# Caelus

**Canonical:** https://apis.io/providers/ephemengine-com/  
**Website:** https://www.ephemengine.com/  
**APIs profiled:** 2

Caelus is a clean‑room, MIT‑licensed TypeScript suite for validated astrology computation. It computes planetary positions, charts, events, hellenistic timing techniques, Vedic methods, and citable chart facts across browser, edge, Node, and MCP clients, without Swiss Ephemeris code, AGPL licensing, or ephemeris files. The project provides a rich API for developers to integrate precise astrological data into applications, with extensive documentation, a playground, and a growing set of MCP tools for AI clients.

## Kin Score — 20.0 / 100 (emerging)

Scored 2026-11-13 under rubric 0.28.0.

| Facet | Score |
|---|---|
| Discoverability | 56.7 |
| Contract Quality | 9.4 |
| Contract Governance | 22.0 |
| Operational Transparency | 0.0 |
| Developer Ergonomics | 42.9 |
| Access Clarity | 8.5 |

Regulatory layer — **Horizontal (data, software, accessibility, platform)**: 8.8 (matched via fallback).

## Agent readiness — 16.4 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | documented |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |
| Pagination Ratio | na |
| Operation Distinctiveness | na |
| MCP Tool Quality | na |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## APIs (2)

- **Caelus MCP** — MCP streaming HTTP endpoint providing access to ephemeris data and tools.
- **Caelus API** — Caelus API as documented publicly: 1 operations. Contract generated from the documentation by API Evangelist (2026-11-07); not the provider's own document.

## MCP servers (1)

- **Caelus MCP Server** — Remote MCP server at www.ephemengine.com.

## Security (1)

- **Caelus Domain Security** — TLSv1.3 · HSTS · DMARC

## Tags

Astrology, TypeScript, Open Source, MIT, MCP

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/ephemengine-com/). Scores are computed from the provider's own public artifacts under a published rubric.