Borrowing it
Nothing to install: this file belongs to narumiruna/yfinance-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/narumiruna/yfinance-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/narumiruna/yfinance-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/narumiruna/yfinance-mcp/agents-md)<a href="https://agentmods.dev/instructions/narumiruna/yfinance-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/narumiruna/yfinance-mcp/agents-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 5.1 | $0.00633 | $0.00633 |
| Opus 5 | $0.00316 | $0.00316 |
| Sonnet 5 | $0.00127 | $0.00127 |
| Haiku 4.5 | $0.00063 | $0.00063 |
Grade A, and why
yfinance-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 8d 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 — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Repository Guidelines
Project Structure & Module Organization
src/yfmcp/server.py: FastMCP server, tool registration, and async wrappers aroundyfinancecalls.src/yfmcp/chart.py: chart generation (price_volume,vwap,volume_profile) and WebP image encoding.src/yfmcp/types.py: shared Literal types (SearchType,TopType,Period,Interval,ChartType,ErrorCode).src/yfmcp/utils.py: JSON helpers, includingcreate_error_response().tests/: async pytest suite for server tools, charts, and type behavior.README.md: end-user setup and usage guide. Demo chatbot link points to the dedicatedyfinance-mcp-demorepository.
Architecture Overview
- MCP tools are exposed from
yfmcp.serverwithyfinance_-prefixed names:yfinance_get_ticker_info,yfinance_get_analyst_price_targets,yfinance_get_analyst_estimates,yfinance_get_upgrades_downgrades,yfinance_get_fund_data,yfinance_get_ticker_news,yfinance_search,yfinance_get_top,yfinance_screen,yfinance_get_price_history,yfinance_get_financials,yfinance_get_holders,yfinance_get_option_chain,yfinance_get_option_dates. - All blocking
yfinanceoperations MUST be wrapped withasyncio.to_thread(). - Errors MUST be returned via
create_error_response()with structured JSON (error,error_code, optionaldetails). - Chart responses are returned as base64-encoded WebP
ImageContent; tabular history uses Markdown tables.
Build, Test, and Development Commands
uv sync: install runtime dependencies.uv sync --extra dev: install development dependencies.uv run yfmcp: run the MCP server.uv run ruff check .anduv run ruff format .: lint/format.uv run ty check src tests: type check.uv run pytest -v -s --cov=src tests: full test run with coverage.
Coding Style & Testing Guidelines
- Python
>=3.12, line length120, one import per line (ruff isort). - Test files:
tests/test_*.py; test functions:test_*. - Use
pytest+pytest-asynciofor async behavior. - If
.pre-commit-config.yamlexists and code/config changed, runprek run -a(fallback:pre-commit run -a).
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.
- 8d ago First seen · 42 lines · 633 tokens per session scan A 269775c63d36
yfinance-mcp AGENTS.md is an instructions file published in the GitHub repository narumiruna/yfinance-mcp (190 stars, last pushed yesterday), licensed MIT. It adds 633 tokens to every session, about $0.0032 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 2026-08-30.
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