Smithsonian MCP Server

@cyanheads/smithsonian-mcp-server Search 14.5M Smithsonian Open Access objects across 20+ museums via MCP, and retrieve CC0 images for the 5.2M that carry openly-licensed media. STDIO or Streamable HTTP. 6 Tools

Public Hosted Server: https://smithsonian.caseyjhand.com/mcp

Overview

The Smithsonian's Open Access catalog: 14.5 million objects across 20+ museums, 5.2 million with CC0 images. Search by free text or category, browse by museum, culture, date, or topic, and discover connections across collections.

Tools

Skill

Ships in skills/ for plugin installs, the npm package, the Docker image, and the .mcpb bundle, and is served over MCP as skill://smithsonian-guide/SKILL.md.

Capability reference

smithsonian_search_objects tool

• Free-text search over 14.5M objects from 20+ museums
• Filters append hard AND constraints. Plain words and quoted phrases keep their matching semantics; active Lucene expressions are grouped to preserve Boolean precedence.
• filters.online_media_type accepts exact smithsonian_list_terms media categories such as Images, 3D Models, and Sound recordings. These describe the index; even Images does not guarantee attached or CC0 images. Check smithsonian_get_object.media_summary for deliverability. Media categories feed search, with no media-type browse mode.
• Filters: museum unit code, object type, indexed date term (1920s, 500-1500, 21st century, -2500), culture, geographic place, subject topic, named party (name), scientific name (scientific_name), indexed media category (online_media_type), 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, plus holding_museum_name when the holding unit differs from the indexed unit_code (the 3D digitization scans)
• An unknown filters key is rejected by name
• Use start + rows for standard pagination (offset-based, default 20, up to 1,000 per page — a larger rows is served at 1,000 with a notice). When objects remain, the notice names the next start

smithsonian_list_terms tool

• Fields: unit_code, culture, place, date, online_media_type, topic — a controlled vocabulary, often plural (e.g. Paintings, not Painting); ground filter values here before searching or browsing
• contains filters the vocabulary by a case-insensitive substring — resolves a guessed value (e.g. greek → Greek, Attic) in one call; for unit_code it also matches museum names (National Air and Space → NASM), and each unit_code term comes back with a labels map of its museum name
• Paginate with start + rows (default 50, up to 40,000 per page — a larger rows is served at 40,000 with a notice); topic (133k terms) and place (114k) are large enough to pair with contains
• No per-term object counts are available upstream — only the term values themselves
• Each field's vocabulary is cached for SMITHSONIAN_TERMS_CACHE_TTL_SECONDS (default 3600 seconds, 0 disables) — 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 here — harvest its values from the object_type field in smithsonian_search_objects results

smithsonian_get_object tool

• 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. media_summary.non_image_media[] lists every media item that is not an image (3D models, scanned books, documents) as { type, url?, is_cc0 }, in catalog order
• holding_museum_name names the holding unit when it differs from unit_code, the code the record is indexed under (the 3D digitization scans); the text output renders it as Held by
• All nonempty notes retain their catalog labels and source order. description selects recognized prose labels; administrative notes stay labeled.
• Natural-history metadata includes all scientific_names, reported taxonomy ranks, and valid decimal collection coordinates with their own locality when present. The arrays are empty when no names or valid points are available; absent ranks are omitted. No accepted name, geocoding, or accuracy is inferred. Use scientific_names as exact filters.scientific_name values in search; this field is not enumerable via smithsonian_list_terms.

smithsonian_get_media tool

• Only CC0-licensed images are returned, never restricted content
• Three distinct failure reasons when nothing is returnable: no_media (nothing digitized), no_images (media exists but is entirely non-image — 3D models, scanned books, documents; the recovery hint names the types present and points to smithsonian_get_object's media_summary.non_image_media, which links each item), not_cc0 (images exist but none are CC0, thrown as Forbidden)
• 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 to find objects with downloadable CC0 images before calling this tool

smithsonian_browse_category tool

• 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, default 10, up to 1,000 per page — a larger rows is served at 1,000 with a notice). When objects remain, the notice names the next start — 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, and a value the index enumerates but that matches no objects is named as such and routed elsewhere
• For open-ended or topic discovery, use smithsonian_search_objects instead — this tool requires an exact category value

smithsonian_find_related tool

• Matches shared culture, named-party, topic, and period+type metadata signals against the wider catalog; cross-museum discovery is the differentiator — an NASM aerospace anchor may surface related objects from NMNH, SAAM, and NMAH
• The named-party signal carries the catalog's own role for the party (maker, collector, donor, issuing authority, …) rather than a fixed maker label, prefers the indexed name facet as a hard filter when the record has one, and is dropped when its value only repeats the culture signal
• The topic signal is a hard topic: filter, so every object it tags carries that subject term rather than merely mentioning the word
• similarity_signals on each result names every metadata term that conne