domain

An engineering guide for using a project's domain documentation while exploring its code. Domain documentation explains the project's business terms, concepts, and architectural decisions.

In plain words
What is it for?
Use it when exploring a repository, reading its CONTEXT.md and architecture decision records, naming domain concepts, or checking whether a proposed change conflicts with documented decisions.
Why use it?
It helps an agent use the project's own vocabulary and avoid contradicting recorded decisions. A glossary is a list of defined terms, while an ADR records why an architecture choice was made.

Agent

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 agents/a9a4k/tour/domain
Clone the repo
git clone --depth 1 https://github.com/a9a4k/tour
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 337 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 84% copy Near-identical to another mod 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 $0.00000 $0.00337
Opus 5 $0.00000 $0.00169
Sonnet 5 $0.00000 $0.00067
Haiku 4.5 $0.00000 $0.00034

Measured 2d ago against content hash bafcfc3f08df, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

domain 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.

Origin

This is a copy

84% identical to domain — 30 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

docs/agents/domain.md · 36 lines

What it actually says

Domain Docs

How the engineering skills should consume this repo's domain documentation when exploring the codebase.

This repo uses a single-context layout: one CONTEXT.md and one docs/adr/ at the repo root.

Before exploring, read these

  • CONTEXT.md at the repo root.
  • docs/adr/ — read ADRs that touch the area you're about to work in.

If any of these files don't exist, proceed silently. Don't flag their absence; don't suggest creating them upfront. The producer skill (/grill-with-docs) creates them lazily when terms or decisions actually get resolved.

File structure

/
├── CONTEXT.md
├── docs/adr/
│   ├── 0001-event-sourced-orders.md
│   └── 0002-postgres-for-write-model.md
└── src/

Use the glossary's vocabulary

When your output names a domain concept (in an issue title, a refactor proposal, a hypothesis, a test name), use the term as defined in CONTEXT.md. Don't drift to synonyms the glossary explicitly avoids.

If the concept you need isn't in the glossary yet, that's a signal — either you're inventing language the project doesn't use (reconsider) or there's a real gap (note it for /grill-with-docs).

Flag ADR conflicts

If your output contradicts an existing ADR, surface it explicitly rather than silently overriding:

Contradicts ADR-0007 (event-sourced orders) — but worth reopening because…

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 · 36 lines · 0 tokens per session scan A bafcfc3f08df

Subscribe to this mod's changes

domain is an agent published in the GitHub repository a9a4k/tour (5 stars, last pushed 2mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 337 tokens. A static security scan graded it A with 0 findings. It is 84% identical to domain, differing in 30 lines, and is treated as a copy.