Paste an agent trajectory. fewwords auto-detects the format, renders the tool sequence, and runs deterministic contract checks.
See /prove for the incident catalogue.
Zero install. Supported formats: OpenAI messages,
LangGraph events, OTel spans, Anthropic tool-use, native fewwords.
Every computation below runs deterministically on your input, no
LLM-as-judge anywhere on this page.
Try one of these first
Your trace
Synthesis needs a reference corpus, we compare your trace against
4 preloaded good runs automatically.
What should have blocked this?
Describe a rule in plain English, one per line. We compile each
line to a deterministic check and hand you a YAML snippet to drop
into .trajeval.yml. Six supported patterns:
never call <tool>,
must call <tool>,
<A> before <B>,
whenever <A> then <B>,
max N tool calls,
cost under $X.
Pure regex → formal check. No LLM in the hot path.
Not ready to install today?
Leave an email and we'll ping you when PyPI ships, when the
LangGraph auto-hook lands, or when a major vertical template
drops. No marketing.