foldcase AGENTS.md

A project instruction file that sets the rules for working on Foldcase, including its tools, code structure, and test-first development requirements.

In plain words
What is it for?
Keeping changes consistent with the project’s fixed technology choices, runtime structure, documentation build, and TDD (writing tests before code) practices.
Why use it?
It gives humans and coding agents one shared set of project rules to follow.

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/tao-io/foldcase/agents-md
Clone the repo
git clone --depth 1 https://github.com/tao-io/foldcase

Made for: Codex, OpenCode.

Per session 2,329 This file is loaded in full into every session.
When invoked 2,329 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 $0.02329 $0.02329
Opus 5 $0.01164 $0.01164
Sonnet 5 $0.00466 $0.00466
Haiku 4.5 $0.00233 $0.00233

Measured 2d ago against content hash 6bed8e81ed3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

foldcase 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 2d 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.

AGENTS.md · 151 lines

How it starts

The opening of the file, as written. The whole thing — 151 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Working rules — Foldcase

Binding for humans and agents. Short on purpose. The reasoning lives in docs/adr/; this file is the rules that follow from it.

The stack is fixed

  • Bun is the development toolchain: the package manager, the test runner, and the version mise pins. Not npm, not pnpm, not turbo. Vite builds one thing and one thing only — the documentation site under docs/site/, by declared exception (ADR-0003).
  • Node and Bun both run the shipped tool. The core is runtime-agnostic Effect and each runtime gets one thin shell — src/main.ts (Node) and src/main.bun.ts (Bun). A shell binds a runtime, hands the program process.argv, and writes back the exit code; anything else in a shell is a bug. See ADR-0002 › Amendment 1.
  • The build is tsc -b, and there is no bundler. mise run build compiles src/ to dist/ — one .js and one .d.ts per source file — and copies the coverage collector beside its caller. bun build --compile is not used and is not coming back: a compiled binary resolves import(path) inside its own /$bunfs, so it could never load an external *.showcase.ts, which is the whole job.
  • Effect v4 for all non-trivial logic: typed errors, Layers, Schema for every contract. Not bare async/throw. Effect is a peer dependency — never promote it to a hard dependency, or a consumer ends up with two Effect instances. Both @effect/platform-* packages are optional peers: a consumer needs only the one their shell runs, and the library entry points need neither.
  • Foldkit is the only framework this line supports. No React, no Solid, no Vue, no Svelte — not in source, not in tests, not in devDependencies.
  • No CSF-3. No Meta, no StoryObj, no export default meta, no *.stories.ts. A catalog is export const showcases: ReadonlyArray<Showcase> in a *.showcase.ts file.
  • TypeScript only under src/. The single exception is src/coverage/collector.mjs, the Node V8 coverage instrument, which is allowlisted by name in the stack gate.
  • docs/site/ is the documentation site, a foldocs (Foldkit) application that Vite builds and mise run docs:build drives. It is the one place a bundler runs. Its pages are derived from README.md, CHANGELOG.md and docs/adr/ on every build and are gitignored, so the prose has exactly one home. Nothing there touches src/, dist/ or the tarball. See ADR-0003.

Read the full file on GitHub · 151 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. 2d ago First seen · 151 lines · 2,329 tokens per session scan A 6bed8e81ed3c

Subscribe to this mod's changes

foldcase AGENTS.md is an instructions file published in the GitHub repository tao-io/foldcase (1 stars, last pushed 28d ago), licensed MIT. It adds 2,329 tokens to every session, about $0.0116 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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