Work
03AI tooling

Harness

A harness that lets engineering teams run, orchestrate, and supervise AI agents against their codebase and workflows.

Role  Solo build· Timeline  2025 — Present· Stack  SvelteKit · Hono · Vercel AI SDK · TypeScript
Harness — agent orchestration dashboard
Harness — agent orchestration dashboard

Context

Harness began from a simple frustration: AI coding agents are powerful, but hard to trust at scale. Teams need a way to run agents against a real codebase, watch exactly what they’re doing, and step in when it matters — not a black box that either works or silently doesn’t.

What I built

  • An orchestration layer that runs and supervises multiple AI agents against a team’s codebase and workflows.
  • Real-time streaming of agent reasoning, tool calls, and diffs — built on the Vercel AI SDK with a Hono API and a SvelteKit front-end.
  • A tool & permission system so agents act within explicit boundaries, with human approval gates on sensitive operations.
Live agent run — streamed reasoning & tool calls
Live agent run — streamed reasoning & tool calls
Human-in-the-loop approval gates
Human-in-the-loop approval gates

Highlights

  • End-to-end streaming architecture: SvelteKit ↔ Hono ↔ model providers, with resumable sessions and clean backpressure.
  • Designed developer-experience first — every agent action is visible, inspectable, and reversible.
Fig. 1 — SvelteKit ↔ Hono ↔ agents / tools architecture
Fig. 1 — SvelteKit ↔ Hono ↔ agents / tools architecture

Outcome

An end-to-end prototype — agents run against a real codebase with streaming visibility, a tool-and-permission system, and human approval gates on sensitive actions.

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