Overview

iNaturalist's index of 380M+ georeferenced citizen-science observations of plants, animals, and fungi. Search sightings by area, date, taxon, and annotation; read the community identification thread behind a record; chart when a taxon appears in a place; rank the species of an area; and check what a look-alike is most often confused with. Keyless and read-only, running as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Composes with servers covering institutional specimen records, botanical nomenclature, and geocoding — this one contributes the observation, identification-thread, and phenology layer.

Tools

Resources

Both resources mirror data also reachable through inaturalist_get_taxon and inaturalist_get_observation — useful for clients that don't surface MCP resources.

Capability reference

inaturalist_list_reference _tool

• topic selects one table: controlled_terms, quality_grades, licenses, ranks, iconic_taxa, conservation_status_codes; source reports whether it came from iNaturalist or the published spec
• taxon_id applies only to controlled_terms and adds observed_usage — which annotation pairs identifiers have actually recorded for that taxon, with counts. Each row carries term_id and term_value_id, ready to pass to the annotation filters; labels repeat across attributes ("Egg" is both a Life Stage and an Evidence of Presence value), so filter by the ids
• Every other tool's recovery hint routes here: an unrecognised filter value is not rejected upstream, it silently returns nothing

inaturalist_resolve_name _tool

• type: taxon (name-prefix autocomplete) or place / project / user / any (scored cross-kind search); rank narrows taxa only; limit 1–30 (default 10), applied in-process on every type
• Taxon lookup matches a name prefix, not words inside a name — "monarch" hits where "monarch butterfly" misses
• A miss is a result: found: false with guidance naming why, rather than an error
• Each candidate carries kind and id — the identifier every other tool takes. A user candidate also carries login, the value leaderboard entries and an observation's observer relay; its name is the display name

inaturalist_find_places _tool

• Exactly one of q (place-name prefix) or all four of nelat, nelng, swlat, swlng; neither or both fails as invalid_geography, as does a box with nelat south of swlat. A blank q reads as unset, and nelng west of swlng is an antimeridian-crossing box, not an error
• q returns places[]; the bounding box returns standard[] and community[] as separate lists
• Each place carries bbox, place_type, admin_level, ancestor_place_ids, location, and slug; boundary polygons are stripped, since one upstream response carries 247 KB of them
• per_page (1–30, default 10) binds the bounding-box arm only, where it bounds standard[] and community[] separately, so cap is per_page × 2. The name-prefix endpoint publishes no page size, and its fixed page is disclosed through the truncation enrichment

inaturalist_search_observations _tool

• An area is given in exactly one form — place_id, the lat+lng+radius triple in kilometres (0 < radius ≤ 500), or the four-corner bounding box with nelat at or north of swlat; partial, mixed, a zero radius, or an inverted box fails as invalid_geography
• Filters: taxon_id, d1/d2, quality_grade, captive, term_id+term_value_id, iconic_taxa, hrank/lrank, csi, threatened/native/introduced/endemic, user_id or user_login, project_id, licensed/photo_licensed, license/photo_license, and q+search_on
• user_id, user_login, and project_id come from inaturalist_resolve_name (a login also rides leaderboard entries and every observation's observer). Passing both observer forms fails as conflicting_observer; an unknown observer or project fails as unknown_user or unknown_project_id
• license and photo_license take licence codes — cc0, cc-by, cc-by-nc, cc-by-nd, cc-by-sa, cc-by-nc-nd, cc-by-nc-sa, any case — joined as OR, so ["cc-by","cc0"] finds sightings reusable with attribution only. photo_license matches a record with any photo under the code, independently of the record's own licence. licensed/photo_licensed only test for a non-null licence
• Ordered pairs are checked before the request: d1 after d2 fails as inverted_date_range (on every tool that takes dates), and an hrank finer than lrank as inverted_rank_range. Equal pairs are valid
• Defaults to quality_grade: ["research"] and captive: false, echoed back as applied_filters on every call
• per_page 1–25 (default 10); page walks the first 10,000 results under any ordering. Past that, order by id descending and pass each page's next_cursor as cursor — next_cursor is issued only on an id-descending page, since no other ordering can be continued by id. Passing page and cursor together fails, and a cursor forces the id ordering, which is echoed
• A page past the last one holding results says so and names that page, rather than suggesting wider filters
• include expands photos, annotations, sounds. identifications and comments are deliberately absent — one thread measures 28 KB, so the thread lives on inaturalist_get_observation

inaturalist_get_observation _tool