Prerequisites

A free api.data.gov API key is required. Register at https://api.data.gov/signup — approval is instant. Set it as SMITHSONIAN_API_KEY in your MCP client config or .env file. The server will not start without it.

CC0 media gating: smithsonian_get_media only returns CC0-licensed (open access) images. Use smithsonian_search_objects with filters.cc0_only: true to find objects with downloadable media before calling it.

Tools

Six tools covering the full Smithsonian Open Access workflow — filter vocabulary discovery, search, detail retrieval, CC0 image access, and cross-collection exploration:

smithsonian_search_objects

Full-text search with structured filters across the entire Smithsonian catalog.

• Free-text search over 14.5M objects from 20+ museums
• Filters: museum unit code, object type, indexed date term (1920s, 500-1500, 21st century, -2500), culture, geographic place, subject topic, named party (name), online-only, CC0-only
• topic and name are hard indexed constraints, not free text — topic: "Quilts" matches 1,134 objects where the bare word matches 2,677, and name: "Warhol, Andy" matches 421 against 715
• Returns curated summaries: title, date, museum, object type, thumbnail URL, CC0 flag, record_id
• Use start + rows for standard pagination (offset-based, max 100 per page)

smithsonian_list_terms

Enumerate the valid term vocabulary for an indexed filter field before applying filters.

• Supported fields: unit_code, culture, place, date, online_media_type, topic
• Returns the field's distinct term values as a page of the full vocabulary — no per-term object counts are available upstream
• Smithsonian uses a controlled vocabulary (terms are often plural, e.g. Paintings not Painting) — grounding filter values here avoids empty results
• Pass contains to filter the vocabulary by a case-insensitive substring — resolve a guessed value (e.g. greek → Greek, Attic) to its exact term(s) in one call, or confirm absence with an empty result
• For unit_code, a labels map returns each code's museum name and contains matches that name as well as the code, so National Air and Space resolves to NASM in one call
• Paginate with start + rows (default 50 per page, max 100); the largest vocabularies are topic (133k terms) and place (114k), so pair those with contains
• Each field's vocabulary is cached for SMITHSONIAN_TERMS_CACHE_TTL_SECONDS (default 1 hour) — upstream ignores paging and returns the whole set on every call, so paging a large vocabulary uncached re-downloads it each time
• object_type is not enumerable upstream — discover object-type values from the object_type field in smithsonian_search_objects results

smithsonian_get_object

Normalized catalog metadata for a single object.

• Input: record_id from smithsonian_search_objects — do not construct IDs manually
• Returns the exposed catalog fields: title, dates (all labeled), makers (with roles), materials, dimensions, place associations, culture terms, topic/subject terms, exhibition history, accession identifiers, credit line, rights statement
• Media summary included — call smithsonian_get_media for full image URLs

smithsonian_get_media

CC0-gated image access at multiple resolutions.

• Only CC0-licensed images are returned; throws Forbidden when an object has media but none is CC0
• Throws no_images when an object's media is entirely non-image (scanned books, 3D models, sound recordings); the recovery hint names the types present
• Each image entry includes thumbnail (~120px), screen-size (~800px), and high-resolution JPEG/TIFF URLs with pixel dimensions
• Use smithsonian_search_objects with filters.cc0_only: true before calling this tool

smithsonian_browse_category

Paginated browse within one exact category. For open-ended or topic discovery, use smithsonian_search_objects instead.

• Five modes: museum (by unit code, e.g. "NASM" — matched exactly, not by museum name), culture (e.g. "Aztecs"), period (indexed date term, e.g. "1940s" or "500-1500"), medium (object type, e.g. "Paintings"), topic (subject term, e.g. "Quilts")
• value must be an exact indexed category term — resolve museum, culture, period, and topic vocabulary with smithsonian_list_terms first; object_type is not enumerable there, so harvest it from smithsonian_search_objects results
• Returns total count, a page of sample objects, and a museum breakdown showing which institutions hold matching items (computed from the current page)
• Use start + rows for standard pagination (offset-based, start = page × rows, max 50 per page) — adjacent pages retrieve the objects a capped sample omits
• A category value that matches nothing throws invalid_category with a mode-specific recovery hint. A value outside the vocabulary gets the exact smithsonian_list_terms call that resolves it; a value the index enumerates but that matches no objects is named as such and routed elsewhere, since resolving it returns the same value

smithsonian_find_related

Cross-collection discovery via shared metadata signals.