpc or http). Overrides settings files.',
+        })
         .option('telemetry-log-prompts', {
           type: 'boolean',
           description:
@@ -491,6 +498,11 @@ export async function loadCliConfig(
         argv.telemetryOtlpEndpoint ??
         process.env.OTEL_EXPORTER_OTLP_ENDPOINT ??
         settings.telemetry?.otlpEndpoint,
+      otlpProtocol: (['grpc', 'http'] as const).find(
+        (p) =>
+          p ===
+          (argv.telemetryOtlpProtocol ?? settings.telemetry?.otlpProtocol),
+      ),
       logPrompts: argv.telemetryLogPrompts ?? settings.telemetry?.logPrompts,
       outfile: argv.telemetryOutfile ?? settings.telemetry?.outfile,
     },
diff --git a/packages/core/package.json b/packages/core/package.json
index 6f670f2c..0fc02e7b 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -24,8 +24,11 @@
     "@modelcontextprotocol/sdk": "^1.11.0",
     "@opentelemetry/api": "^1.9.0",
     "@opentelemetry/exporter-logs-otlp-grpc": "^0.52.0",
+    "@opentelemetry/exporter-logs-otlp-http": "^0.52.0",
     "@opentelemetry/exporter-metrics-otlp-grpc": "^0.52.0",
+    "@opentelemetry/exporter-metrics-otlp-http": "^0.52.0",
     "@opentelemetry/exporter-trace-otlp-grpc": "^0.52.0",
+    "@opentelemetry/exporter-trace-otlp-http": "^0.52.0",
     "@opentelemetry/instrumentation-http": "^0.52.0",
     "@opentelemetry/sdk-node": "^0.52.0",
     "@types/glob": "^8.1.0",
diff --git a/packages/core/src/config/config.test.ts b/packages/core/src/config/config.test.ts
index f1d8b965..3fb71ae8 100644
--- a/packages/core/src/config/config.test.ts
+++ b/packages/core/src/config/config.test.ts
@@ -567,5 +567,30 @@ describe('Server Config (config.ts)', () => {
       const config = new Config(paramsWithoutTelemetry);
       expect(config.getTelemetryOtlpEndpoint()).toBe(DEFAULT_OTLP_ENDPOINT);
     });
+
+    it('should return provided OTLP protocol', () => {
+      const params: ConfigParameters = {
+        ...baseParams,
+        telemetry: { enabled: true, otlpProtocol: 'http' },
+      };
+      const config = new Config(params);
+      expect(config.getTelemetryOtlpProtocol()).toBe('http');
+    });
+
+    it('should return default OTLP protocol if not provided', () => {
+      const params: ConfigParameters = {
+        ...baseParams,
+        telemetry: { enabled: true },
+      };
+      const config = new Config(params);
+      expect(config.getTelemetryOtlpProtocol()).toBe('grpc');
+    });
+
+    it('should return default OTLP protocol if telemetry object is not provided', () => {
+      const paramsWithoutTelemetry: ConfigParameters = { ...baseParams };
+      delete paramsWithoutTelemetry.telemetry;
+      const config = new Config(paramsWithoutTelemetry);
+      expect(config.getTelemetryOtlpProtocol()).toBe('grpc');
+    });
   });
 });
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index 5c11667b..49f9ab45 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -81,6 +81,7 @@ export interface TelemetrySettings {
   enabled?: boolean;
   target?: TelemetryTarget;
   otlpEndpoint?: string;
+  otlpProtocol?: 'grpc' | 'http';
   logPrompts?: boolean;
   outfile?: string;
 }
@@ -292,6 +293,7 @@ export class Config {
       enabled: params.telemetry?.enabled ?? false,
       target: params.telemetry?.target ?? DEFAULT_TELEMETRY_TARGET,
       otlpEndpoint: params.telemetry?.otlpEndpoint ?? DEFAULT_OTLP_ENDPOINT,
+      otlpProtocol: params.telemetry?.otlpProtocol,
       logPrompts: params.telemetry?.logPrompts ?? true,
       outfile: params.telemetry?.outfile,
     };
@@ -564,6 +566,10 @@ export class Config {
     return this.telemetrySettings.otlpEndpoint ?? DEFAULT_OTLP_ENDPOINT;
   }
 
+  getTelemetryOtlpProtocol(): 'grpc' | 'http' {
+    return this.telemetrySettings.otlpProtocol ?? 'grpc';
+  }
+
   getTelemetryTarget(): TelemetryTarget {
     return this.telemetrySettings.target ?? DEFAULT_TELEMETRY_TARGET;
   }
diff --git a/packages/core/src/telemetry/sdk.test.ts b/packages/core/src/telemetry/sdk.test.ts
new file mode 100644
index 00000000..a583bc38
--- /dev/null
+++ b/packages/core/src/telemetry/sdk.test.ts
@@ -0,0 +1,104 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { Config } from '../config/config.js';
+import { initializeTelemetry, shutdownTelemetry } from './sdk.js';
+import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-grpc';
+import { OTLPLogExporter } from '@opentelemetry/exporter-logs-otlp-grpc';
+import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-grpc';
+import { OTLPTraceExporter as OTLPTraceExporterHttp } from '@opentelemetry/exporter-trace-otlp-http';
+import { OTLPLogExporter as OTLPLogExporterHttp } from '@opentelemetry/exporter-logs-otlp-http';
+import { OTLPMetricExporter as OTLPMetricExporterHttp } from '@opentelemetry/exporter-metrics-otlp-http';
+import { NodeSDK } from '@opentelemetry/sdk-node';
+
+vi.mock('@opentelemetry/exporter-trace-otlp-grpc');
+vi.mock('@opentelemetry/exporter-logs-otlp-grpc');
+vi.mock('@opentelemetry/exporter-metrics-otlp-grpc');
+vi.mock('@opentelemetry/exporter-trace-otlp-http');
+vi.mock('@opentelemetry/exporter-logs-otlp-http');
+vi.mock('@opentelemetry/exporter-metrics-otlp-http');
+vi.mock('@opentelemetry/sdk-node');
+
+describe('Telemetry SDK', () => {
+  let mockConfig: Config;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockConfig = {
+      getTelemetryEnabled: () => true,
+      getTelemetryOtlpEndpoint: () => 'http://localhost:4317',
+      getTelemetryOtlpProtocol: () => 'grpc',
+      getTelemetryOutfile: () => undefined,
+      getDebugMode: () => false,
+      getSessionId: () => 'test-session',
+    } as unknown as Config;
+  });
+
+  afterEach(async () => {
+    await shutdownTelemetry(mockConfig);
+  });
+
+  it('should use gRPC exporters when protocol is grpc', () => {
+    initializeTelemetry(mockConfig);
+
+    expect(OTLPTraceExporter).toHaveBeenCalledWith({
+      url: 'http://localhost:4317',
+      compression: 'gzip',
+    });
+    expect(OTLPLogExporter).toHaveBeenCalledWith({
+      url: 'http://localhost:4317',
+      compression: 'gzip',
+    });
+    expect(OTLPMetricExporter).toHaveBeenCalledWith({
+      url: 'http://localhost:4317',
+      compression: 'gzip',
+    });
+    expect(NodeSDK.prototype.start).toHaveBeenCalled();
+  });
+
+  it('should use HTTP exporters when protocol is http', () => {
+    vi.spyOn(mockConfig, 'getTelemetryEnabled').mockReturnValue(true);
+    vi.spyOn(mockConfig, 'getTelemetryOtlpProtocol').mockReturnValue('http');
+    vi.spyOn(mockConfig, 'getTelemetryOtlpEndpoint').mockReturnValue(
+      'http://localhost:4318',
+    );
+
+    initializeTelemetry(mockConfig);
+
+    expect(OTLPTraceExporterHttp).toHaveBeenCalledWith({
+      url: 'http://localhost:4318/',
+    });
+    expect(OTLPLogExporterHttp).toHaveBeenCalledWith({
+      url: 'http://localhost:4318/',
+    });
+    expect(OTLPMetricExporterHttp).toHaveBeenCalledWith({
+      url: 'http://localhost:4318/',
+    });
+    expect(NodeSDK.prototype.start).toHaveBeenCalled();
+  });
+
+  it('should parse gRPC endpoint correctly', () => {
+    vi.spyOn(mockConfig, 'getTelemetryOtlpEndpoint').mockReturnValue(
+      'https://my-collector.com',
+    );
+    initializeTelemetry(mockConfig);
+    expect(OTLPTraceExporter).toHaveBeenCalledWith(
+      expect.objectContaining({ url: 'https://my-collector.com' }),
+    );
+  });
+
+  it('should parse HTTP endpoint correctly', () => {
+    vi.spyOn(mockConfig, 'getTelemetryOtlpProtocol').mockReturnValue('http');
+    vi.spyOn(mockConfig, 'getTelemetryOtlpEndpoint').mockReturnValue(
+      'https://my-collector.com',
+    );
+    initializeTelemetry(mockConfig);
+    expect(OTLPTraceExporterHttp).toHaveBeenCalledWith(
+      expect.objectContaining({ url: 'https://my-collector.com/' }),
+    );
+  });
+});
diff --git a/packages/core/src/telemetry/sdk.ts b/packages/core/src/telemetry/sdk.ts
index c6630236..3fbecaa9 100644
--- a/packages/core/src/telemetry/sdk.ts
+++ b/packages/core/src/telemetry/sdk.ts
@@ -8,6 +8,9 @@ import { DiagConsoleLogger, DiagLogLevel, diag } from '@opentelemetry/api';
 import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-grpc';
 import { OTLPLogExporter } from '@opentelemetry/exporter-logs-otlp-grpc';
 import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-grpc';
+import { OTLPTraceExporter as OTLPTraceExporterHttp } from '@opentelemetry/exporter-trace-otlp-http';
+import { OTLPLogExporter as OTLPLogExporterHttp } from '@opentelemetry/exporter-logs-otlp-http';
+import { OTLPMetricExporter as OTLPMetricExporterHttp } from '@opentelemetry/exporter-metrics-otlp-http';
 import { CompressionAlgorithm } from '@opentelemetry/otlp-exporter-base';
 import { NodeSDK } from '@opentelemetry/sdk-node';
 import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
@@ -45,8 +48,9 @@ export function isTelemetrySdkInitialized(): boolean {
   return telemetryInitialized;
 }
 
-function parseGrpcEndpoint(
+function parseOtlpEndpoint(
   otlpEndpointSetting: string | undefined,
+  protocol: 'grpc' | 'http',
 ): string | undefined {
   if (!otlpEndpointSetting) {
     return undefined;
@@ -56,9 +60,13 @@ function parseGrpcEndpoint(
 
   try {
     const url = new URL(trimmedEndpoint);
-    // OTLP gRPC exporters expect an endpoint in the format scheme://host:port
-    // The `origin` property provides this, stripping any path, query, or hash.
-    return url.origin;
+    if (protocol === 'grpc') {
+      // OTLP gRPC exporters expect an endpoint in the format scheme://host:port
+      // The `origin` property provides this, stripping any path, query, or hash.
+      return url.origin;
+    }
+    // For http, use the full href.
+    return url.href;
   } catch (error) {
     diag.error('Invalid OTLP endpoint URL provided:', trimmedEndpoint, error);
     return undefined;
@@ -77,43 +85,70 @@ export function initializeTelemetry(config: Config): void {
   });
 
   const otlpEndpoint = config.getTelemetryOtlpEndpoint();
-  const grpcParsedEndpoint = parseGrpcEndpoint(otlpEndpoint);
-  const useOtlp = !!grpcParsedEndpoint;
+  const otlpProtocol = config.getTelemetryOtlpProtocol();
+  const parsedEndpoint = parseOtlpEndpoint(otlpEndpoint, otlpProtocol);
+  const useOtlp = !!parsedEndpoint;
   const telemetryOutfile = config.getTelemetryOutfile();
 
-  const spanExporter = useOtlp
-    ? new OTLPTraceExporter({
-        url: grpcParsedEndpoint,
+  let spanExporter:
+    | OTLPTraceExporter
+    | OTLPTraceExporterHttp
+    | FileSpanExporter
+    | ConsoleSpanExporter;
+  let logExporter:
+    | OTLPLogExporter
+    | OTLPLogExporterHttp
+    | FileLogExporter
+    | ConsoleLogRecordExporter;
+  let metricReader: PeriodicExportingMetricReader;
+
+  if (useOtlp) {
+    if (otlpProtocol === 'http') {
+      spanExporter = new OTLPTraceExporterHttp({
+        url: parsedEndpoint,
+      });
+      logExporter = new OTLPLogExporterHttp({
+        url: parsedEndpoint,
+      });
+      metricReader = new PeriodicExportingMetricReader({
+        exporter: new OTLPMetricExporterHttp({
+          url: parsedEndpoint,
+        }),
+        exportIntervalMillis: 10000,
+      });
+    } else {
+      // grpc
+      spanExporter = new OTLPTraceExporter({
+        url: parsedEndpoint,
         compression: CompressionAlgorithm.GZIP,
-      })
-    : telemetryOutfile
-      ? new FileSpanExporter(telemetryOutfile)
-      : new ConsoleSpanExporter();
-  const logExporter = useOtlp
-    ? new OTLPLogExporter({
-        url: grpcParsedEndpoint,
+      });
+      logExporter = new OTLPLogExporter({
+        url: parsedEndpoint,
         compression: CompressionAlgorithm.GZIP,
-      })
-    : telemetryOutfile
-      ? new FileLogExporter(telemetryOutfile)
-      : new ConsoleLogRecordExporter();
-  const metricReader = useOtlp
-    ? new PeriodicExportingMetricReader({
+      });
+      metricReader = new PeriodicExportingMetricReader({
         exporter: new OTLPMetricExporter({
-          url: grpcParsedEndpoint,
+          url: parsedEndpoint,
           compression: CompressionAlgorithm.GZIP,
         }),
         exportIntervalMillis: 10000,
-      })
-    : telemetryOutfile
-      ? new PeriodicExportingMetricReader({
-          exporter: new FileMetricExporter(telemetryOutfile),
-          exportIntervalMillis: 10000,
-        })
-      : new PeriodicExportingMetricReader({
-          exporter: new ConsoleMetricExporter(),
-          exportIntervalMillis: 10000,
-        });
+      });
+    }
+  } else if (telemetryOutfile) {
+    spanExporter = new FileSpanExporter(telemetryOutfile);
+    logExporter = new FileLogExporter(telemetryOutfile);
+    metricReader = new PeriodicExportingMetricReader({
+      exporter: new FileMetricExporter(telemetryOutfile),
+      exportIntervalMillis: 10000,
+    });
+  } else {
+    spanExporter = new ConsoleSpanExporter();
+    logExporter = new ConsoleLogRecordExporter();
+    metricReader = new PeriodicExportingMetricReader({
+      exporter: new ConsoleMetricExporter(),
+      exportIntervalMillis: 10000,
+    });
+  }
 
   sdk = new NodeSDK({
     resource,