Setup Install the Braintrust SDK and Strands, then set your API keys. The examples below use OpenAI. ```bash uv theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}} uv add braintrust "strands-agents[openai]" strands-agents-tools ``` ```bash pip theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}} pip install braintrust "strands-agents[openai]" strands-agents-tools ``` ```bash title=".env" theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}} BRAINTRUST_API_KEY= OPENAI_API_KEY= ``` Auto-instrumentation To trace Strands alongside Braintrust’s other supported libraries, call `braintrust.auto_instrument()` before creating your agent. ```python Python theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}} import os import braintrust from strands import Agent, tool from strands.models.openai import OpenAIModel braintrust.auto_instrument() braintrust.init_logger( api_key=os.environ["BRAINTRUST_API_KEY"], project="strands-example", # Replace with your project name ) @tool def current_weather(city: str) -> str: """Return the current weather for a city.""" return f"It is sunny in {city}." model = OpenAIModel( model_id="gpt-4o-mini", client_args={"api_key": os.environ["OPENAI_API_KEY"]}, ) agent = Agent( system_prompt="You answer weather questions concisely.", tools=[current_weather], model=model, ) result = agent("What is the weather in San Francisco?") print(result) ``` To trace Strands without auto-instrumenting other libraries, use `setup_strands()` instead of `braintrust.auto_instrument()`. ```python Python theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}} import os from braintrust.integrations.strands import setup_strands from strands import Agent, tool from strands.models.openai import OpenAIModel setup_strands(project_name="strands-example") @tool def current_weather(city: str) -> str: """Return the current weather for a city.""" return f"It is sunny in {city}." model = OpenAIModel( model_id="gpt-4o-mini", client_args={"api_key": os.environ["OPENAI_API_KEY"]}, ) agent = Agent( system_prompt="You answer weather questions concisely.", tools=[current_weather], model=model, ) print(agent("What is the weather in San Francisco?")) ``` Already running Strands with `StrandsTelemetry` or an OTLP exporter? Keep that setup and route spans to Braintrust using the [Braintrust OpenTelemetry guide](/integrations/sdk-integrations/opentelemetry#python-sdk-configuration). What Braintrust traces Braintrust mirrors Strands’ native span tree, so the trace shape matches the agent’s actual execution. Captured spans: * Agent invocation spans (`.invoke`), with input messages, agent name, model ID, and tool definitions; output stop reason, final message, and structured output. * Event loop cycle spans (`event_loop.cycle`), with input messages and cycle ID; output message and tool result message. * Model call spans (`.chat`), with input messages, system prompt, and model ID; output message, stop reason, and per-call token usage. * Tool call spans (`.execute`), with tool definition as input; output, execution status, and errors. * Parent-child nesting that mirrors Strands’ span hierarchy and nests under any enclosing Braintrust span. Resources * [Strands Agent SDK documentation](https://strandsagents.com/) * [Braintrust Python SDK reference](/reference/sdks/python/latest) * [Braintrust OpenTelemetry guide](/integrations/sdk-integrations/opentelemetry)