What is astronomy-oracle CLAUDE.md?

Project instructions for Astronomy Oracle, a server that provides astronomy catalogue data and calculates when and where objects can be observed. It documents the TypeScript and Node.js setup, project structure, commands, and tests.

Use it when changing astronomy data handling, observation calculations, server tools, formatting, or tests in Astronomy Oracle.

It gives a coding agent the project-specific information needed to work consistently in the repository. It also explains how to build, run, inspect, and test the server.

How gregario/astronomy-oracle configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to gregario/astronomy-oracle. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/gregario/astronomy-oracle/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/gregario/astronomy-oracle

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/gregario/astronomy-oracle/claude-md/github.svg)](https://agentmods.dev/instructions/gregario/astronomy-oracle/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/gregario/astronomy-oracle/claude-md"><img src="https://agentmods.dev/badge/instructions/gregario/astronomy-oracle/claude-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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/gregario/astronomy-oracle/claude-md"><img src="https://agentmods.dev/badge/instructions/gregario/astronomy-oracle/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 250 This file is loaded in full into every session.

When invoked 250 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found 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.

Model	Per session	Once invoked
Fable 5.1	$0.00250	$0.00250
Opus 5.5	$0.00100	$0.00100
Sonnet 5.5	$0.00050	$0.00050
Haiku 4.5	$0.00025	$0.00025

Measured 2mo ago against content hash 4b7cddceed20, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

astronomy-oracle 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 2mo 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.

CLAUDE.md · 29 lines

What it actually says

Astronomy Oracle

MCP server providing accurate astronomical catalog data and deterministic observing computations.

Stack

TypeScript + Node.js 18+
@modelcontextprotocol/sdk
Vitest for testing
Embedded OpenNGC data (CC-BY-SA 4.0)

Commands

npm test — run tests
npm run build — compile TypeScript
npm run dev — run with tsx
npm run inspect — open MCP Inspector

Architecture

src/data/ — CSV parsing, catalog store, coordinate parsing
src/astro/ — Deterministic astronomy math (Julian date, sidereal time, alt/az, rise/transit/set)
src/tools/ — MCP tool implementations (lookup-object, search-objects, plan-session)
src/lib/ — Shared utilities (fuzzy search)
src/format.ts — Markdown formatters
data/ — Bundled OpenNGC CSV files

Testing

Tests in tests/ mirroring src/ structure
Astronomy math tests validate against known reference values
Tool tests use in-memory MCP transport

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.

2mo ago First seen · 29 lines · 250 tokens per session scan A 4b7cddceed20

Subscribe to this mod's changes

astronomy-oracle CLAUDE.md is an instructions file published in the GitHub repository gregario/astronomy-oracle (3 stars, last pushed 12d ago), licensed MIT. It adds 250 tokens to every session, about $0.0010 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 2026-08-31.

Scientific

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astronomy-oracle: Instructions file for Claude Code