Ness Agent — hackable coding-agent harness

Ness Agent

CI Python License

Ness Agent is an experimental, hackable coding-agent harness for engineers who want to own the loop. It ships as a Python SDK you can embed in your own tools and Ness, an interactive CLI for day-to-day coding sessions.

0.x experimental — APIs may change until 1.0. See CHANGELOG.

Table of contents

Overview

Component What it is
Ness Agent SDK LangGraph agent loop, built-in tools, permissions, memory, skills, hooks, MCP, compaction, reflection, tracing
Ness CLI Terminal UI (ness), plan/act modes, git worktrees, global config, .ness/ project layout

Both are included in the ness-agent PyPI package. OpenRouter-compatible chat models, native tool-calling, and filesystem-driven extension points under .ness/.

Installation

Requires Python 3.12+.

pip install ness-agent

Optional tracing support:

pip install ness-agent[tracing]

From source:

Contributors (run tests, use project venv):

git clone https://github.com/Sagnnik/ness-agent.git
cd ness-agent
uv sync
uv run ness

Install ness on your PATH from a local clone (editable):

git clone https://github.com/Sagnnik/ness-agent.git
cd ness-agent
uv tool install -e .
ness

Or with pip: pip install -e . (then run ness from that environment).

Quick start — CLI (Ness)

export OPENAI_API_KEY=...   # or set via /config on first launch
ness
/init                       # create .ness/ and global config

Headless one-shot:

ness -p "what does the auth module do?"

Parallel isolated session:

ness --worktree feature-x

Full CLI reference: docs/cli.md · Configuration: docs/configuration.md

Quick start — SDK

import asyncio
from langchain_core.tools import tool
from ness_agent import NessAgent, PromptLayers, PromptLayersConfig

@tool
def ping() -> str:
    """Return pong."""
    return "pong"

async def main() -> None:
    agent = NessAgent(
        model=your_chat_model,
        tools=[ping],
        prompt=PromptLayers(PromptLayersConfig(l0="You are a helpful agent.", persona="Be concise.")),
    )
    session = agent.session(thread_id="demo-1")
    result = await session.run("say hello")
    print(result.text)

asyncio.run(main())

Full SDK guide: docs/sdk.md · Architecture: docs/architecture.md

Documentation

Guide Description
docs/README.md Documentation index
docs/sdk.md SDK usage, public API, tracing
docs/cli.md Ness TUI, slash commands, MCP, permissions
docs/configuration.md Global config, .ness/ layout, env vars
docs/architecture.md Prompt layers, modes, memory, compaction

Contributing

Contributions welcome. See CONTRIBUTING.md for dev setup and PR guidelines.

License

Licensed under the Apache License 2.0. See LICENSE.

Project links

Data verified by PyPI on Jul 31, 2026
Data provided by the project maintainers, verified at the time the release was uploaded to PyPI.

Key dates

PyPI data
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  • Released:
Newer release available (0.2.2)

1 maintainer

PyPI data
Data sourced directly from PyPI's database.
Avatar for sagnnikb from gravatar.com sagnnikb

Credits

Author: Sagnnik Biswas

GitHub Statistics

Data verified by PyPI on Jul 31, 2026
The GitHub source repository was provided by the project maintainers and verified by PyPI at the time of upload. Stars, forks, and open issues/PRs are derived from that repository and have not been independently verified.

License expression

Apache-2.0
View SPDX License List

Requires

Python >=3.12

Provides Extra

tracing

Tags

agent cli coding-agent langgraph llm mcp

Classifiers

Report project as malware

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