Borrowing it
Nothing to install: this file belongs to leehack/mcp_dart. 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/leehack/mcp_dart/main/AGENTS.mdgit clone --depth 1 https://github.com/leehack/mcp_dartWrote 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/leehack/mcp_dart/agents-md)<a href="https://agentmods.dev/instructions/leehack/mcp_dart/agents-md"><img src="https://agentmods.dev/badge/instructions/leehack/mcp_dart/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/leehack/mcp_dart/agents-md"><img src="https://agentmods.dev/badge/instructions/leehack/mcp_dart/agents-md.svg" alt="Reviewed on agentmods" width="80" 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 | $0.01244 | $0.01244 |
| Opus 5.5 | $0.00498 | $0.00498 |
| Sonnet 5.5 | $0.00249 | $0.00249 |
| Haiku 4.5 | $0.00124 | $0.00124 |
Grade A, and why
mcp_dart 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.
mcp_dart Agent Guidelines
Use this file for durable, repository-specific rules. Keep detailed procedures in focused docs and runbooks.
Priorities
- MCP and JSON-RPC specification correctness.
- Backward compatibility and cross-SDK interoperability.
- Simple, maintainable code.
- Evidence-backed delivery: tests, examples, CI, and clean review threads.
Repository shape
- SDK:
lib/, public barrellib/mcp_dart.dart, minimum Dart 3.4. - CLI:
packages/mcp_dart_cli/, minimum Dart 3.12. - Tests:
test/and package-localtest/directories. - Release automation:
.github/workflows/andtool/release/. - Release process details:
tool/release/README.mdanddoc/mcp-2026-07-28-release-runbook.md.
Engineering principles
- KISS: Prefer the smallest clear design that preserves protocol behavior. Avoid speculative features, hidden normalization, and clever control flow.
- SOLID: Keep types and modules cohesive, make dependencies and capability boundaries explicit, and extend behavior without destabilizing existing APIs.
- DRY: Keep protocol constants, version parsing, schemas, and release rules in one source of truth. Reuse shared behavior when copies must stay identical; do not introduce an abstraction merely to remove a few obvious lines.
- Minimize direct and transitive dependencies. Do not add a dependency or raise a package's minimum Dart version without explicit human approval. Before requesting approval, document the need, alternatives, compatibility impact, and transitive footprint.
- Optimize measured or structurally clear hot paths. Do not trade correctness or readability for unproven micro-optimizations.
- Preserve public API compatibility unless a breaking change is explicitly approved and documented with migration guidance.
Protocol quality bar
- Treat the official MCP specification as authoritative. Convenience APIs must not distort wire-level JSON-RPC/MCP semantics.
- Preserve request IDs, metadata, method names, capability flags, error codes, and transport-specific behavior unless the specification permits otherwise.
- Distinguish advertised capabilities from runtime support and validate both.
- Keep lower-level protocol behavior observable and testable when adding ergonomic helpers.
- When a spec version is new or ambiguous, encode the compatibility decision in regression tests and cite the spec or rationale in focused documentation.
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.
- 1mo ago Changed · +3 lines · +48 tokens per session 4bae58f7e8fc
- 2mo ago First seen · 116 lines · 1,196 tokens per session scan A 04c30ef6e5e6
mcp_dart AGENTS.md is an instructions file published in the GitHub repository leehack/mcp_dart (116 stars, last pushed 3d ago), licensed MIT. It adds 1,244 tokens to every session, about $0.0050 per session on Opus 5.5. 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 2026-08-30.
Other instructions, from other repositories
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next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
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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 copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.