LiteHarness · open source · MIT

One harness for every coding CLI.

Portable cross-CLI agent orchestration. Spawn, name, message, and programmatically control agent sessions from pure Python. Claude Code, Codex, Copilot, Pi, Kilo, OpenCode — one harness, one inbox.

Install

pip install liteharness

0 CLIs

Supported agents

0 tiers

Agent hierarchy

Polymathic thinkers

0 deps

Beyond psutil

GitHub →PyPI Claude Code Plugin

What the harness gives you

Multi-CLI orchestration

Spawn and coordinate agents across Claude Code, Codex, Codex Desktop, Copilot, Pi, Kilo, OpenCode — one harness, one inbox, every CLI.

Inter-agent messaging

Maildir-style shared inbox at ~/.liteharness/inbox/. Atomic file rename is the mutex. Presence files do discovery. Same pattern Maildir used in 1995.

ConPTY daemon

Headless agent control via Windows ConPTY (pywinpty). Bearer-token TCP daemon on port 7450. Spawn invisible background agents, send /compact, read output programmatically.

UIAutomation (headed mode)

Read and write to visible Windows Terminal panes via PowerShell UIAutomation. Clipboard paste for atomic input. Watch agents type into each other's terminals in real time.

Deterministic naming

Every agent gets a memorable two-word name derived from its UUID. SwiftRelay, IronWatch, PrimeFlint. Same UUID always produces the same name. Zero state, zero storage.

5-tier hierarchy

Orchestrator → leader → worker → thinker → reviewer. Emergent in practice, formalized in config. Each tier has its own MCP tool surface.

Quick start

Six commands cover ~90% of day-to-day orchestration.

```
pip install liteharness
```
Install the package
```
liteharness init
```
Initialize, detect CLIs, install hooks

liteharness spawn --pty --model sonnet --name Worker --prompt "fix the flaky test"

Spawn a headless worker agent

```
liteharness discover
```
List active agents in the fleet

liteharness send <agent-id> "try approach B" --from <your-id>

Send a direct message between agents

```
liteharness send-input <id> "/compact"
```
Inject a slash command into a running agent

Five tiers, one inbox

Emergent in practice, formalized in config. Each tier has its own MCP tool surface and permission scope.

Orchestrator

Coordinates the whole fleet

Leader

Domain specialist, owns a feature area

Worker

Executes atomic tasks

Thinker

Read-only polymathic analysis

Reviewer

Quality gate before merge

Convergence #7

Filesystem is the message bus.

LiteHarness shipped Maildir-style inter-agent messaging in January 2026. Five months later, Nico Bailon's pi-intercom arrived at the same architecture independently: peer messaging across CLI sessions, flat hierarchy, presence/discovery, emergent coordination. Eric Michaud demoed it in his May 2026 video "These AI Agents Talk to EACH OTHER Across Terminals." Two parties, same answer, five months apart.

The pattern is real. The harness is the answer.

Read the full story Star on GitHub

Hire the builder

Building agents? Let's talk.

LiteHarness is the open part. The full LiteSuite stack and the 28 years of shipped systems behind it aren't. Contract, fractional CTO, full-time, or co-founder — I'm open.

ryan@litesuite.dev Read the full story

Pair it with the plugin.

The Python package gives you the runtime. The Claude Code plugin gives you the orchestrator skills — 60 skills, 88 agents (49 polymathic thinkers like Feynman, Carmack, Shannon, Lovelace) ready to dispatch.

/plugin install liteharness

github.com/ahostbr/liteharness-plugin →