// python sdk
Python SDK
Add observability, fork & replay, and runtime safety to any Python agent with one decorator and a small, dependency-light package (Python 3.10+).
One decorator
Decorate your agent function with @retrace.record and the whole run is captured — there's no manual instrumentation to write.
Automatic capture
Calls to the major model providers are recorded for you, including prompts, responses, token usage, and cost.
Replay-ready
Mark a run resumable=True to unlock cascade fork & replay from the dashboard later.
Multi-agent tagging
Scope spans to an agent with retrace.agent(id, role=...) so multi-agent runs build a topology graph.
Safe by default
Privacy redaction is on, an offline buffer flushes on reconnect, and typed errors — auth, credits, rate-limit, enforcement — never crash your agent.
Built-in enforcement & cassettes
Local per-run ceilings raise a typed RetraceEnforcementError instead of overspending, and write_golden_cassette records a run as a CI fixture.
pip install retrace-sdkInstall from PyPI.
import retrace
retrace.configure(api_key="rt_...")
@retrace.record(name="support-agent", resumable=True)
def run_agent(prompt: str) -> str:
return agent.invoke(prompt)Configure once, then record any function with a decorator.
with retrace.agent("researcher", role="research"):
findings = research_agent.run(task)
with retrace.agent("writer", role="writer", parent="researcher"):
draft = writer_agent.run(findings)Tag each agent's work to build the topology graph.