Borrowing it
Nothing to install: this file belongs to tatemz/habitica-mcp. 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/tatemz/habitica-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/tatemz/habitica-mcpWrote 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/tatemz/habitica-mcp/agents-md)<a href="https://agentmods.dev/instructions/tatemz/habitica-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/tatemz/habitica-mcp/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/tatemz/habitica-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/tatemz/habitica-mcp/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 | $0.01612 | $0.01612 |
| Opus 5 | $0.00806 | $0.00806 |
| Sonnet 5 | $0.00322 | $0.00322 |
| Haiku 4.5 | $0.00161 | $0.00161 |
Grade A, and why
habitica-mcp 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 9d 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 — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
This is the operating manual for contributors and agents. Start with README.md
for setup and commands.
Product Pitch
habitica-mcp is a local-first MCP server for Habitica. Its job is to expose
small, audited Habitica capabilities to AI clients without hiding account
mutation behind vague natural-language magic.
Operating Principles
- Prefer deletion over accommodation. This repo is pre-release; replace weak paths rather than preserving compatibility with unshipped work.
- Determinism beats cleverness. Every tool should have a stable schema, stable response shape, and boring failure behavior.
- One behavior change, one check. Non-trivial logic needs the smallest runnable test or self-check that would fail if the logic regresses.
- Do not introduce abstractions until duplication proves the boundary exists.
- Never log Habitica API tokens, user tokens, request auth headers, or full profile payloads.
Codebase Style
Use pnpm. Do not migrate to bun unless the runtime actually changes away from Node stdio and the lockfile/tooling story gets simpler, not merely different.
Use Effect v4 beta interfaces. Keep Effect package versions aligned exactly.
Prefer generators and pipe() chains when they clarify sequencing; do not wrap
plain synchronous logic in Effect just to look functional.
MCP stdout is protocol-owned. Logs go to stderr only.
Effect v4 Beta
- Use Effect v4 beta APIs only. Keep
effectand every@effect/*package on the same4.0.0-beta.xversion. - Import schema from
effectunless local docs prove a narrower import is required. - Prefer
Effect.genorpipe()when sequencing is meaningful. - Keep pure synchronous calculations pure; do not wrap everything in
Effect.succeed. - Use Layers at runtime boundaries: MCP server, platform services, HTTP clients.
- Do not call schema constructors at module scope for data that can fail validation.
- Avoid compatibility shims for pre-release code. Replace the old path.
- If an Effect v3 habit conflicts with v4 docs, trust the v4 docs and leave a focused test.
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.
- 9d ago First seen · 153 lines · 1,612 tokens per session scan A 3a5d3d2758f2
habitica-mcp AGENTS.md is an instructions file published in the GitHub repository tatemz/habitica-mcp (0 stars, last pushed 1mo ago), licensed MIT. It adds 1,612 tokens to every session, about $0.0081 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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