tracepad

The Python package for Tracepad — LLM observability and evals in a single binary: traces, prompts, datasets and scores for LLM and agent applications, self-hosted.

It is a thin layer over the OpenTelemetry SDK: it owns no transport, no batching and no context propagation, and it wraps no provider client. Everything it does is reachable with opentelemetry-sdk and curl — this is the one line that points an application at the store, and the ten lines after it that a person writes the same way every time.

pip install tracepad

Python 3.10+. Two dependencies: opentelemetry-sdk and opentelemetry-exporter-otlp-proto-http.

Point an application at a store

import tracepad

tracepad.init()  # or init(host="http://localhost:4318", key="tp-sk-…")

TRACEPAD_URL and TRACEPAD_API_KEY are the two variables it reads; TRACEPAD_ENVIRONMENT, TRACEPAD_RELEASE and TRACEPAD_EXPORT_TIMEOUT are the ones it can also use. If the application already has a TracerProvider — FastAPI instrumentation, another SDK — init adds an exporter to it rather than replacing it.

Three lines

@tracepad.observe                      # a span, with the arguments and the return value
def answer(question: str) -> str:
    tracepad.update_trace(user_id="u-42", tags=["support"])

    with tracepad.generation("chat", model="gpt-4o-mini") as call:
        response = client.chat.completions.create(model="gpt-4o-mini", messages=…)
        call.end(response=response)    # model, usage, and the cost as charged

    tracepad.score("helpful", 1)       # against the trace in flight
    return response.choices[0].message.content

A prompt by label, cached for as long as the server says and served stale when the server is away:

support = tracepad.prompt("support-answer", label="production")
messages = support.compile(product="Tracepad")

What it does not do

No provider-client wrapper and no auto-instrumentation: OpenLLMetry and the OpenTelemetry GenAI instrumentations are the answer there, and they work because the transport is shared. No price table either — the cost recorded is the one the provider charged, and what cannot be read is not sent.

Full documentation: docs/sdk-python.md.

Apache-2.0.