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.…
Meta-agent: self-improving agent harnesses from live traces launched on April 6, 2026 with 14 votes, #1,096 of 21,248 launches that month and more than 90% of that year's launches.
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
Continual harness optimization. Contribute to canvas-org/meta-agent development by creating an account on GitHub.
Meta-Agent turns execution traces into persistent improvements to the system around a language model. It learns at two timescales: The base model remains frozen. Meta-Agent keeps what it learns in harness code and versioned proposer instructions, backed by an on-disk experience store. Research question: Can an agent improve both its harness and the process used to improve that harness? An agent is more than its model. The harness decides what context the model sees, which tools it can call, how it tracks state, when it checks its output, and when it stops. Meta-Agent treats that harness as an editable program. It runs the current harness, records task-level traces and outcomes, proposes a…from github.com
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…
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