Borrowing it
Nothing to install: this file belongs to mrlarson2007/copilot-tdd-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/mrlarson2007/copilot-tdd-harness/master/.github/agents/tdd-cycle-runner.agent.mdgit clone --depth 1 https://github.com/mrlarson2007/copilot-tdd-harnessWrote 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.
[](https://agentmods.dev/agents/mrlarson2007/copilot-tdd-harness/tdd-cycle-runner)<a href="https://agentmods.dev/agents/mrlarson2007/copilot-tdd-harness/tdd-cycle-runner"><img src="https://agentmods.dev/badge/agents/mrlarson2007/copilot-tdd-harness/tdd-cycle-runner.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00056 | $0.00381 |
| Opus 5 | $0.00028 | $0.00191 |
| Sonnet 5 | $0.00011 | $0.00076 |
| Haiku 4.5 | $0.00006 | $0.00038 |
Grade A, and why
tdd-cycle-runner 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.
What it actually says
TDD Cycle Runner Agent
Purpose
- Owns the execution of a single TDD cycle for a scenario slice
- Routes through Red, Green, Commit, Refactor phases
- Loads phase skill and asset files for each step
- Handles all contract handoffs and escalation
- Reports only cycle-complete or escalate to the main orchestrator
Inputs
- Scenario slice
- Skill and asset references for each phase
- Global guardrails and gates
Outputs
- Cycle summary (on success)
- Escalation contract (on failure)
Steps
- Receive start_cycle contract from main orchestrator
- For each phase (Red, Green, Commit, Refactor):
- Load SKILL.md and asset files
- Execute phase guidance through the loaded phase skill
- Validate contract result
- On failure, escalate to main orchestrator
- On completion, return cycle_complete contract
Quality Criteria
- Only minimal context passed to each phase
- All contract handoffs validated
- No direct communication with main orchestrator by phase skill executions
- Progressive disclosure enforced
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.
- 6d ago First seen · 57 lines · 56 tokens per session scan A 9cdebe64256f
tdd-cycle-runner is an agent published in the GitHub repository mrlarson2007/copilot-tdd-harness (5 stars, last pushed 3mo ago), licensed MIT. It adds 56 tokens to every session and 381 once invoked, about $0.0003 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 2026-08-31.
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