01
harnext
The coding agent harness
Reads, writes, and edits code, runs shell, and drives MCP — on open-source, local, or any provider. The whole harness your team runs in the terminal.
❯
Open source · MIT licensed
Build the harness.
Engineer the context.
Two open-source tools that work as one — a terminal-native coding agent harness, and the context engine that feeds its brain.
02
◇ Context Engine
The brain of your agent
Every event across your org — Slack, HubSpot, Stripe, Jira — streams in. The engine ranks and prunes it into token-efficient context, wired straight into the harness.
Trusted by
Open source
Built in the open.
MIT licensed, end to end.
harnext and Context Engine are free and open source. Read the code, open an issue, or ship a change — the whole harness was built to be forked.
QualityUnit / harnext Star
The coding agent harness — tools, providers, sandbox, and a runner that ships work unattended.
QualityUnit / context-engine Star
Token-efficient context for any harness — continuous indexing, ranking, and caching over a small HTTP + MCP surface.
Book a callPrefer a walkthrough? We'll show you harnext + Context Engine on your stack.
01 — The harness · harnext
From a one-line task to a reviewed change.
On rails.
harnext ships the agent, the harness, and the runner — no glue scripts, no agent server. Point it at open-source or custom models to keep development in-house, and hand your team a harness that works out of the box: it reads, writes, and edits files, runs shell, drives MCP servers, then runs the whole loop as a staged pipeline you can hand off and walk away from.
❯ refactor packages/api/auth — split the session helper
read packages/api/auth/session.ts · 218 lines
grep "createSession" · 9 matches · 4 files
plan · 3 steps — extract tokens.ts, thin the helper, update imports
edit packages/api/auth/tokens.ts +47 −0
edit packages/api/auth/session.ts +8 −52
bash npm test -- auth ✓ 23 passing · 1.2s
↑ 3.1k ↓ 0.9k tokens · change ready for review
Interactive REPLA terminal agent that reads, writes, edits, runs bash, and drives MCP servers. One-shot mode with -p for scripts and automation.
Open & custom modelsAnthropic, OpenAI, Google, Ollama, NVIDIA + 20 more — or point --base-url at a local or self-hosted endpoint and keep everything in-house.
Drives any agentRun interactive yourself, or hand a stage to claude-code or codex with sandbox flags wired in.
Runs unattendedRegister a runner on your own hardware as a systemd / launchd service. Idempotent install; picks up where it left off.
Ollama
Anthropic
OpenAI
Google
NVIDIA+ 20 more02 — The context engine · context-engine
Every event in your org,
turned into token-efficient context.
Stripe events, Slack messages, GitHub activity, Jira and LiveAgent tickets, website data — everything that happens across your organization streams into the Context Engine. When an agent asks, it ranks, prunes, dedupes, and caches so every call carries only what matters. Drop it into harnext, Claude Code, Codex, or your own loop.
Events processed
4,796 events indexed · last 14 days
7d14d
14d ago7dtoday
Tokens / query
14.2k · −89%
Context builds
334
Sources · status
10 live
S#general▸ slack channel
412
events indexed
2h agolast sync
Live⚡ synced 2h ago
⎇qualityunit/urlslab▸ git repository
358
events indexed
2h agolast sync
Live⚡ synced 2h ago
◆#bug-report▸ discord channel
2,738
events indexed
2h agolast sync
Live⚡ synced 2h ago
−89%
fewer tokens per query, on average — without the agent losing the thread.
Measured against passing the raw working set. Your mileage varies with repo size and query.
Continuous indexSources stream events into the grid — no manual re-indexing. Whatever your agent queries is always current.
Relevance rankingScores and orders candidates per query, then prunes the long tail before it ever reaches the model.
Dedup & cacheCollapses repeats and caches hot context, so repeat calls don't re-pay for the same tokens.
Drop-in for any harnessA small HTTP + MCP surface. Point harnext, Claude Code, Codex, or your own loop at it.
Plugs into the harness you already use →harnextClaude CodeCodex
pi.dev
Claude CodeCodexpi.devQuick start
Three commands to a running agent.
01
Install
$ npm i -g harnext
Requires Node ≥ 20. Everything lives under ~/.harnext.
02
Wire it up
$ cd my-repo
$ harnext setup
✓ context engine connected · harness ready
Connects your sources and wires the harness into your repo.
03
Ship
$ harnext
❯ fix the flaky auth test
✓ change ready for review
Use it interactively, or let it run a queued task unattended.