FamilySearch

familysearch-mcp

An MCP server for genealogical research on FamilySearch: a historical place gazetteer, indexed record search, the page images behind the records, and reads of the shared family tree.

Nothing here writes to FamilySearch. The shared tree is community-edited and conflations of same-named people are common, so a tree result is a hint: follow it to the underlying record and cite that.

This is an independent project. It is not made, endorsed or supported by FamilySearch.

Credentials

This package ships no client id and never handles a FamilySearch password. Records, images and the tree need an access token from your own registered FamilySearch application; docs/AUTH.md explains why, and how to get one.

The gazetteer, the collection catalogue and the film browser answer without a token, so they work on a fresh install with no setup at all.

Install

uvx familysearch-mcp

That runs the server over stdio, which is how an MCP client starts it. You normally put it in the client's configuration rather than running it yourself.

Claude Desktop

{
  "mcpServers": {
    "familysearch": {
      "command": "uvx",
      "args": ["familysearch-mcp"],
      "env": { "FS_ENV_FILE": "/path/to/familysearch.env" }
    }
  }
}

Point at an env file rather than pasting the token into env. A token that lives in the client's config can only be replaced by editing it and restarting; a token in the file is picked up mid-session. With no token at all, leave env out and the anonymous tools still work.

Claude Code

claude mcp add familysearch -e FS_ENV_FILE=/path/to/familysearch.env -- uvx familysearch-mcp

Configuration

Variable	Meaning
FS_ACCESS_TOKEN	Bearer token from your application's OAuth flow.
FS_ENV_FILE	The env file to read these settings from, and to re-read a refreshed token from. Default: the nearest .env from the working directory upward.
FS_CLIENT_ID	Your registered application's client id, reported by auth_status.
FS_ENVIRONMENT	production (default) or integration for the FamilySearch sandbox.
FS_TIMEOUT	HTTP timeout in seconds. Default 60.

.env.example lists them with comments.

Tools

Twenty-eight tools. All of them read; download_image also writes the page it fetches to a local file.

Places

FamilySearch's Places API answers anonymously.

Tool	Needs a token	Purpose
search_places	no	Resolve a place name to its full jurisdictional form and coordinates.
search_places_at_date	no	Resolve a place as it was in a given year. A record naming a county that no longer exists is normal; filing it under the modern one is an invisible error.
get_place	no	Read one place: jurisdictional chain, type, coordinates, and the dates that jurisdiction existed.
get_place_jurisdictions	no	Walk the containment chain upward — what turns "Kaskaskia" into "Kaskaskia, Randolph, Illinois, United States".
get_place_children	no	The places directly inside a jurisdiction — the downward walk.

Records and collections

Tool	Needs a token	Purpose
search_records	yes	Search historical records by name, life events, parents, spouse, record type or collection. Every criterion filters. Returns one hit per record, with the others named on it.
get_record	yes	Read one indexed record in full: every person on it and the labelled fields behind each.
get_record_image	yes	Find the document image a record came from, or the film number when no image was published.
get_records_on_image	yes	Every record indexed from one image. A census page carries forty people.
fulltext_search	yes	Search the handwriting-recognised text of page images, mostly deeds, wills, probate and court files, for a name or phrase anywhere on the page. A machine reading: open the image and cite that.
search_collections	no	Find a record collection by title, with its coverage.
get_collection	no	Read one collection: what it covers and how much of it there is.
get_collection_fields	no	Decode a collection's indexed field codes (PR_FTHR_NAME → "Father's Name").
browse_waypoints	no	Browse a collection's volumes and films, to reach pages the index never covered.
get_catalog_entry	yes	Read a FamilySearch Catalog entry: title, authors, places, notes, and each film or DGS with its description, image count and whether you can view it. contains narrows an entry of thousands to the volume or case you want.

Page images

Tool	Needs a token	Purpose
get_image_links	for the page	Resolve an image ark to fetchable URLs: full page, deep zoom, thumbnails, neighbouring pages, and with a token the film and image number a citation needs. Without a token only the navigation comes back.
get_film_image	for the page	Reach a page by film and image number when a citation gives those instead of an ark. Checking the page exists needs no token.
download_image	yes	Download a page image to a new local file so it can be read.

Shared tree — a lead, never a source

Every tool here reads a community-edited profile, and says so in its own description.

Tool	Needs a token	Purpose
get_person	yes	Read a shared-tree person: names, sex, facts.
get_person_relatives	yes	Parents, spouses, children and siblings in one call.
get_person_sources	yes	What the tree attaches as sources, and which facts each supports. The fastest route out of the tree.
get_ancestry	yes	Pedigree walk back, up to 8 generations, numbered by Ahnentafel.
get_descendancy	yes	Pedigree walk forward, up to 4 generations.
get_person_memories	yes	Attached photographs, documents and stories.
get_person_changes	yes	The change log: who edited this profile, when, and why.
get_matches	yes	FamilySearch's own duplicate and record-match candidates.
compare_person	yes	Compare your own record of a deceased person with their profile: what agrees, what the profile lacks, what differs, and one proposed change per packet for you to make by hand.

Setup

Tool	Needs a token	Purpose
auth_status	no	Report what is configured, what is missing, and whether FamilySearch still accepts the token.

How it behaves

• The tree is not evidence. The tree tools read profiles anyone can edit. Use them to find records. get_person_sources is the most useful of them because it leads out of the tree towards a document.
• A comparison proposes; it never changes. compare_person takes your own names, events, relatives and sources for one person, reads the profile, and reports what agrees, what the profile lacks and what differs. Each proposed change comes as a packet: the source, the facts to tag it to, a draft reason with gaps for you to fill, and where on the website to make it. You make the change yourself, one at a time, after reading the record. It refuses anyone who may be living, and it never proposes combining profiles, removing anything, replacing a relationship or changing living status. See docs/COMPARE.md.
• A persona is not the record. A search returns one person's summary of what a record said; get_record returns the indexed fields behind it, and get_record_image the document itself. Read down that chain before citing.
• Jurisdictions move. search_places_at_date resolves a place as it was in a given year. Filing an 1820 record under the county that covers the ground today is a common and hard-to-spot error.
• Record search uses the website's search service. The API's own record search answers from a partial index that is almost all immigration records. search_records asks the service the FamilySearch website uses instead, with your token and a browser User-Agent, which that service requires. It is undocumented and FamilySearch can change or close it; docs/API-NOTES.md has the comparison.
• Full-text search is a machine reading. fulltext_search asks the website's full-text service, on the same footing as record search: your token, a browser User-Agent, and an undocumented route. Its text is handwriting recognition, so names and numbers are often misread; each hit gives the passages that matched and the page's image ark, and the page is what to read and cite. Only some collections and volumes have been machine-read, so no result proves nothing. Every word must match unless you write OR, because the service otherwise matches any one of them.
• The Catalog describes holdings, not records. get_catalog_entry reads the entry the website's catalog page reads, on the same footing as record search. For each film it reports the DGS number, which get_film_image and fulltext_search take, and asks the image store whether your account may view it and how many images it holds. A DGS is not the microfilm number; a film may be restricted or never digitised; and a description is a cataloguer's summary, so read the images and cite them.
• Search criteria filter. FamilySearch treats a search term as a ranking hint unless told otherwise, so adding a death year to a name search only reorders it. This server asks for every criterion to match; loose=True goes back to ranking.
• Tokens expire, and a refreshed one is picked up. A token lasts about an hour. On a 401 the server re-reads FS_ACCESS_TOKEN from the env file and retries once, so refreshing the file is enough. auth_status reports token_accepted: false when it is not.
• Throttling is retried once. A 429 asking for a wait of up to 15 seconds is waited out and retried. A longer wait, or a second 429, comes back as rate_limited with the server's Retry-After.
• Unknown parameters are refused. A misspelt or invented argument is an error that lists the parameters the tool does take. It is not silently dropped, which would make a filtered search quietly return unfiltered results.
• download_image is careful with what it is given. It fetches only HTTPS URLs on FamilySearch hosts, because the request carries your token. It creates only image and PDF files, and never overwrites one.
• Some routes are not publicly documented. FamilySearch's Historical Records API is behind a login wall, so those routes and response shapes were confirmed by live probing instead. A comment beside the code says when, and docs/API-NOTES.md records what was found. tests/live_check.py asks again.

Development

git clone https://github.com/ianderso/familysearch-mcp
cd familysearch-mcp
uv sync --extra dev
uv run pytest                  # mocked with respx; no token, no network
uv run ruff check .
uv run ruff format --check .

uv run python -m tests.live_check re-asks FamilySearch the questions only the live API can answer, with the token from your env file. See CONTRIBUTING.md for what a change is expected to carry.

License

MIT.