<div align="center"> <h1>@cyanheads/smithsonian-mcp-server</h1> <p><b>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.</b> <div>6 Tools</div> </p> </div>
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Public Hosted Server: https://smithsonian.caseyjhand.com/mcp
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Prerequisites
A free
api.data.govAPI key is required. Register at https://api.data.gov/signup — approval is instant. Set it asSMITHSONIAN_API_KEYin your MCP client config or.envfile. The server will not start without it. CC0 media gating:smithsonian_get_mediaonly returns CC0-licensed (open access) images. Usesmithsonian_search_objectswithfilters.cc0_only: trueto find objects with downloadable media before calling it.
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Tools
Six tools covering the full Smithsonian Open Access workflow — filter vocabulary discovery, search, detail retrieval, CC0 image access, and cross-collection exploration:
| Tool | Description | |:---|:---| | smithsonian_search_objects | Search across 14.5M objects by text query with optional filters (museum, type, date term, culture, place, topic, name, online-only, CC0). Returns curated summaries with total count. | | smithsonian_list_terms | Enumerate the valid term vocabulary for an indexed filter field (unit_code, culture, place, date, online_media_type, topic). Call before filtering to avoid empty results from invalid values; pass contains to resolve a guessed value to its exact term(s). unit_code terms come back with their museum names. | | smithsonian_get_object | Fetch a normalized catalog metadata projection for an object by ID: title, dates, materials, dimensions, exhibition history, credit line, and identifiers. | | smithsonian_get_media | Return all CC0-licensed images for an object at multiple resolutions (thumbnail, screen, high-res JPEG/TIFF). Only CC0 images returned, never an empty list — a distinct error reason names why, whether the object has nothing digitized, only non-image media, or only restricted images. | | smithsonian_browse_category | Browse objects within one exact category (museum, culture, period, medium, topic) with total count, a page of objects, and museum breakdown. Requires an exact indexed category term. | | smithsonian_find_related | Discover cross-collection objects related to an anchor, matched on shared culture, named-party, topic, and period signals. |
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 topicandnameare hard indexed constraints, not free text —topic: "Quilts"matches 1,134 objects where the bare word matches 2,677, andname: "Warhol, Andy"matches 421 against 715- Returns curated summaries: title, date, museum, object type, thumbnail URL, CC0 flag,
record_id - Use
start+rowsfor standard pagination (offset-based, max 100 per page)
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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.
PaintingsnotPainting) — grounding filter values here avoids empty results - Pass
containsto 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, alabelsmap returns each code's museum name andcontainsmatches that name as well as the code, soNational Air and Spaceresolves toNASMin one call - Paginate with
start+rows(default 50 per page, max 100); the largest vocabularies aretopic(133k terms) andplace(114k), so pair those withcontains - 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_typeis not enumerable upstream — discover object-type values from theobject_typefield insmithsonian_search_objectsresults
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smithsonian_get_object
Normalized catalog metadata for a single object.
- Input:
record_idfromsmithsonian_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_mediafor full image URLs
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smithsonian_get_media
CC0-gated image access at multiple resolutions.
- Only CC0-licensed images are returned; throws
Forbiddenwhen an object has media but none is CC0 - Throws
no_imageswhen 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_objectswithfilters.cc0_only: truebefore calling this tool
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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") valuemust be an exact indexed category term — resolvemuseum,culture,period, andtopicvocabulary withsmithsonian_list_termsfirst;object_typeis not enumerable there, so harvest it fromsmithsonian_search_objectsresults- 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+rowsfor 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_categorywith a mode-specific recovery hint. A value outside the vocabulary gets the exactsmithsonian_list_termscall 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
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smithsonian_find_related
Cross-collection discovery via shared metadata signals.
- Matches the anchor's culture, named-party, topic, and period+type metadata signals against the wider catalog
- The named-party signal carries the catalog's own role for the party (
maker,collector,donor,issuing authority, …) rather than a fixedmakerlabel, prefers the indexednamefacet 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 - Surfaces related objects from across collections, each tagged with the metadata signals that connected it to the anchor
- Cross-museum discovery is the differentiator — an NASM aerospace anchor may surface related objects from NMNH, SAAM, and NMAH
similarity_signalson each result show every metadata term that connected it to the anchor — an object surfaced by more than one signal carries all of them- Page past a truncated result with
start— a 0-indexed offset into the interleaved related set; page contiguously withstart = page × limit(each signal is reachable to a depth of 5,000, fetched in ≤1,000-row chunks; a deeper page can shift an object by a bounded amount near a seam). A truncated response reportstruncationCeilingas an upper bound on the reachable related pool signals[]breaks the fan-out down per signal:row_countis that signal's true upstream size (uncapped, so it can exceed the 5,000 reach) andsearch_continuationis the exactsmithsonian_search_objectsinput that retrieves the signal's full match set at any depth — the retrieval path past this tool's per-signal reach
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Features
Built on @cyanheads/mcp-ts-core:
- Declarative tool definitions — single file per tool, framework handles registration and validation
- Unified error handling — handlers throw, framework catches, classifies, and formats
- Pluggable auth:
none,jwt,oauth - Swappable storage backends:
in-memory,filesystem,Supabase,Cloudflare KV/R2/D1 - Structured logging with optional OpenTelemetry tracing
- STDIO and Streamable HTTP transports
Smithsonian-specific:
- Wraps the Smithsonian Open Access API (14.5M objects across 20+ museums, 5.2M carrying CC0 media) with a free
api.data.govkey - CC0 gating on
smithsonian_get_media— only open-access images returned, never restricted content - Graceful degradation in
smithsonian_find_related— a failure in one metadata signal doesn't abort the rest - Response normalization across heterogeneous museum metadata schemas
Agent-friendly output:
has_mediaon every object summary — agents can gate image download calls without an extra lookup (theis_cc0flag is the metadata license, which the Open Access corpus carries almost everywhere)- Typed error reasons (
no_results,invalid_filter,not_found,no_media,no_images,not_cc0,invalid_id) with recovery hints for each case similarity_signalson related-object results let agents explain why objects were surfacedtotal_counton all search responses enables agents to communicate result scope before paginating
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Getting started
Public Hosted Instance
A public instance is available at https://smithsonian.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:
{
"mcpServers": {
"smithsonian-mcp-server": {
"type": "streamable-http",
"url": "https://smithsonian.caseyjhand.com/mcp"
}
}
}
Self-Hosted / Local
Requires a free
api.data.govAPI key — register at https://api.data.gov/signup and setSMITHSONIAN_API_KEYin your config.
Add the following to your MCP client configuration file:
{
"mcpServers": {
"smithsonian-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/smithsonian-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info",
"SMITHSONIAN_API_KEY": "your-api-key"
}
}
}
}
Or with npx (no Bun required):
{
"mcpServers": {
"smithsonian-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/smithsonian-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info",
"SMITHSONIAN_API_KEY": "your-api-key"
}
}
}
}
Or with Docker:
{
"mcpServers": {
"smithsonian-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"-e", "SMITHSONIAN_API_KEY=your-api-key",
"ghcr.io/cyanheads/smithsonian-mcp-server:latest"
]
}
}
}
For Streamable HTTP, set the transport and start the server:
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 SMITHSONIAN_API_KEY=your-api-key bun run start:http
# Server listens at http://localhost:3010/mcp
Prerequisites
- Bun v1.3.0 or higher (or Node.js v24+).
- A free
api.data.govAPI key — register at https://api.data.gov/signup. Approval is instant.
Installation
- Clone the repository:
git clone https://github.com/cyanheads/smithsonian-mcp-server.git
- Navigate into the directory:
cd smithsonian-mcp-server
- Install dependencies:
bun install
- Configure environment:
cp .env.example .env
# Edit .env and set SMITHSONIAN_API_KEY
---
Configuration
| Variable | Description | Default | |:---------|:------------|:--------| | SMITHSONIAN_API_KEY | Required. Free API key from api.data.gov/signup. | — | | SMITHSONIAN_BASE_URL | Smithsonian Open Access API base URL. | https://api.si.edu/openaccess/api/v1.0 | | SMITHSONIAN_TERMS_CACHE_TTL_SECONDS | Seconds to cache each indexed field's term vocabulary. 0 disables caching. | 3600 | | MCP_TRANSPORT_TYPE | Transport: stdio or http. | stdio | | MCP_HTTP_PORT | Port for HTTP server. | 3010 | | MCP_AUTH_MODE | Auth mode: none, jwt, or oauth. | none | | MCP_LOG_LEVEL | Log level (RFC 5424). | info | | LOGS_DIR | Directory for log files (Node.js only). | <project-root>/logs | | STORAGE_PROVIDER_TYPE | Storage backend. | in-memory | | OTEL_ENABLED | Enable OpenTelemetry instrumentation. | false |
See .env.example for the full list of optional overrides.
---
Running the server
Local development
- Build and run:
# One-time build
bun run rebuild
# Run the built server
bun run start:stdio
# or
bun run start:http
- Run checks and tests:
bun run devcheck # Lint, format, typecheck, security
bun run test # Vitest test suite
bun run lint:mcp # Validate MCP definitions against spec
Docker
docker build -t smithsonian-mcp-server .
docker run --rm -e SMITHSONIAN_API_KEY=your-api-key -p 3010:3010 smithsonian-mcp-server
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/smithsonian-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.
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Project structure
| Directory | Purpose | |:----------|:--------| | src/index.ts | createApp() entry point — registers tools and initializes the Smithsonian service. | | src/config | Server-specific environment variable parsing (SMITHSONIAN_API_KEY, SMITHSONIAN_BASE_URL, SMITHSONIAN_TERMS_CACHE_TTL_SECONDS). | | src/mcp-server/tools | Tool definitions (*.tool.ts). | | src/services/smithsonian | Smithsonian Open Access API client, normalization, and type definitions. | | tests/ | Unit and integration tests. | | docs/ | Design document and directory tree. |
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Development guide
See CLAUDE.md / AGENTS.md for development guidelines and architectural rules. The short version:
- Handlers throw, framework catches — no
try/catchin tool logic - Use
ctx.logfor request-scoped logging,ctx.statefor tenant-scoped storage - Register new tools via the barrel in
src/mcp-server/tools/definitions/index.ts - Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields
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Contributing
Issues and pull requests are welcome. Run checks and tests before submitting:
bun run devcheck
bun run test
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License
Apache-2.0 — see LICENSE for details.











