wrapOpenAI wrapper functions for automatic tracing, and proxy support.
This guide covers manual instrumentation. For quicker setup, use auto-instrumentation.
For the GPT-5 family of models, the
temperature parameter is not configurable. It is handled automatically by the model and is disabled in the Braintrust UI.Setup
To use OpenAI models in the Braintrust playground, API, and gateway, connect OpenAI as a provider in your organization or project AI providers.- Go to Settings > AI providers.
- Click Organization provider or Project provider, depending on whether you want the provider to be available across every project in the organization or just the current project.
- Under Model providers, click OpenAI.
-
Choose your authentication method:
-
API key: Visit OpenAI’s API platform, create a new API key, and paste it into the Secret field.
API keys are stored as one-way cryptographic hashes, never in plaintext.
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Workload identity federation: Exchange a Braintrust-signed OIDC token for an OpenAI access token, instead of storing a long-lived OpenAI API key in Braintrust.
Workload identity federation is available only for organization-level providers on Braintrust-hosted organizations with the Braintrust gateway enabled. Project-level providers and self-hosted deployments must use API key authentication.
-
API key: Visit OpenAI’s API platform, create a new API key, and paste it into the Secret field.
-
If you chose Workload identity federation, use the setup values shown in Braintrust to configure OpenAI:
- Create a workload identity provider in OpenAI. Use the Issuer URL and Audience shown in Braintrust, set JWKS source to OIDC discovery, use the Subject pattern, and add the Required claims shown in Braintrust.
- Map the workload identity provider to the OpenAI service account Braintrust should use.
- Paste the OpenAI IDs back into Braintrust:
- Identity provider ID: The workload identity provider ID configured for Braintrust.
- Service account ID: The OpenAI service account ID Braintrust should use.
- Subject suffix: A stable suffix for this OpenAI connection. It must match the final part of the subject pattern used in OpenAI.
- Click Save.
.env
braintrust and openai packages.
Trace with OpenAI
Trace your OpenAI LLM calls for observability and monitoring. Using the OpenAI Agents SDK? See the OpenAI Agents SDK framework docs.Trace automatically
Braintrust provides automatic tracing for OpenAI API calls, handling streaming, metrics collection, and other details.- TypeScript & Python: Use
wrapOpenAI/wrap_openaiwrapper functions - Go: Use the tracing middleware with the OpenAI client
- Ruby: Use
Braintrust::Trace::OpenAI.wrapto wrap the OpenAI client - Java: Use the tracing interceptor with the OpenAI client
- C#: Use
BraintrustOpenAI.WrapOpenAIto wrap the OpenAI client
Stream OpenAI responses
wrap_openai/wrapOpenAI can automatically log metrics like prompt_tokens, completion_tokens, and tokens for streaming LLM calls if the LLM API returns them. Set include_usage to true in the stream_options parameter to receive these metrics from OpenAI.
Evaluate with OpenAI
Evaluations help you distill the non-deterministic outputs of OpenAI models into an effective feedback loop that enables you to ship more reliable, higher quality products. BraintrustEval is a simple function composed of a dataset of user inputs, a task, and a set of scorers. To learn more about evaluations, see the Experiments guide.
Basic OpenAI eval setup
Evaluate the outputs of OpenAI models with Braintrust.Use OpenAI as an LLM judge
You can use OpenAI models to score the outputs of other AI systems. This example uses theLLMClassifierFromSpec scorer to score the relevance of the outputs of an AI system.
Install the autoevals package to use the LLMClassifierFromSpec scorer.
LLMClassifierFromSpec scorer to score the relevance of the outputs of an AI system. You can then include relevanceScorer as a scorer in your Eval function (see above).
Additional features
Structured outputs
OpenAI’s structured outputs are supported with the wrapper functions.Function calling and tools
Braintrust supports OpenAI function calling for building AI agents with tools.Streaming audio transcriptions
Braintrust traces streaming audio transcription calls for sync and async OpenAI clients. Each span captures the audio file as an attachment and the final transcript as the span output.Multimodal content, attachments, errors, and masking sensitive data
To learn more about these topics, check out the customize traces guide.Use OpenAI with Braintrust gateway
You can also access OpenAI models through the Braintrust gateway, which provides a unified interface for multiple providers. Use any supported provider’s SDK to call OpenAI models.Generate embeddings
The gateway also supports the OpenAI-compatible/embeddings endpoint for generating embeddings. See Generate embeddings for an example.