---
title: "tiny-harness-builtin"
description: "tiny-harness's opinionated defaults: the system prompt, the intrinsic tools and the default hook bodies. Loaded first; every registration is overridable by a later plugin."
canonical: https://agentpluginsdirectory.com/plugins/tiny-harness-builtin
last-updated: 2026-10-12
---

# tiny-harness-builtin
tiny-harness's opinionated defaults: the system prompt, the intrinsic tools and the default hook bodies. Loaded first; every registration is overridable by a later plugin.
- Slug: tiny-harness-builtin
- Publisher: MadaraUchiha-314
- Repository: https://github.com/MadaraUchiha-314/tiny-harness
- Manifest: tiny_harness/builtin/plugin.json
- Version: 0.1.0
- License: Apache-2.0
- Category (editorial): other
- Skills: 0
- MCP servers: 0
- Stars: 0
- Repository created: 2026-10-08
- Repository last pushed: 2026-10-12
- Publisher type: User
- Listing: https://agentpluginsdirectory.com/plugins/tiny-harness-builtin
- Schema: https://agent-plugins.org/schemas/1.0.0/plugin.schema.json

## What tiny-harness-builtin does, in the publisher's words

An opinionated, production-grade agent harness for customer-facing agentic workflows: A2A 1.0 in and out, MCP tools, Agent Skills and Agent Plugins, one Temporal workflow per task, hooks around every operation, and a TUI and a web renderer. It is being built in the stacked pull requests of issue #3; the spec chain lives under docs/specs/issue-3/.

- An A2A 1.0 server (JSON-RPC and REST, streaming, push notifications) and an A2A client for remote agents; three extensions (task, channel, A2UI 0.9.1).
- A core loop of hooks around every operation: ingest, assemble, compact, call the model, run tools, decide completion. Intrinsic tools cover plans, sub-tasks, help requests, participants, skills and UI.
- Temporal owns the whole request lifecycle: one workflow per task, every model and tool call an activity, workflow-managed retries, a durable event log, continue-as-new.

From the project README, punctuation lightly normalized. Full text: https://raw.githubusercontent.com/MadaraUchiha-314/tiny-harness/HEAD/README.md