Who is harnessgym for?

harnessgym is an open-source project built for AI researchers and developers.

Does harnessgym have a free plan?

Yes — harnessgym is open source under the Apache-2.0 license and free to use.

What platforms does harnessgym run on?

harnessgym runs on the command line. It can also be self-hosted.

Is harnessgym still active?

The GitHub repository shows 1 commit in the last 90 days.

What are alternatives to harnessgym?

Similar projects tracked by PulseGate include harness-arena, harness-baby, and godharness.

Who develops harnessgym?

harnessgym is developed by patrick-toulme.

When did harnessgym launch?

harnessgym first shipped in 2026.

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harnessgym

Name: harnessgym
Author: patrick-toulme

PyPIInfrastructure

harnessgym is an open-source CLI framework for benchmarking, testing, and improving agent harnesses for AI code agents such as Codex. It supports iterative improvement, MCP, and is designed for AI researchers and developers.

Open SourceApache-2.0CLISelf-hosted

Visit PyPI

25stars

3forks

6features

2026since

Overview

6 features

harnessgym is a LLM eval & observability project. It focuses on providing a framework for benchmarking and improving agent harnesses for AI code agents like Codex. harnessgym is an open-source project aimed at AI researchers and developers. harnessgym is open source under the Apache-2.0 license. harnessgym is available on the command line, and it can be self-hosted.

patrick-toulme builds and maintains harnessgym, and it first shipped in 2026. Development happens publicly on GitHub with 25 stars and 1 commit in the last 90 days. Among its 6 catalogued features are agent benchmarking, codex integration, and MCP support.

Summary written by a language model from the project’s public pages.

Agent benchmarking
Codex integration
MCP support
Testing framework
Open source
Iterative improvement

Built with & integrations

Runs on

CLISelf-hosted

Trust & compliance

License

Apache-2.0

Verified signals

HTTPSOpen SourceFree tierGitHub · ★ 25Active maintenance

Indexing history

What PulseGate has recorded for this listing

Indexed1 Jul · 02:25 UTC
harnessgym verified against its public source
Source: PulseGate · Open

Frequently asked questions about harnessgym

What is harnessgym?: Harnessgym focuses on providing a framework for benchmarking and improving agent harnesses for AI code agents like Codex. It is catalogued under LLM eval & observability on PulseGate.
Who is harnessgym for?: harnessgym is an open-source project built for AI researchers and developers.
Does harnessgym have a free plan?: Yes — harnessgym is open source under the Apache-2.0 license and free to use.
What platforms does harnessgym run on?: harnessgym runs on the command line. It can also be self-hosted.
Is harnessgym still active?: The GitHub repository shows 1 commit in the last 90 days.
What are alternatives to harnessgym?: Similar projects tracked by PulseGate include harness-arena, harness-baby, and godharness.harness-arena harness-baby godharness See all 20 alternatives
Who develops harnessgym?: harnessgym is developed by patrick-toulme.
When did harnessgym launch?: harnessgym first shipped in 2026.

At a glance

Platforms: CLI
Languages: English
Open source: Yes · ★ 25
License: Apache-2.0
First seen: 1 Jul 2026
Built for: AI researchers and developers
Model: Open source
Solves: Providing a framework for benchmarking and improving agent harnesses for AI code agents like Codex.

Registered as

GitHub: patrick-toulme/harnessgym
PyPI: harnessgym

Developer

patrick-toulme

Solo developer

GitHub

Open source

View on GitHub

Stars: 25
Forks: 3
Open issues: 5
Last commit: 29 Jun 2026
Commits 90d: 1
Contributors: 1
Authorship: Solo
Default branch: main

Index record

Indexed: 1 Jul 2026
Lifecycle: Alive
First seen: Jul 2026
Last seen: 1 Jul 2026

Identity audit (12)

Slug: harnessgym-pypi-org
Lifecycle last checked: 8 Aug 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 1 Jul 2026
Timeline basis: Indexed-at chronology (no inferred launch/funding milestones).
Name from: Written by a language model from the project's public pages.
Category from: Assigned by a language model.
Summary from: Written by a language model from public pages.
Languages from: Detected by a language model from page content.
Canonical URL: https://pypi.org/project/harnessgym

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