feat: integrate Langfuse for LLM observability

- Add instrumentation.ts with Langfuse OpenTelemetry exporter - Enable experimental telemetry on streamText calls - Add instrumentationHook to Next.js config - Install required dependencies (@vercel/otel, langfuse-vercel, etc.)
2026-01-02 22:32:27 +08:00 · 2025-12-03 23:41:20 +09:00
parent 39322c2793
commit d84edb529c
5 changed files with 257 additions and 1 deletions
--- a/app/api/chat/route.ts
+++ b/app/api/chat/route.ts
@@ -257,6 +257,7 @@ ${lastMessageText}
      messages: [systemMessageWithCache, ...enhancedMessages],
      ...(providerOptions && { providerOptions }),
      ...(headers && { headers }),
+      experimental_telemetry: { isEnabled: true },
      onFinish: ({ usage, providerMetadata }) => {
        console.log('[Cache] Usage:', JSON.stringify({
          inputTokens: usage?.inputTokens,
--- a/instrumentation.ts
+++ b/instrumentation.ts
@@ -0,0 +1,9 @@
+import { registerOTel } from '@vercel/otel';
+import { LangfuseExporter } from 'langfuse-vercel';
+
+export function register() {
+  registerOTel({
+    serviceName: 'next-ai-draw-io',
+    traceExporter: new LangfuseExporter(),
+  });
+}
--- a/next.config.ts
+++ b/next.config.ts
@@ -3,6 +3,9 @@ import type { NextConfig } from "next";
 const nextConfig: NextConfig = {
  /* config options here */
  output: 'standalone',
+  experimental: {
+    instrumentationHook: true,
+  },
 };

 export default nextConfig;
--- a/package-lock.json
+++ b/package-lock.json
@@ -17,17 +17,22 @@
                "@ai-sdk/react": "^2.0.22",
                "@next/third-parties": "^16.0.6",
                "@openrouter/ai-sdk-provider": "^1.2.3",
+                "@opentelemetry/api-logs": "^0.208.0",
+                "@opentelemetry/instrumentation": "^0.208.0",
+                "@opentelemetry/sdk-logs": "^0.208.0",
                "@radix-ui/react-dialog": "^1.1.6",
                "@radix-ui/react-scroll-area": "^1.2.3",
                "@radix-ui/react-slot": "^1.1.2",
                "@radix-ui/react-tooltip": "^1.1.8",
                "@vercel/analytics": "^1.5.0",
+                "@vercel/otel": "^2.1.0",
                "@xmldom/xmldom": "^0.9.8",
                "ai": "^5.0.89",
                "base-64": "^1.0.0",
                "class-variance-authority": "^0.7.1",
                "clsx": "^2.1.1",
                "jsdom": "^26.0.0",
+                "langfuse-vercel": "^3.38.6",
                "lucide-react": "^0.483.0",
                "next": "15.2.3",
                "ollama-ai-provider-v2": "^1.5.4",
@@ -1860,6 +1865,127 @@
                "node": ">=8.0.0"
            }
        },
+        "node_modules/@opentelemetry/api-logs": {
+            "version": "0.208.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/api-logs/-/api-logs-0.208.0.tgz",
+            "integrity": "sha512-CjruKY9V6NMssL/T1kAFgzosF1v9o6oeN+aX5JB/C/xPNtmgIJqcXHG7fA82Ou1zCpWGl4lROQUKwUNE1pMCyg==",
+            "license": "Apache-2.0",
+            "dependencies": {
+                "@opentelemetry/api": "^1.3.0"
+            },
+            "engines": {
+                "node": ">=8.0.0"
+            }
+        },
+        "node_modules/@opentelemetry/core": {
+            "version": "2.2.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/core/-/core-2.2.0.tgz",
+            "integrity": "sha512-FuabnnUm8LflnieVxs6eP7Z383hgQU4W1e3KJS6aOG3RxWxcHyBxH8fDMHNgu/gFx/M2jvTOW/4/PHhLz6bjWw==",
+            "license": "Apache-2.0",
+            "dependencies": {
+                "@opentelemetry/semantic-conventions": "^1.29.0"
+            },
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": ">=1.0.0 <1.10.0"
+            }
+        },
+        "node_modules/@opentelemetry/instrumentation": {
+            "version": "0.208.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/instrumentation/-/instrumentation-0.208.0.tgz",
+            "integrity": "sha512-Eju0L4qWcQS+oXxi6pgh7zvE2byogAkcsVv0OjHF/97iOz1N/aKE6etSGowYkie+YA1uo6DNwdSxaaNnLvcRlA==",
+            "license": "Apache-2.0",
+            "dependencies": {
+                "@opentelemetry/api-logs": "0.208.0",
+                "import-in-the-middle": "^2.0.0",
+                "require-in-the-middle": "^8.0.0"
+            },
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": "^1.3.0"
+            }
+        },
+        "node_modules/@opentelemetry/resources": {
+            "version": "2.2.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/resources/-/resources-2.2.0.tgz",
+            "integrity": "sha512-1pNQf/JazQTMA0BiO5NINUzH0cbLbbl7mntLa4aJNmCCXSj0q03T5ZXXL0zw4G55TjdL9Tz32cznGClf+8zr5A==",
+            "license": "Apache-2.0",
+            "dependencies": {
+                "@opentelemetry/core": "2.2.0",
+                "@opentelemetry/semantic-conventions": "^1.29.0"
+            },
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": ">=1.3.0 <1.10.0"
+            }
+        },
+        "node_modules/@opentelemetry/sdk-logs": {
+            "version": "0.208.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/sdk-logs/-/sdk-logs-0.208.0.tgz",
+            "integrity": "sha512-QlAyL1jRpOeaqx7/leG1vJMp84g0xKP6gJmfELBpnI4O/9xPX+Hu5m1POk9Kl+veNkyth5t19hRlN6tNY1sjbA==",
+            "license": "Apache-2.0",
+            "dependencies": {
+                "@opentelemetry/api-logs": "0.208.0",
+                "@opentelemetry/core": "2.2.0",
+                "@opentelemetry/resources": "2.2.0"
+            },
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": ">=1.4.0 <1.10.0"
+            }
+        },
+        "node_modules/@opentelemetry/sdk-metrics": {
+            "version": "2.2.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/sdk-metrics/-/sdk-metrics-2.2.0.tgz",
+            "integrity": "sha512-G5KYP6+VJMZzpGipQw7Giif48h6SGQ2PFKEYCybeXJsOCB4fp8azqMAAzE5lnnHK3ZVwYQrgmFbsUJO/zOnwGw==",
+            "license": "Apache-2.0",
+            "peer": true,
+            "dependencies": {
+                "@opentelemetry/core": "2.2.0",
+                "@opentelemetry/resources": "2.2.0"
+            },
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": ">=1.9.0 <1.10.0"
+            }
+        },
+        "node_modules/@opentelemetry/sdk-trace-base": {
+            "version": "2.2.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/sdk-trace-base/-/sdk-trace-base-2.2.0.tgz",
+            "integrity": "sha512-xWQgL0Bmctsalg6PaXExmzdedSp3gyKV8mQBwK/j9VGdCDu2fmXIb2gAehBKbkXCpJ4HPkgv3QfoJWRT4dHWbw==",
+            "license": "Apache-2.0",
+            "peer": true,
+            "dependencies": {
+                "@opentelemetry/core": "2.2.0",
+                "@opentelemetry/resources": "2.2.0",
+                "@opentelemetry/semantic-conventions": "^1.29.0"
+            },
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": ">=1.3.0 <1.10.0"
+            }
+        },
+        "node_modules/@opentelemetry/semantic-conventions": {
+            "version": "1.38.0",
+            "resolved": "https://registry.npmjs.org/@opentelemetry/semantic-conventions/-/semantic-conventions-1.38.0.tgz",
+            "integrity": "sha512-kocjix+/sSggfJhwXqClZ3i9Y/MI0fp7b+g7kCRm6psy2dsf8uApTRclwG18h8Avm7C9+fnt+O36PspJ/OzoWg==",
+            "license": "Apache-2.0",
+            "engines": {
+                "node": ">=14"
+            }
+        },
        "node_modules/@radix-ui/number": {
            "version": "1.1.0",
            "resolved": "https://registry.npmjs.org/@radix-ui/number/-/number-1.1.0.tgz",
@@ -3398,6 +3524,24 @@
                "node": ">= 20"
            }
        },
+        "node_modules/@vercel/otel": {
+            "version": "2.1.0",
+            "resolved": "https://registry.npmjs.org/@vercel/otel/-/otel-2.1.0.tgz",
+            "integrity": "sha512-Zwu2Cu4t46DzBnY1DQSTxZ4MBLVfYsOjnlWuZuLRWnmVPX+SNrVHbs3ssiJ6uvY1J1JJswor4zSn8mHYxzYeBA==",
+            "license": "MIT",
+            "engines": {
+                "node": "^18.19.0 || >=20.6.0"
+            },
+            "peerDependencies": {
+                "@opentelemetry/api": ">=1.9.0 <2.0.0",
+                "@opentelemetry/api-logs": ">=0.200.0 <0.300.0",
+                "@opentelemetry/instrumentation": ">=0.200.0 <0.300.0",
+                "@opentelemetry/resources": ">=2.0.0 <3.0.0",
+                "@opentelemetry/sdk-logs": ">=0.200.0 <0.300.0",
+                "@opentelemetry/sdk-metrics": ">=2.0.0 <3.0.0",
+                "@opentelemetry/sdk-trace-base": ">=2.0.0 <3.0.0"
+            }
+        },
        "node_modules/@xmldom/xmldom": {
            "version": "0.9.8",
            "resolved": "https://registry.npmjs.org/@xmldom/xmldom/-/xmldom-0.9.8.tgz",
@@ -3411,7 +3555,6 @@
            "version": "8.15.0",
            "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.15.0.tgz",
            "integrity": "sha512-NZyJarBfL7nWwIq+FDL6Zp/yHEhePMNnnJ0y3qfieCrmNvYct8uvtiV41UvlSe6apAfk0fY1FbWx+NwfmpvtTg==",
-            "dev": true,
            "license": "MIT",
            "bin": {
                "acorn": "bin/acorn"
@@ -3420,6 +3563,15 @@
                "node": ">=0.4.0"
            }
        },
+        "node_modules/acorn-import-attributes": {
+            "version": "1.9.5",
+            "resolved": "https://registry.npmjs.org/acorn-import-attributes/-/acorn-import-attributes-1.9.5.tgz",
+            "integrity": "sha512-n02Vykv5uA3eHGM/Z2dQrcD56kL8TyDb2p1+0P83PClMnC/nc+anbQRhIOWnSq4Ke/KvDPrY3C9hDtC/A3eHnQ==",
+            "license": "MIT",
+            "peerDependencies": {
+                "acorn": "^8"
+            }
+        },
        "node_modules/acorn-jsx": {
            "version": "5.3.2",
            "resolved": "https://registry.npmjs.org/acorn-jsx/-/acorn-jsx-5.3.2.tgz",
@@ -3962,6 +4114,12 @@
                "url": "https://github.com/sponsors/wooorm"
            }
        },
+        "node_modules/cjs-module-lexer": {
+            "version": "1.4.3",
+            "resolved": "https://registry.npmjs.org/cjs-module-lexer/-/cjs-module-lexer-1.4.3.tgz",
+            "integrity": "sha512-9z8TZaGM1pfswYeXrUpzPrkx8UnWYdhJclsiYMm6x/w5+nN+8Tf/LnAgfLGQCm59qAOxU8WwHEq2vNwF6i4j+Q==",
+            "license": "MIT"
+        },
        "node_modules/class-variance-authority": {
            "version": "0.7.1",
            "resolved": "https://registry.npmjs.org/class-variance-authority/-/class-variance-authority-0.7.1.tgz",
@@ -5576,6 +5734,18 @@
                "url": "https://github.com/sponsors/sindresorhus"
            }
        },
+        "node_modules/import-in-the-middle": {
+            "version": "2.0.0",
+            "resolved": "https://registry.npmjs.org/import-in-the-middle/-/import-in-the-middle-2.0.0.tgz",
+            "integrity": "sha512-yNZhyQYqXpkT0AKq3F3KLasUSK4fHvebNH5hOsKQw2dhGSALvQ4U0BqUc5suziKvydO5u5hgN2hy1RJaho8U5A==",
+            "license": "Apache-2.0",
+            "dependencies": {
+                "acorn": "^8.14.0",
+                "acorn-import-attributes": "^1.9.5",
+                "cjs-module-lexer": "^1.2.2",
+                "module-details-from-path": "^1.0.3"
+            }
+        },
        "node_modules/imurmurhash": {
            "version": "0.1.4",
            "resolved": "https://registry.npmjs.org/imurmurhash/-/imurmurhash-0.1.4.tgz",
@@ -6209,6 +6379,46 @@
                "json-buffer": "3.0.1"
            }
        },
+        "node_modules/langfuse": {
+            "version": "3.38.6",
+            "resolved": "https://registry.npmjs.org/langfuse/-/langfuse-3.38.6.tgz",
+            "integrity": "sha512-mtwfsNGIYvObRh+NYNGlJQJDiBN+Wr3Hnr++wN25mxuOpSTdXX+JQqVCyAqGL5GD2TAXRZ7COsN42Vmp9krYmg==",
+            "license": "MIT",
+            "dependencies": {
+                "langfuse-core": "^3.38.6"
+            },
+            "engines": {
+                "node": ">=18"
+            }
+        },
+        "node_modules/langfuse-core": {
+            "version": "3.38.6",
+            "resolved": "https://registry.npmjs.org/langfuse-core/-/langfuse-core-3.38.6.tgz",
+            "integrity": "sha512-EcZXa+DK9FJdi1I30+u19eKjuBJ04du6j2Nybk19KKCuraLczg/ppkTQcGvc4QOk//OAi3qUHrajUuV74RXsBQ==",
+            "license": "MIT",
+            "dependencies": {
+                "mustache": "^4.2.0"
+            },
+            "engines": {
+                "node": ">=18"
+            }
+        },
+        "node_modules/langfuse-vercel": {
+            "version": "3.38.6",
+            "resolved": "https://registry.npmjs.org/langfuse-vercel/-/langfuse-vercel-3.38.6.tgz",
+            "integrity": "sha512-QlKZC1RhZRUlI0zNvxP5B6P2Xtt1+1ADTQfC/3hlnXFT3BMJZMynI/eUN3VX7WbNRGK0yDpqA9PyylXQskr92Q==",
+            "license": "MIT",
+            "dependencies": {
+                "langfuse": "^3.38.6",
+                "langfuse-core": "^3.38.6"
+            },
+            "engines": {
+                "node": ">=18"
+            },
+            "peerDependencies": {
+                "ai": ">=3.2.44"
+            }
+        },
        "node_modules/language-subtag-registry": {
            "version": "0.3.23",
            "resolved": "https://registry.npmjs.org/language-subtag-registry/-/language-subtag-registry-0.3.23.tgz",
@@ -7382,12 +7592,27 @@
                "url": "https://github.com/sponsors/ljharb"
            }
        },
+        "node_modules/module-details-from-path": {
+            "version": "1.0.4",
+            "resolved": "https://registry.npmjs.org/module-details-from-path/-/module-details-from-path-1.0.4.tgz",
+            "integrity": "sha512-EGWKgxALGMgzvxYF1UyGTy0HXX/2vHLkw6+NvDKW2jypWbHpjQuj4UMcqQWXHERJhVGKikolT06G3bcKe4fi7w==",
+            "license": "MIT"
+        },
        "node_modules/ms": {
            "version": "2.1.3",
            "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
            "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
            "license": "MIT"
        },
+        "node_modules/mustache": {
+            "version": "4.2.0",
+            "resolved": "https://registry.npmjs.org/mustache/-/mustache-4.2.0.tgz",
+            "integrity": "sha512-71ippSywq5Yb7/tVYyGbkBggbU8H3u5Rz56fH60jGFgr8uHwxs+aSKeqmluIVzM0m0kB7xQjKS6qPfd0b2ZoqQ==",
+            "license": "MIT",
+            "bin": {
+                "mustache": "bin/mustache"
+            }
+        },
        "node_modules/nanoid": {
            "version": "3.3.11",
            "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.11.tgz",
@@ -8137,6 +8362,19 @@
                "url": "https://opencollective.com/unified"
            }
        },
+        "node_modules/require-in-the-middle": {
+            "version": "8.0.1",
+            "resolved": "https://registry.npmjs.org/require-in-the-middle/-/require-in-the-middle-8.0.1.tgz",
+            "integrity": "sha512-QT7FVMXfWOYFbeRBF6nu+I6tr2Tf3u0q8RIEjNob/heKY/nh7drD/k7eeMFmSQgnTtCzLDcCu/XEnpW2wk4xCQ==",
+            "license": "MIT",
+            "dependencies": {
+                "debug": "^4.3.5",
+                "module-details-from-path": "^1.0.3"
+            },
+            "engines": {
+                "node": ">=9.3.0 || >=8.10.0 <9.0.0"
+            }
+        },
        "node_modules/resolve": {
            "version": "1.22.11",
            "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.22.11.tgz",
--- a/package.json
+++ b/package.json
@@ -18,17 +18,22 @@
        "@ai-sdk/react": "^2.0.22",
        "@next/third-parties": "^16.0.6",
        "@openrouter/ai-sdk-provider": "^1.2.3",
+        "@opentelemetry/api-logs": "^0.208.0",
+        "@opentelemetry/instrumentation": "^0.208.0",
+        "@opentelemetry/sdk-logs": "^0.208.0",
        "@radix-ui/react-dialog": "^1.1.6",
        "@radix-ui/react-scroll-area": "^1.2.3",
        "@radix-ui/react-slot": "^1.1.2",
        "@radix-ui/react-tooltip": "^1.1.8",
        "@vercel/analytics": "^1.5.0",
+        "@vercel/otel": "^2.1.0",
        "@xmldom/xmldom": "^0.9.8",
        "ai": "^5.0.89",
        "base-64": "^1.0.0",
        "class-variance-authority": "^0.7.1",
        "clsx": "^2.1.1",
        "jsdom": "^26.0.0",
+        "langfuse-vercel": "^3.38.6",
        "lucide-react": "^0.483.0",
        "next": "15.2.3",
        "ollama-ai-provider-v2": "^1.5.4",