Astrology API Directory: Best APIs for Astrology Apps and Widgets

If you are building an astrology app, a horoscope widget, or any tool that needs accurate planetary positions, you need a dedicated calculation API. This is not a job for a general-purpose language model. An LLM will generate plausible-sounding chart interpretations and quietly get the degrees wrong. Swiss Ephemeris - the calculation library that professional astrology software has run on since 1997 - has a positional accuracy of under one arc second. That is the standard. Any API worth using is either wrapping Swiss Ephemeris directly or sourcing from equivalent precision data.

This directory covers the real options available in 2026 for developers building on top of astrology data.

Why specialized APIs exist

Generic geocoding and date APIs do not understand the domain. A planetary position depends on the observer's latitude and longitude, the exact time down to the minute, and the correct ephemeris calculation method (tropical vs. sidereal, Placidus vs. whole-sign houses). Get any of those inputs wrong and the chart is wrong. These look like implementation details. To a professional astrologer, they are the product.

The APIs below handle these specifics. They each make different tradeoffs around accuracy method, supported chart types, output format, and price.

Astrology API Options

Astro.com (Astrodienst)

Astro.com is the reference implementation. The site runs on Swiss Ephemeris, which Astrodienst themselves developed and open-sourced. They do not offer a commercial REST API - their calculation engine is available directly as the open-source `swisseph` C library, with Python bindings (`pyswisseph`) and wrappers available for most languages.

Best for: Teams with a backend engineer who can integrate a C library or its language bindings. Full control over ephemeris method, house system, and output format. No rate limits, no vendor dependency, no API cost beyond server compute.

Not for: Teams that want a REST endpoint and JSON back in 15 minutes.

Pricing: Free and open-source (AGPL). Commercial license available from Astrodienst if AGPL is incompatible with your project.

AstrologyAPI.com

A hosted REST API built on Swiss Ephemeris, returning JSON. Covers natal charts, transit charts, synastry, solar return, and Vedic (sidereal) charts. Supports 11 house systems. Returns raw planetary degrees, sign placements, aspects, and pre-formatted interpretation text for common placements.

Best for: Web and mobile apps that need a managed endpoint and can use pre-built interpretation text. Good fit for consumer-facing horoscope features where you want both data and copy in one call.

Pricing: Tiered by API calls. Free tier available (limited calls/month). Paid plans start at approximately $30-$80/month depending on volume. Pricing is on their site and subject to change.

Note: Interpretation text is generic by design. It works for daily horoscope copy. It is not a substitute for a practitioner's reading.

Prokerala API

Prokerala offers both Western astrology and Vedic (Jyotish) endpoints. Coverage includes natal chart, Kundli, Panchang, auspicious timing (Muhurta), compatibility reports, and transit data. Strong Vedic feature set - house lords, Dasha periods, Yoga calculations - that most Western-focused APIs do not cover.

Best for: Apps targeting South Asian markets or practitioners working in Jyotish. The Panchang endpoint is genuinely useful for apps that display daily Vedic almanac data.

Pricing: Free tier with rate limits. Paid plans available. Documentation on prokerala.com.

Astrologer.io

A developer-focused astrology API with a clean REST interface. Returns chart data as structured JSON with planetary positions, house cusps, aspects, and some interpretation fields. Supports tropical and sidereal zodiac. Less feature breadth than AstrologyAPI.com but the response schema is straightforward to work with.

Best for: Developers who want minimal output to parse and are building their own interpretation layer. Useful for embedding chart data into a custom UI without carrying along interpretation text you do not need.

Pricing: Check current plans at astrologer.io - pricing has changed over time.

Swiss Ephemeris (direct, open-source)

Not an API service - the source library. `swisseph` is the C library that most of the commercial APIs wrap. Available on GitHub under AGPL. Python bindings via `pyswisseph`. Node.js wrappers exist but are less maintained. If you are running your own backend, building directly on `swisseph` eliminates all API vendor risk and rate limits.

Best for: Teams building their own calculation service, or embedding chart math into an existing Python/Node backend. Full control, zero ongoing cost.

Not for: Frontend-only projects or teams without backend capacity.

Tarot API Options

Tarot APIs are a different problem. A tarot draw is random card selection plus card data (name, suit, keywords, image). There is no Swiss Ephemeris equivalent - accuracy means card data quality, not calculation precision.

Tarot API (tarotapi.dev)

A free public REST API. Returns the 78-card deck with card name, suit, element, keywords, and a short description for each card. No account required. Can randomize draws. Primarily useful for prototyping or hobby projects.

Best for: Getting a working daily card draw into a prototype in an afternoon.

Limitations: Card data quality is basic. No spread logic, no reversals in all implementations. Not suitable as a production dependency for a paid product without caching the dataset locally.

Build your own (recommended for production)

For any production tarot feature, pulling card data from a third-party endpoint at runtime is unnecessary overhead with no upside. The full 78-card dataset is a small JSON file. Maintain your own data layer with the card attributes you need - name, number, suit, arcana, keywords, image reference - and handle randomization server-side. This is what every production tarot app does.

How to choose

Accuracy requirement: If your app serves professional astrologers or generates paid reports, Swiss Ephemeris precision is non-negotiable. Use `swisseph` directly or verify that the API you choose explicitly documents Swiss Ephemeris as the calculation source.

REST vs. library: A hosted API is faster to integrate and requires no backend infrastructure. A direct library integration (`swisseph`) has no rate limits, no vendor risk, and no per-call cost at scale. The crossover point where library integration wins economically is lower than most teams expect.

Vedic vs. Western: Most APIs focus on Western tropical astrology. If you need Jyotish calculations - Kundli, Dasha, Muhurta, Navamsha - check Vedic coverage explicitly. Prokerala has the strongest Vedic feature set among hosted APIs.

Rate limits and widget use: If you are powering a widget that serves many end users, check whether the API pricing model is per-call or per-seat. Per-call pricing on a high-traffic widget adds up. Consider whether caching daily or hourly ephemeris data reduces your call volume.

--- Find astrology widgets and tools that use these APIs in production at our store. If you are new to the EsoTech tool landscape, what is EsoTech is a useful starting point.

Looking to ship astrology features rather than wire APIs yourself? Esotier offers ready-made, embeddable astrology and divination widgets plus author-built engines — the practical alternative to integrating raw APIs, and part of the EsoTech infrastructure.