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astral-mcp: Instructions file for Codex

AGENTS.md

astral-mcp AGENTS.md is an instructions file for Codex, OpenCode from davidmosiah/astral-mcp. It costs 433 tokens per session, scanned A, original, MIT.

Repository instructions for developing astral-mcp, a local server that calculates astrology data such as birth charts, planetary movements, relationship comparisons, and moon phases for AI agents.

In plain words
What is it for?
Use it when modifying, testing, or building astral-mcp. It is especially relevant when working on its calculation engine, input and output descriptions, tools, or server entry points.
Why use it?
It gives coding agents the project layout, commands, and rules needed to change the code safely without adding storage, authentication, or unwanted network access.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is davidmosiah/astral-mcp's own configuration. It tells Codex and OpenCode how to work on astral-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything astral-mcp configures →

not rated 0repo yesterday A scan 433 tokens original MIT
View source ↗ davidmosiah/astral-mcp astral.delx.ai
Reuse

Borrowing it

Nothing to install: this file belongs to davidmosiah/astral-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.

Copy the file
curl -O https://raw.githubusercontent.com/davidmosiah/astral-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/davidmosiah/astral-mcp

Made for: Codex, OpenCode.

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.

agentmods badge for astral-mcp AGENTS.md

README.md
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Your own site
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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.

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Per session 433 This file is loaded in full into every session.
When invoked 433 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00433 $0.00433
Opus 5.5 $0.00173 $0.00173
Sonnet 5.5 $0.00087 $0.00087
Haiku 4.5 $0.00043 $0.00043

Measured 2mo ago against content hash e4902e609880, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

astral-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 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.

AGENTS.md · 42 lines

What it actually says

Agent Development Notes

Scope

This repo is astral-mcp — a local-first, precision-audited MCP server that computes natal charts, transits, synastry and moon phases for AI agents. It is stateless: no auth, no accounts, no persistence. The astrology engine is ported from the Alkhemia app and kept framework-free.

Layout

  • src/engine/ — pure computation, ported verbatim from Alkhemia (no MCP, no network except geocoding.ts). Treat as a vendored core; keep it portable.
  • src/schemas/common.ts — zod input/output schemas. Input descriptions are the agent-facing contract; write them for an LLM.
  • src/services/ — formatting + the agent-first metadata surfaces.
  • src/tools/astral-tools.ts — tool registration.
  • src/server.ts / src/index.ts — server factory and stdio/http entry.
  • scripts/ — node test scripts (smoke, accuracy, metadata).

Commands

  • Install: npm ci
  • Typecheck: npm run typecheck
  • Build: npm run build
  • Accuracy gate: npm run test:accuracy
  • Full gate: npm test

Rules

  • Keep every tool read-only and stateless. No tokens, no disk writes, no birth data persistence.
  • A natal chart must stay precision-audited by default. Don't regress the dual-engine cross-check — it's the project's reason to exist.
  • When adding an output field, also add it to the matching output schema: registerTool rebuilds z.object(shape) and validates structuredContent strictly, so any undeclared top-level key fails at runtime.
  • Tool descriptions are written for agents: say when to call the tool, what to pass, and what comes back.
  • The engine in src/engine/ mirrors Alkhemia. Fix bugs upstream too when they apply to both.
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.

  1. 2mo ago First seen · 42 lines · 433 tokens per session scan A e4902e609880

Subscribe to this mod's changes

astral-mcp AGENTS.md is an instructions file published in the GitHub repository davidmosiah/astral-mcp (0 stars, last pushed yesterday), licensed MIT. It adds 433 tokens to every session, about $0.0017 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.

ai-agentsastrologybirth-chartclaudeephemerishoroscope
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astral-mcp AGENTS.md next to 6 instructions from other repositories
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