modelmri-record

Record what your agent actually did — LLM calls, tool calls, subagents, errors — and look at it on a timeline instead of scrolling logs.

pip install modelmri-record

Stdlib only. No torch, no numpy, no SDK pins. Instrumenting an agent shouldn't cost you a 2.5 GB install.

Use

from modelmri_record import trace, step

with trace("fix-failing-tests"):
    step("llm_call", name="plan", input=prompt, output=answer,
         duration_ms=1200, tokens_in=900, tokens_out=200)

    with step("subagent", name="test-runner"):
        step("tool_call", name="pytest", input="-q", output="3 failed")

Nesting is automatic — a step used as a context manager becomes the parent of everything recorded inside it, and its duration is measured for you.

Auto-instrument an SDK instead:

from modelmri_record import instrument_anthropic
instrument_anthropic()      # every Messages.create is now an llm_call step

Where traces go

POSTed to a running ModelMRI viewer on http://127.0.0.1:5900. If nothing is listening, they're written to ./modelmri-traces/*.json to import later — so you can record on a box that has no viewer and look at it somewhere else.

To view them: pip install modelmri && modelmri serve.

Credentials are redacted by default

Agent prompts routinely contain the key the agent was handed. A recorder that writes those to disk verbatim is a liability dressed as an observability feature, so redaction is on unless you switch it off:

with trace("run"):                      # default scrubber
with trace("run", redact=my_function)   # your own str -> str
with trace("run", redact=False)         # verbatim, deliberately

Covered: sk-…, hf_…, pypi-…, ghp_…/github_pat_…, xoxb-…, Google AIza…, AWS key ids, Bearer …, and whole PEM private-key blocks.

Patterns are deliberately narrow — known credential shapes, not "anything high-entropy". A redactor that eats hashes and UUIDs makes traces useless, and a useless trace gets the feature turned off, which protects nobody. Add your own shapes:

from modelmri_record.redact import make_redactor
red = make_redactor([r"ACME-[0-9]{6}"])

It will not take down your app

Recording is best-effort by contract. If the viewer is unreachable, the disk is read-only, or the payload won't serialise, it gives up quietly. A tracing library that can raise is one nobody leaves switched on.

Traces still open when the process exits are flushed by an atexit hook — a crash or a SIGTERM is exactly the run you most wanted to look at.

Licence

MIT. Part of ModelMRI.