docs: add Genkit integration

content/integrations/frameworks/genkit.mdx

@@ -0,0 +1,121 @@
+---
+title: Trace Genkit with Langfuse via OpenTelemetry
+sidebarTitle: Genkit
+logo: /images/integrations/genkit_icon.svg
+description: Learn how to send Genkit traces to Langfuse from Go applications using OpenTelemetry.
+category: Integrations
+---
+
+# Trace Genkit with Langfuse
+
+Langfuse can ingest Genkit traces via OpenTelemetry. Once your Genkit application exports OTLP spans, Langfuse maps Genkit spans into traces and observations with model input, output, and usage data when available.
+
+> **What is Genkit?** [Genkit](https://genkit.dev/) is an open-source framework for building AI features and agentic workflows with structured flows, tool calling, and model integrations.
+
+> **What is Langfuse?** [Langfuse](https://langfuse.com/) is an open-source LLM engineering platform for observability, prompt management, and evals.
+
+<Callout type="info" emoji="ℹ️">
+This Langfuse integration is OpenTelemetry-based, not Go-specific. If your Genkit setup already exports OTLP traces, you can point that exporter at Langfuse. For Genkit Go, the common setup is the [Genkit OpenTelemetry plugin](https://github.com/genkit-ai/opentelemetry-go-plugin?tab=readme-ov-file#langfuse).
+</Callout>
+
+<Steps>
+## Step 1: Install the Genkit OpenTelemetry plugin
+
+```bash
+go get github.com/xavidop/genkit-opentelemetry-go
+```
+
+The package is documented in the [`genkit-ai/opentelemetry-go-plugin` repository](https://github.com/genkit-ai/opentelemetry-go-plugin).
+
+## Step 2: Configure Langfuse credentials
+
+```bash
+export LANGFUSE_BASE_URL="https://cloud.langfuse.com" # 🇪🇺 EU region
+# export LANGFUSE_BASE_URL="https://us.cloud.langfuse.com" # 🇺🇸 US region
+
+export LANGFUSE_PUBLIC_KEY="pk-lf-..."
+export LANGFUSE_SECRET_KEY="sk-lf-..."
+```
+
+## Step 3: Initialize the OpenTelemetry plugin
+
+Configure the plugin to send OTLP/HTTP traces to your Langfuse instance. Langfuse currently accepts OTLP over HTTP, so set `OTLPUseHTTP: true`. The example below disables metrics export because this setup is only sending traces to Langfuse.
+
+```go
+package main
+
+import (
+    "context"
+    "encoding/base64"
+    "fmt"
+    "log"
+    "os"
+
+    "github.com/firebase/genkit/go/genkit"
+    opentelemetry "github.com/xavidop/genkit-opentelemetry-go"
+)
+
+func main() {
+    baseURL := os.Getenv("LANGFUSE_BASE_URL")
+    if baseURL == "" {
+        baseURL = "https://cloud.langfuse.com"
+    }
+
+    publicKey := os.Getenv("LANGFUSE_PUBLIC_KEY")
+    secretKey := os.Getenv("LANGFUSE_SECRET_KEY")
+    if publicKey == "" || secretKey == "" {
+        log.Fatal("LANGFUSE_PUBLIC_KEY and LANGFUSE_SECRET_KEY must be set")
+    }
+
+    auth := base64.StdEncoding.EncodeToString([]byte(publicKey + ":" + secretKey))
+
+    plugin := opentelemetry.New(opentelemetry.Config{
+        ServiceName:            "my-genkit-app",
+        ForceExport:            true,
+        DisableMetricsExporter: true,
+        OTLPEndpoint:           baseURL + "/api/public/otel/v1/traces",
+        OTLPUseHTTP:            true,
+        OTLPHeaders: map[string]string{
+            "Authorization":                "Basic " + auth,
+            "X-Langfuse-Ingestion-Version": "4",
+        },
+    })
+
+    genkit.Init(
+        context.Background(),
+        genkit.WithPlugins(plugin),
+    )
+}
+```
+
+## Step 4: Run your Genkit flows
+
+After initializing the plugin, Genkit flows and model calls emit OpenTelemetry spans. Langfuse ingests those spans and displays them as traces with nested observations, including inputs, outputs, tool calls, and token usage when Genkit provides that metadata.
+
+If you already use an OpenTelemetry Collector, you can route Genkit spans through the Collector and export them to Langfuse from there. For endpoint and authentication details, see the [Langfuse OpenTelemetry guide](/integrations/native/opentelemetry).
+
+## Step 5: View traces in Langfuse
+
+Open **Traces** in Langfuse to inspect flow executions, model calls, latency, cost, and errors. If traces do not show up in local development, double-check `ForceExport: true`, the OTLP endpoint, and the Basic Auth credentials.
+
+![Genkit trace in Langfuse](/images/cookbook/integration-genkit/genkit-example-trace.png)
+</Steps>
+
+## Troubleshooting
+
+- **No traces appear in Langfuse**
+
+  - The Genkit OpenTelemetry plugin is initialized before your flows run.
+  - `OTLPUseHTTP` is set to `true`.
+  - The OTLP endpoint points to `https://<your-langfuse-host>/api/public/otel/v1/traces`.
+  - The `Authorization` header contains the Base64-encoded `public_key:secret_key` pair.
+  - If the `X-Langfuse-Ingestion-Version: 4` header is not set, traces may still ingest successfully but can take up to 10 minutes to appear in Langfuse.
+  - `ForceExport` is enabled in short-lived local processes so spans are flushed before the program exits.
+
+## Next Steps
+
+Once traces are flowing, you can use Langfuse to debug prompt inputs and outputs, add scores, and build dashboards on top of your Genkit workflows.
+
+import NextSteps from "@/components-mdx/get-started/next-steps.mdx";
+
+<NextSteps />

content/integrations/frameworks/meta.json

@@ -9,6 +9,7 @@
     "claude-agent-sdk-js",
     "crewai",
     "dspy",
+    "genkit",
     "google-adk",
     "haystack",
     "instructor",