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.
npx agentmods add instructions/tommyengstrom/domaindriven/claude-mdgit clone --depth 1 https://github.com/tommyengstrom/domaindrivenWrote 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/instructions/tommyengstrom/domaindriven/claude-md)<a href="https://agentmods.dev/instructions/tommyengstrom/domaindriven/claude-md"><img src="https://agentmods.dev/badge/instructions/tommyengstrom/domaindriven/claude-md.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 | $0.00458 | $0.00458 |
| Opus 5 | $0.00229 | $0.00229 |
| Sonnet 5 | $0.00092 | $0.00092 |
| Haiku 4.5 | $0.00046 | $0.00046 |
Grade A, and why
domaindriven CLAUDE.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.
What it actually says
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Build Commands
- Build all packages:
cabal build all - Build specific package:
cabal build domaindriven - Run tests:
cabal test all - Run specific test:
cabal test domaindriven - Clean build:
cabal clean
Architecture Overview
DomainDriven is a synchronous event sourcing and CQRS library split into multiple packages:
Core Components
-
domaindriven-core: Core persistence model with PostgreSQL and in-memory backends
ReadModel/WriteModeltype classes define the persistence interfaceForgetfulInMemory: In-memory backend for testing/developmentPostgres: Production persistence with transactional guarantees- Synchronous event sourcing with locks to avoid eventual consistency issues
-
domaindriven: Effectful-based API layer
- Uses standard Servant combinators instead of custom ones
- Two main effects:
Aggregate(commands) andProjection(queries) - Dynamic dispatch interpreters for different backends
- Located in
domaindriven/
Key Design Patterns
-
Event Sourcing Model:
- Model = current state (derived from events)
- Events = immutable history of changes
applyEvent :: Model -> Stored Event -> Model
-
Command/Query Separation:
- Commands emit events and may update state
- Queries are read-only operations
- Both can be composed hierarchically
-
Index Types:
NoIndexfor single aggregates- Custom index types for multiple aggregates
- Functional dependencies can reduce type parameters
Development Notes
- All packages use extensive language extensions (see .cabal files)
- Strict warning settings (
-Wall -Werror) - fix all warnings before committing - The Effectful layer aims to simplify the API while maintaining type safety
- Tests use
hspecframework with in-memory backends
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.
- 2d ago First seen · 53 lines · 458 tokens per session scan A 3d01df28dde5
domaindriven CLAUDE.md is an instructions file published in the GitHub repository tommyengstrom/domaindriven (16 stars, last pushed 4d ago), licensed BSD-3-Clause. It adds 458 tokens to every session, about $0.0023 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 2026-09-01.
Other instructions, from other repositories
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Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.