Anthropic Integration¶

Auto-trace Anthropic API calls and use Claude as an evaluation judge.

import "github.com/agentplexus/go-opik/integrations/anthropic"

Auto-Tracing¶

Tracing HTTP Client¶

Wrap HTTP calls to automatically create spans:

opikClient, _ := opik.NewClient()

// Create tracing HTTP client
httpClient := anthropic.TracingHTTPClient(opikClient)

// Use with your Anthropic client

Tracing Provider¶

Create a complete tracing provider:

tracingProvider := anthropic.TracingProvider(opikClient,
    anthropic.WithModel("claude-sonnet-4-20250514"),
)

Wrap Existing Client¶

Add tracing to an existing HTTP client:

existingClient := &http.Client{Timeout: 60 * time.Second}
tracingClient := anthropic.Wrap(existingClient, opikClient)

What Gets Traced¶

Each API call creates a span with:

Field	Description
Type	`LLM`
Provider	`anthropic`
Model	Model name from request
Input	Request body (messages, system prompt)
Output	Response body (content, stop reason)
Metadata	Token usage (input_tokens, output_tokens), duration

Evaluation Provider¶

Use Claude as an LLM judge:

provider := anthropic.NewProvider(
    anthropic.WithAPIKey("your-api-key"),
    anthropic.WithModel("claude-sonnet-4-20250514"),
    anthropic.WithTemperature(0.0),
)

// Use with evaluation metrics
relevance := llm.NewAnswerRelevance(provider)
coherence := llm.NewCoherence(provider)

Provider Options¶

Option	Description
`WithAPIKey(key)`	Set API key (default: `ANTHROPIC_API_KEY` env)
`WithModel(model)`	Set model (default: `claude-sonnet-4-20250514`)
`WithBaseURL(url)`	Custom endpoint
`WithHTTPClient(client)`	Custom HTTP client
`WithTemperature(temp)`	Generation temperature
`WithMaxTokens(max)`	Maximum tokens

Complete Example¶

func main() {
    ctx := context.Background()

    // Create Opik client
    opikClient, _ := opik.NewClient()

    // Create tracing HTTP client
    httpClient := anthropic.TracingHTTPClient(opikClient)

    // Start a trace
    ctx, trace, _ := opik.StartTrace(ctx, opikClient, "claude-request")
    defer trace.End(ctx)

    // Make Anthropic API call
    req, _ := http.NewRequestWithContext(ctx, "POST",
        "https://api.anthropic.com/v1/messages",
        bytes.NewReader(requestBody))

    req.Header.Set("x-api-key", os.Getenv("ANTHROPIC_API_KEY"))
    req.Header.Set("anthropic-version", "2023-06-01")
    req.Header.Set("content-type", "application/json")

    // Call is automatically traced!
    resp, err := httpClient.Do(req)
    if err != nil {
        log.Fatal(err)
    }
    defer resp.Body.Close()

    // Process response...
}

Supported Operations¶

The integration traces these Anthropic API endpoints:

Endpoint	Span Name
`/v1/messages`	`anthropic.messages`
`/v1/complete`	`anthropic.complete`
Other	`anthropic.api`