Skip to content
Agentmart
Submit a tool

pufferlib

Version-aware guidance for PufferLib reinforcement-learning environments, vectorization, policies, PuffeRL training, evaluation, and safe checkpoint review.

Skill by K-Dense-AI

IndexedMIT★ 54,411
Write a review

Chalk Labs

Need help deploying pufferlib?

Chalk Labs sets up agents like this inside real teams: connected to your tools, tested on your data, with a human in the loop where it matters.

Book a call

Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/k-dense-ai-pufferlib

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

Get the weekly diff

The weekly diff: one email a week with new agent tools, notable updates and grade changes, plus security alerts for tools you follow. Double opt-in, one-click unsubscribe.

We use your email only for this newsletter. Privacy

About

Version-aware guidance for PufferLib reinforcement-learning environments, vectorization, policies, PuffeRL training, evaluation, and safe checkpoint review. Covers the native 5.0 build and environment API, published 3.0.0 Gymnasium/PettingZoo adaptation, and a pinned historical 4.0 profile.

Use cases: backend

No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found
Runs as
Python package

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/pufferlib

Tools it pre-approves 4

From allowed-tools in SKILL.md: the agent may use these without asking you each time.

  • Read
  • Bash
  • Grep
  • Python

What's inside

Skill name
pufferlib
Description
Version-aware guidance for PufferLib reinforcement-learning environments, vectorization, policies, PuffeRL training, evaluation, and safe checkpoint review. Covers the native 5.0 build and environment API, published 3.0.0 Gymnasium/PettingZoo adaptation, and a pinned historical 4.0 profile.
License
MIT
Compatibility
Bundled CLIs require Python 3.10+ (standard library only). PufferLib 5.0 requires a native C/CUDA toolchain; CPU builds support evaluation, not training. PyPI 3.0.0 declares Python >=3.9 and needs a native source build with NumPy <2 and Gymnasium <=0.29.1. Native dependencies and network access are needed for installation; bundled checks require neither.
Allowed tools
Read, Bash, Grep, Python
Metadata
version: 1.4 · skill-author: K-Dense Inc. · last-reviewed: 2026-10-01
Instructions
376 lines in SKILL.md · view on GitHub

Before installing

  • Ships executable scripts
  • Pre-approves any shell command

Files (16)

  • SKILL.md
  • environments.md · references/
  • integration.md · references/
  • native-5.md · references/
  • policies.md · references/
  • training.md · references/
  • vectorization.md · references/
  • __init__.py · scripts/
  • _common.py · scripts/
  • benchmark_vectorization.py · scripts/
  • env_contract_validator.py · scripts/
  • env_template.py · scripts/
  • inspect_checkpoint.py · scripts/
  • repro_plan.py · scripts/
  • train_template.py · scripts/
  • validate_plan.py · scripts/

SKILL.md (first lines)

# PufferLib

Choose the version before choosing an API. Reviewed **2026-10-01**:

| Profile | Status | Main use |
|---|---|---|
| Native source `5.0` | Current default branch and live documentation | C/CUDA environments, native trainer; CPU evaluation only |
| `pufferlib==3.0.0` | Latest PyPI release, published 2025-06-23; sdist only | Python/Gymnasium/PettingZoo adaptation and Torch PuffeRL |
| Pinned source `4.0` | Historical snapshot | C Ocean interface with an optional Torch fallback |

For **5.0**, read [references/native-5.md](references/native-5.md). The reviewed
revision is `6ffa5b10dbbbe4d1e8288367c7d9d3acd3bad4a2`. Its CLI is
`./puffer train` after building an environment, not `puffer train ENV_NAME`.
There is no 5.0 Python emulation/vector API or `--slowly` fallback.

The bundled plan schema deliberately supports only 3.0 and pinned 4.0; it does
not launch training. All native/PufferLib training examples are **source-reviewed,
illustrative, and not executed in this review**. Bundled synthetic checks are
executed CPU tests, not evidence of PufferLib installation or learning quality.
The PyPI sdist was hash-verified and its Python sources inspected; the moving
`3.0` branch differs, including its `load_policy` and logger contracts.

## Safe defaults

1. Start with bundled synthetic, CPU-only, network-free tools.
2. Do not import an arbitrary environment by dotted path. Bundled tools accept
   only allowlisted built-ins and slug identifiers.
3. Do not install or execute an unreviewed environment package, native
   extension, ROM, map, checkpoint, or pickle file.
4. Verify official source, immutable revision, licenses, checksums or
   attestations, and build hooks. Sandbox native builds and first execution.
5. Cap steps, environments, agents, workers, threads, buffers, memory, disk,
   render size, and wall time.
6. Keep training and evaluation environments/seeds separate.
7. Default logging to local/none. External logging requires explicit opt-in,
   disclosure acknowledgment, and separate artifact-upload approval.
8. Never pass W&B or Neptune credentials via CLI, INI, JSON, tags, run names, or
   logger configuration. Never print them.
9. Never dump all environment variables or recursively search for `.env`.
10. Hash checkpoint bytes before trusted, sandboxed loading; metadata inspection
    is not proof of safety.

## First local checks

All bundled CLIs are dependency-free and emit strict JSON:

```bash
python3 scripts/env_template.py --help
python3 scripts/env_contract_validator.py
python3 scripts/benchmark_vectorization.py --backend serial
python3 scripts/train_template.py
python3 scripts/validate_plan.py
python3 scripts/repro_plan.py
```

Defaults are synthetic, deterministic, bounded, local, CPU-only, no-network,
and dry-run where training would otherwise occur.

## Installation and provenance

### Published 3.0.0

PyPI supplies only `pufferlib-3.0.0.tar.gz`:

```text
sha256: 7df3a3e3f5f894d78d2a1f5374097890aec01473183e748abefe4f3faa10eaa9
Requires-Python: >=3.9
```

After source/build review, create a pinned uv project:

```bash
uv venv --python 3.11
uv add --exact --no-sync "pufferlib==3.0.0"
uv lock
uv sync --frozen
```

These installation commands are illustrative and were not executed.
Commit `pyproject.toml` and `uv.lock`; verify the archive digest and every
resolved dependency. The source build can compile native code and fetch build
assets, so resolve/build in a sandbox without credentials or sensitive mounts.
The archive declares NumPy `<2`, Gymnasium `<=0.29.1`, and PettingZoo `<=1.24.1`;
latest Gymnasium/NumPy are not valid substitutes for this profile. Its setup
supports Linux/macOS and rejects other systems. Python classifiers alone do
not establish a successful native build. The uploaded metadata does not pin Torch or CUDA; do not claim a supported CUDA
matrix that PyPI does not declare.

### Pinned 4.0 source

The reviewed branch head on 2026-07-23 was:

```text
25647630e1b15330bb3153a5a0d3ff8d234c3acf
```

Pin the commit, not branch `4.0`:

```bash
uv add --no-sync \
  "pufferlib @ git+https://github.com/PufferAI/PufferLib.git@25647630e1b15330bb3153a5a0d3ff8d234c3acf"
uv lock
```

The reviewed 4.0 package declares Python `>=3.10` and Torch `>=2.9`. The reviewed
PufferTank snapshot uses Ubuntu 24.04, Python 3.12, and an NVIDIA CUDA
13.0.2/cuDNN development image with the `cu130` Torch index, but does not pin
the exact Torch wheel or all system packages. Treat it as a reference, not a
complete lock. Never execute a remote installer directly from a pipe.

Read `references/training.md` before any installation or build.

## Environment workflow

### 1. Validate the contract

Gymnasium reset returns `(observation, info)`. Step returns:

```python

From K-Dense-AI/scientific-agent-skills, MIT.

More from K-Dense-AI/scientific-agent-skills

Signals

Stars
54,411
Forks
4,797
Open issues
8
Last commit (this folder)
Oct 1, 2026 (1 month ago)
Last release
Oct 1, 2026 (1 month ago)

From GitHub (fetched Oct 24, 2026).

Details

Version
1.4
License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

More from K-Dense-AI

Done for you

Rather not set it up yourself?

Chalk Labs scopes, builds and runs agents for your team: the task audit, the eval harness, the integrations and the weekly ops report. Fixed scope, priced before we start.

See how we build AI agents →Read the case studies

Chalk Labs is a two-founder AI and growth studio. We build AI agents, CRMs and MVPs for Web3 and AI companies, and have shipped 50+ product and token launches.

launches shipped
50+
launches shipped
media placements
500+
media placements
founders on every account
2
founders on every account

Press we've placed: Forbes · CoinDesk · Decrypt · Cointelegraph · The Block

Rahil Jain, Co-founder, Chalk Labs. Ex-Goldman Sachs engineer. You talk to the person who builds it.

Get pufferlib running in your business

Tell us what you want to automate. A founder replies within one working day with a plan, not a pitch deck.

Goes to the Chalk Labs founders, not the newsletter. Privacy

Need help deploying pufferlib?

CallGet help
Cite this page

pufferlib skill. Agent Mart. https://agentmart.dev/skills/k-dense-ai-pufferlib (last updated 2026-10-24)