v0.4 · pre-1.0 · MIT licensed ·

A minimal, opinionated agent harness.

Build agents without adopting a stack you don’t need. Focused scope, straightforward code, easy to fork.

install.sh
copy$ uv add thinharness
# or: pip install thinharness
# requires python 3.11+

resolved · 23 files · 7,985 LOC
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Opinions

the reason it stays small
purpose_built

Purpose-built agents

ThinHarness is for bounded agent loops inside software you control, not open-ended interactive assistants.

no_bash

No bash by default

Bash stays out of the default tools, with an opt-in BashTool only for prototyping before typed tools.

search

Search is a top priority

Ripgrep exposed as compact grouped results, tuned for documents and business workflows — plus a custom JSONL search tool for structured corpuses.

parallel_llm

Parallel LLM calls, built in

Fan out from inside the harness when a workflow needs efficient parallel processing or majority vote for reliability.

no_compaction

No compaction

Compaction makes sense for sprawling coding sessions. For business agents the fix is smarter task decomposition and context management

no_deployment

No deployment layer

Serving, auth, durable jobs, and session storage stay yours. ThinHarness owns the agent loop, not the production stack around it.

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Explore