Meta-agent: self-improving agent harnesses from live traces
We built meta-agent: an open-source library that automatically and continuously improves agent harnesses from production traces. Point it at an existing agent, a stream of unlabeled production traces, and a small labeled holdout set. An LLM judge scores unlabeled production traces as they stream. A proposer reads failed traces and writes one targeted harness update at a time, such as changes to prompts, hooks, tools, or subagents. The update is kept only if it improves holdout accuracy. On tau-bench v3 airline, meta-agent improved holdout accuracy from 67% to 87%. We open-sourced meta-agent.…
In plain words
Meta-agent is an open-source library that automatically improves AI agents by analyzing production traces. Users point it at an existing agent, provide a stream of unlabeled production data, and a small labeled test set. An LLM judge scores the unlabeled traces while a proposer generates targeted updates to prompts, tools, hooks, or subagents, keeping only changes that improve accuracy. The library currently supports Claude Agent SDK with plans for additional frameworks. It demonstrated a 20-point accuracy improvement on a benchmark airline task.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
We built meta-agent: an open-source library that automatically and continuously improves agent harnesses from production traces. Point it at an existing agent, a stream of unlabeled production traces, and a small labeled holdout set. An LLM judge scores unlabeled production traces as they stream. A proposer reads failed traces and writes one targeted harness update at a time, such as changes to prompts, hooks, tools, or subagents. The update is kept only if it improves holdout accuracy. On tau-bench v3 airline, meta-agent improved holdout accuracy from 67% to 87%. We open-sourced meta-agent. It currently supports Claude Agent SDK, with more frameworks coming soon. Try it here: https://github.com/canvas-org/meta-agent
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