Harness Iteration Framework

Harness Iteration Framework is an instructions file for GitHub Copilot from raydeStar/sir-thaddeus. It costs 1,634 tokens per session, scanned A, original, Apache-2.0.

A workflow for running and improving the Sir Thaddeus end-to-end test harness, a system that exercises the product and measures its behavior. It guides broad checks, focused debugging, and final validation.

In plain words
What is it for?
Use it to run full, suite-level, or single-test checks, narrow down failures, fix routing or state issues, and rerun targeted validation.
Why use it?
It helps separate real product problems from test-specific work and shortens the feedback loop while investigating failures.

Instructions file for GitHub Copilot

Written for GitHub Copilot: a Copilot chat mode or prompt.

Not installable on its own: it runs a file from its repository that does not travel with it. Clone the repository, or install whatever ships that file. The line is ./dev/harness.ps1 --all --judge none.

Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

Made for: GitHub Copilot.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for Harness Iteration Framework

README.md
[![agentmods](https://agentmods.dev/badge/instructions/raydestar/sir-thaddeus/harness-iteration-framework.svg)](https://agentmods.dev/instructions/raydestar/sir-thaddeus/harness-iteration-framework)
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<a href="https://agentmods.dev/instructions/raydestar/sir-thaddeus/harness-iteration-framework"><img src="https://agentmods.dev/badge/instructions/raydestar/sir-thaddeus/harness-iteration-framework.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,634 This file is loaded in full into every session.
When invoked 1,634 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.01634 $0.01634
Opus 5 $0.00817 $0.00817
Sonnet 5 $0.00327 $0.00327
Haiku 4.5 $0.00163 $0.00163

Measured 6d ago against content hash cb8a95d414f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

Harness Iteration Framework scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.github/instructions/harness-iteration-framework.instructions.md · 192 lines

How it starts

The opening of the file, as written. The whole thing — 192 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Harness Iteration Framework

Use this workflow when the goal is to improve real product behavior through the Sir Thaddeus harness. Optimize for fast diagnosis, disciplined reruns, and general fixes.

Core Rule

Treat the harness as a measuring device, not the thing to optimize directly. Improve routing, tool use, synthesis, fallback behavior, state handling, or runtime transport in product code. Do not tailor behavior to known tests.

Phase 0: Pick The Fastest Useful Loop

Choose the narrowest loop that still gives trustworthy signal.

  • Full baseline: ./dev/harness.ps1 --all --judge none
  • Suite baseline: ./dev/harness.ps1 --suite <name> --judge none
  • Single failing test: ./dev/harness.ps1 --suite <name> --test <id> --judge none
  • Judge validation after product fixes: ./dev/harness.ps1 --suite <name> --judge model

Rules:

  • Start broad only when establishing current system state or confirming final regression coverage.
  • After the first failing full run, narrow immediately to the failing suite or test.
  • Do not keep rerunning the full harness while debugging one issue unless the failure suggests cross-suite state leakage or broad routing regressions.

Phase 1: Run The Full Baseline

When asked for the full harness state, run:

./dev/harness.ps1 --all --judge none

Capture:

  • overall pass/fail summary
  • failing suites/tests
  • run id / artifact root

Do not conclude from the summary alone. The harness can under-report answer-quality defects when --judge none is used.

Phase 2: Break Failures Into Layers Before Editing

For each failing test, inspect artifacts in this order:

  1. score.json
  2. final.txt
  3. steps.jsonl
  4. input.json

Decide which layer failed:

  • No tools called when tools were needed: routing / intent classification / policy
  • Wrong tools called: tool selection / route shaping
  • Right tools called but wrong answer: synthesis / grounding / fallback logic
  • Tool results missing or malformed: tool adapter / runtime transport / parsing
  • Good answer but bad score: read the response and trace anyway; confirm whether this is a real product defect or a scoring blind spot

Read the full file on GitHub · 192 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 192 lines · 1,634 tokens per session scan A cb8a95d414f0

Subscribe to this mod's changes

Harness Iteration Framework is an instructions file published in the GitHub repository raydeStar/sir-thaddeus (13 stars, last pushed 5d ago), licensed Apache-2.0. It adds 1,634 tokens to every session, about $0.0082 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.