devkit AGENTS.md

Repository instructions for Devkit that define how coding work should be explored, built, tested, and refined. They explain that TDD, or writing tests before code, is optional rather than a rule for every change.

In plain words
What is it for?
Use them to plan feature work, decide which tests are worthwhile, avoid turning temporary experiments into permanent tests, and run broader regression checks before delivery.
Why use it?
They help agents choose checks based on the user’s goal and real risks instead of treating a passing test suite as proof that the work is correct.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/zhpeng24/devkit/agents-md
Clone the repo
git clone --depth 1 https://github.com/zhpeng24/devkit

Made for: Codex, OpenCode.

Per session 362 This file is loaded in full into every session.
When invoked 362 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 $0.00362 $0.00362
Opus 5 $0.00181 $0.00181
Sonnet 5 $0.00072 $0.00072
Haiku 4.5 $0.00036 $0.00036

Measured yesterday against content hash 6db45027b140, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

devkit AGENTS.md 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 yesterday.

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.

AGENTS.md · 32 lines

What it actually says

Devkit

Development constitution

  • SIES is the default engineering sequence: Goal → Explore → Prototype → Evaluate → Refine → Engineer → Regress → Learn.
  • Scale or merge SIES phases for small deterministic work; do not replace the sequence with a different ceremony for each complexity level.
  • Measure progress by goal alignment and closed uncertainty, not by test count, coverage theater, review count, or completed workflow steps.
  • Testing is evidence for user goals, stable contracts, and real risks. TDD is an optional Engineering strategy, not the default lifecycle for every code change.
  • A passing test suite does not prove success when the Goal Contract or user scenario is unmet.
  • Every persistent test must protect an observable success signal, stable contract, or real failure mode and fail when that behavior breaks.
  • During Explore and Prototype, run only checks that answer the current decision. Do not prematurely turn disposable probes into regression tests.
  • Finish a coherent feature or repair batch before target regression; run the broader project regression once before delivery.
  • Do not rerun an unchanged suite when relevant code, configuration, dependencies, fixtures, environment, and evidence have not changed.
  • Move tests earlier for justified risk such as bug reproduction, security, migration, concurrency, public API compatibility, or cross-platform behavior.
  • GitHub stores goals, evidence, decisions, and delivery links; it is not a fixed linear workflow engine.
  • Batch documentation, skill, and metadata edits before validation. Do not start a full regression or independent review for every edited file.
  • Promote a process learning only when repeated evidence, a high-impact event, a substantially better method, or explicit user direction justifies it.
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. yesterday First seen · 32 lines · 362 tokens per session scan A 6db45027b140

Subscribe to this mod's changes

devkit AGENTS.md is an instructions file published in the GitHub repository zhpeng24/devkit (2 stars, last pushed 1mo ago), licensed MIT. It adds 362 tokens to every session, about $0.0018 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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