Ranked by the provider's API Evangelist rating — the Kin Score is scored per provider, not per API, so every API of a provider shares its band. How the rating works →

Exemplar 1 Complete, well-documented, and agent-ready

CycleCalcs MCP ServerHosted stateless Streamable HTTP MCP server exposing 11 astronomy tools backed by the v2 REST endpoints. To...67.1

Developing 2 Usable, with meaningful gaps to close

IPGeolocation.io Astronomy APIAPI endpoints for retrieving astronomical information for a given location, including sunrise and sunset ti...42.8 Stormglass Astronomy APISolar and lunar astronomical data including sunrise, sunset, moon phases39.3

Thin 1 Limited public surface area

Astronomy APIThe Astronomy API provides access to astronomical data including celestial body positions, moon phases, pla...37.4

Emerging 6 Early or largely undocumented

ESA Gaia Archive TAP APITable Access Protocol (TAP) service for the ESA Gaia stellar catalogue, the most precise astrometric survey...23.8 ESASky Legacy TAP ServiceIVOA Table Access Protocol (TAP) service providing access to ESA legacy mission archives including Hipparco...23.8 IRSA Virtual Observatory APIs (Caltech/IPAC)The NASA/IPAC Infrared Science Archive exposes IVOA-standard Virtual Observatory interfaces — Table Access ...22.9 NASA Exoplanet Archive TAP (Caltech/IPAC)The NASA Exoplanet Archive, operated by Caltech/IPAC, exposes an IVOA TAP service over its confirmed-planet...22.9 NED Table Access Protocol (Caltech/IPAC)The NASA/IPAC Extragalactic Database, operated by Caltech/IPAC, exposes an IVOA TAP service over its extrag...22.9 James Webb Space Telescope APIProgrammatic access to JWST images and observations sourced from the MAST archive. Filter and query by prog...15.1

Score breakdown

Frequency

38.8

log-scaled weighted occurrences

Breadth

0.4

spread across providers

Quality lift

30.4

mean composite of providers using it

Cohesion

0.7

strength of nearest seed neighbor

Where this tag comes from

Provider tag17

Api tag10

Openapi tag1

Openapi op tag1

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find_tagsBrowse and filter every tag in the catalog.
get_cohortThis tag as a scored cohort — every provider carrying it, with scores.
cohort_statsPRO — the distribution across this tag: mean, median, band split, adoption rates.
cohort_rankingsPRO — the leaderboard, on composite AND agent-readiness axes.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

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Call it yourself

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This tag

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All tags

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As a scored cohort

curl "https://apis.io/api/v1/cohorts/tag/astronomy"

The distribution (Pro)

curl "https://apis.io/api/v1/cohorts/tag/astronomy/stats" \
  -H "X-API-Key: $APIS_IO_KEY"

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Astronomy

Providers using this tag (17)

APIs with this tag (10)