transkribus-mcp-server

MCP server for the Transkribus REST API. Manage collections, documents, HTR/OCR recognition, models, and more through the Model Context Protocol.

304 tools across 23 resource domains, with 9 entry points so you can pick the right server for your MCP client's tool limit.

API scope: This server covers two Transkribus APIs:

• the legacy TrpServer REST API (https://transkribus.eu/TrpServer/rest), session-based — 300 tools;
• the Metagrapho Processing API (https://transkribus.eu/processing/v1), OIDC bearer auth via account.readcoop.eu — the 4 transkribus_processing_* tools.

Mind the version. Some Transkribus material still shows /processing/v2 and a config.modelId field. That path returns 404; the live service is /processing/v1 and takes config.textRecognition.htrId.

Installation

npm install -g @lazyants/transkribus-mcp-server

Or run directly:

npx @lazyants/transkribus-mcp-server

Configuration

Transkribus uses session-based authentication. Credentials are resolved in this order, per value:

1. OS keyring (recommended — nothing is written to a config file in clear text)
2. Environment variable (TRANSKRIBUS_USER + TRANSKRIBUS_PASSWORD, or TRANSKRIBUS_SESSION_ID)

Either a user name and password (the server logs in and manages the session) or a session id you already hold. A session id takes precedence when both are available; it expires, so a user name and password is the better choice for a long-running setup — and is what lets the server re-authenticate after a 401.

The keyring is never required: if it is unavailable — a headless Linux box with no Secret Service, an unsupported platform, an install with --omit=optional — or if it does not answer within 5 seconds, the server falls back to the environment.

Store the credentials in the OS keyring

Three entries under one service name, transkribus-mcp by default: user, password and session-id (store only what you use).

[!IMPORTANT] The commands below read the value from an interactive prompt rather than taking it as an argument, so it never lands in your shell history, in a command line, or in the launch environment of another process. Avoid pasting a password directly onto the command line.

macOS

Omitting the value after -w makes security prompt for it:

security add-generic-password -s "transkribus-mcp" -a "user" -w
security add-generic-password -s "transkribus-mcp" -a "password" -w

[!NOTE] A login-keychain item belongs to the program that created it. The first time the server reads an item created by security, macOS shows a "…wants to use your confidential information stored in transkribus-mcp" dialog — choose Always Allow and it will not ask again. Until that is granted the read cannot complete: the server waits 5 seconds, then falls back to the environment variables, so a server started where nobody can answer the dialog behaves as if the keyring were empty rather than hanging.

To avoid the dialog entirely, write the entry from the same Node.js runtime that will read it. The value is piped in on standard input, so it appears neither in a command line nor in a process environment (ps -E shows those). The prompt below is plain POSIX, so it behaves the same in zsh and bash:

npm install -g @lazyants/transkribus-mcp-server   # the keyring module ships with it
cd "$(npm root -g)/@lazyants/transkribus-mcp-server"
printf 'Transkribus password: ' >&2; stty -echo; IFS= read -r TK_SECRET; stty echo; printf '\n' >&2
printf '%s' "$TK_SECRET" | node -e '
  const { Entry } = require("@napi-rs/keyring");
  let value = "";
  process.stdin.setEncoding("utf8");
  process.stdin.on("data", (chunk) => { value += chunk; });
  process.stdin.on("end", () => {
    new Entry("transkribus-mcp", "password").setPassword(value);
    console.log("stored");
  });
'
unset TK_SECRET

Repeat with "user" in place of "password". A different Node.js installation later (a nvm switch, say) is a different program to the keychain, so the dialog can appear once more for it.

Windows (PowerShell)

cmdkey can only take the value as a command-line argument, which exposes it in the process list. Read it from a hidden prompt instead and write it straight into Windows Credential Manager via CredWrite. The credential's target name is <account>.<service> — user.transkribus-mcp and password.transkribus-mcp for the default service — which is exactly what the server reads back:

Add-Type -Namespace TranskribusKeyring -Name Native -MemberDefinition @'
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct CREDENTIAL {
    public uint Flags;
    public uint Type;
    [MarshalAs(UnmanagedType.LPWStr)] public string TargetName;
    [MarshalAs(UnmanagedType.LPWStr)] public string Comment;
    public System.Runtime.InteropServices.ComTypes.FILETIME LastWritten;
    public uint CredentialBlobSize;
    public IntPtr CredentialBlob;
    public uint Persist;
    public uint AttributeCount;
    public IntPtr Attributes;
    [MarshalAs(UnmanagedType.LPWStr)] public string TargetAlias;
    [MarshalAs(UnmanagedType.LPWStr)] public string UserName;
}
[DllImport("advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern bool CredWriteW(ref CREDENTIAL credential, uint flags);
'@

function Set-TranskribusCredential {
    param([Parameter(Mandatory)][string]$Account, [Parameter(Mandatory)][string]$Prompt)
    $secure = Read-Host -AsSecureString $Prompt
    $blob = [Runtime.InteropServices.Marshal]::SecureStringToCoTaskMemUnicode($secure)
    try {
        $cred = New-Object TranskribusKeyring.Native+CREDENTIAL
        $cred.Type = 1                                  # CRED_TYPE_GENERIC
        $cred.Persist = 2                               # CRED_PERSIST_LOCAL_MACHINE
        $cred.TargetName = "$Account.transkribus-mcp"   # "<account>.<service>"
        $cred.UserName = $Account
        $cred.CredentialBlob = $blob
        $cred.CredentialBlobSize = $secure.Length * 2   # UTF-16 bytes, no terminator
        if (-not [TranskribusKeyring.Native]::CredWriteW([ref]$cred, 0)) {
            throw "CredWrite failed (Win32 error $([Runtime.InteropServices.Marshal]::GetLastWin32Error()))"
        }
        Write-Host "Stored '$Account' in Windows Credential Manager."
    } finally {
        [Runtime.InteropServices.Marshal]::ZeroFreeCoTaskMemUnicode($blob)
        $secure.Dispose()
        Remove-Variable secure, blob
    }
}

Set-TranskribusCredential -Account 'user' -Prompt 'Transkribus user (e-mail)'
Set-TranskribusCredential -Account 'password' -Prompt 'Transkribus password'

Using a custom TRANSKRIBUS_KEYRING_SERVICE (e.g. acme)? Set TargetName to user.acme / password.acme to match — the server looks each value up under <account>.<service>.

Linux

secret-tool store --label="Transkribus user" service transkribus-mcp username user
secret-tool store --label="Transkribus password" service transkribus-mcp username password
# (each prompts for the value)

Once stored, MCP config files need no credentials at all.

Use environment variables instead

export TRANSKRIBUS_USER=your-email@example.com
export TRANSKRIBUS_PASSWORD=your-password

Or, with a session you already hold:

export TRANSKRIBUS_SESSION_ID=your-session-id

Environment variables

Processing API credentials

The transkribus_processing_* tools talk to a different service with a different auth scheme, but they need no extra configuration: the same TRANSKRIBUS_USER + TRANSKRIBUS_PASSWORD are exchanged for an OIDC bearer token (READCOOP SSO password grant, client processing-api-client) and refreshed automatically. TRANSKRIBUS_SESSION_ID does not apply to them.

Two optional overrides:

export TRANSKRIBUS_ACCESS_TOKEN=your-bearer-token       # skip the token exchange entirely
export TRANSKRIBUS_PROCESSING_CLIENT_ID=custom-client   # non-default OIDC client

Entry Points

Use split servers to reduce context size — pick only the splits you need.

Uploading a document

To ingest a document, use this three-step flow:

1. transkribus_upload_create_structure — give it collId, a title, and a pages array of { fileName, pageNr } (one entry per page image you are about to send). Returns an upload with an uploadId.
2. transkribus_upload_page — call once per page with the uploadId and imagePath (a path to a local image file), optionally pageXmlPath for an existing PAGE XML transcript.
3. transkribus_upload_get_status — poll with the uploadId until the document appears in the collection.

These upload tools ship in the full transkribus-mcp-server and in the transkribus-mcp-admin split — not in transkribus-mcp-collections. PDF ingestion is not supported; convert the PDF to page images first and use the flow above.

Claude Code

Add to ~/.claude/settings.json. With the credentials in the OS keyring under the default service name (recommended), no env key is needed:

{
  "mcpServers": {
    "transkribus": {
      "command": "npx",
      "args": ["-y", "@lazyants/transkribus-mcp-server"]
    }
  }
}

Or use split servers (pick the splits you need):

{
  "mcpServers": {
    "transkribus-collections": {
      "command": "npx",
      "args": ["-y", "-p", "@lazyants/transkribus-mcp-server", "transkribus-mcp-collections"]
    },
    "transkribus-transcription": {
      "command": "npx",
      "args": ["-y", "-p", "@lazyants/transkribus-mcp-server", "transkribus-mcp-transcription"]
    }
  }
}

Two Transkribus accounts at once — one instance per account, each pointed at its own keyring service name:

{
  "mcpServers": {
    "transkribus-team-a": {
      "command": "npx",
      "args": ["-y", "@lazyants/transkribus-mcp-server"],
      "env": { "TRANSKRIBUS_KEYRING_SERVICE": "transkribus-team-a" }
    },
    "transkribus-team-b": {
      "command": "npx",
      "args": ["-y", "@lazyants/transkribus-mcp-server"],
      "env": { "TRANSKRIBUS_KEYRING_SERVICE": "transkribus-team-b" }
    }
  }
}

Without a keyring, pass the credentials in env instead:

{
  "mcpServers": {
    "transkribus": {
      "command": "npx",
      "args": ["-y", "@lazyants/transkribus-mcp-server"],
      "env": {
        "TRANSKRIBUS_USER": "your-email@example.com",
        "TRANSKRIBUS_PASSWORD": "your-password"
      }
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json. With the credentials in the OS keyring (recommended — assumes the default service name transkribus-mcp):

{
  "mcpServers": {
    "transkribus": {
      "command": "npx",
      "args": ["-y", "@lazyants/transkribus-mcp-server"]
    }
  }
}

Without a keyring:

{
  "mcpServers": {
    "transkribus": {
      "command": "npx",
      "args": ["-y", "@lazyants/transkribus-mcp-server"],
      "env": {
        "TRANSKRIBUS_USER": "your-email@example.com",
        "TRANSKRIBUS_PASSWORD": "your-password"
      }
    }
  }
}

Security

• Use the OS keyring to keep your password out of config files and shell history entirely (see Configuration)
• Never commit your credentials to version control
• Session IDs expire — prefer a user name and password for long-running setups; a session id alone cannot be renewed after a 401

Disclaimer

This is an unofficial MCP server for Transkribus. The authors are not affiliated with READ-COOP SCE. Use at your own risk.

Releasing

Releases ship via the GitHub Release event. Maintainer flow:

1. Bump the version in package.json, package-lock.json, and server.json (npm version <x.y.z> --no-git-tag-version updates the first two together). npm run check-versions hard-fails unless package.json#/version and server.json#/packages[0].version agree. server.json#/version is checked loosely: it must be present, and it only fails when it regresses below packages[0].version — a value left behind at the previous release passes with a WARN: line and exit 0. The script does not look at package-lock.json or CHANGELOG.md at all, so read its output rather than trusting its exit code.

2. Update CHANGELOG.md.

3. Commit, and merge the version bump to main before creating the release. Then create the tag yourself, on a SHA you have checked, and only then create the release from it:

   V=X.Y.Z && PR=<release-pr-number> &&
     SHA="$(gh pr view "$PR" --json mergeCommit -q .mergeCommit.oid)" && test -n "$SHA" &&
     git fetch origin main && git merge-base --is-ancestor "$SHA" origin/main &&
     PKG="$(git show "$SHA:package.json")" &&
     test "$(printf '%s' "$PKG" | node -pe 'JSON.parse(require("fs").readFileSync(0,"utf8")).version')" = "$V" &&
     CL="$(git show "$SHA:CHANGELOG.md")" &&
     printf '%s\n' "$CL" | awk -v v="$V" 'index($0,"## ["v"]")==1{f=1;next} /^## \[/{f=0} /^\[[0-9]+\.[0-9]+\.[0-9]+\]:/{f=0} f' > "/tmp/notes-v$V.md" &&
     grep -q '[^[:space:]]' "/tmp/notes-v$V.md" &&
     git tag -a "v$V" "$SHA" -m "v$V" &&
     git push origin "v$V" &&
     gh release create "v$V" --verify-tag --notes-file "/tmp/notes-v$V.md"
   

   The failure this prevents: with no existing tag, gh release create vX.Y.Z places one on the tip of the default branch. Run it while the bump is still on a release branch and it tags the previous release's commit; the workflow then publishes whatever version it finds in that commit's package.json, producing a vX.Y.Z GitHub Release that silently republishes the old version. The publish workflow now refuses to continue when GITHUB_REF_NAME is not v<package.json version>, so that exact scenario fails before npm publish rather than silently republishing. The sequence above is still required, and guards a case the workflow cannot: the workflow guard only runs once a release already exists, and it passes for any commit carrying the right version — so it catches a mis-tagged release, not the wrong commit being tagged.

   Each element is load-bearing:

   • gh pr view … .mergeCommit.oid names the release PR's own squash commit. Do not substitute git rev-parse origin/main: that is merely whatever sits on main at the moment you look, so an unrelated merge landing in the gap gets tagged and shipped instead. gh exits 0 and prints nothing for an unmerged PR, hence the explicit test -n.
   • The && chain stops at the first failure instead of falling through to the irreversible step. Both git show calls are assigned to a variable rather than piped directly, so their exit status is actually checked — a pipeline reports only its last command's status unless pipefail is set, which is not assumed here.
   • git merge-base --is-ancestor proves the commit is reachable from main. Mere existence is not enough: a commit can be present locally because another branch was fetched, and if its version files happen to match it would otherwise pass every remaining check.
   • The version test reads package.json out of the target commit, not the working tree — which would still show the right version while $SHA pointed elsewhere.
   • The awk lifts that version's section out of the commit's CHANGELOG.md for --notes-file. Without it the release body is whatever --notes-from-tag finds in the annotation — here the literal string vX.Y.Z, a poor release note for any version and a misleading one for a release carrying a breaking change. It stops at the next ## [ heading or at the first link-reference definition, because the oldest entry has no heading after it and would otherwise swallow the whole link-reference block. grep -q rather than test -s guards the result: a section empty apart from its blank line still produces a one-byte file, which test -s accepts.
   • --verify-tag makes gh abort rather than invent a tag if the push did not land — the guard against the tip-of-default-branch fallback described above.

   If gh release create fails after the tag is already pushed, do not rerun the whole block; it will stop at git tag, which is correct. Rerun only the final command.

4. The Publish to npm + MCP Registry workflow runs automatically: it npm publishes with provenance, polls the registry until the tarball is available, then pushes the matching server.json to the MCP Registry via mcp-publisher.

The workflow skips npm publish cleanly if the version is already on npm (cutover guard for releases that were partially published manually).

npm authentication

Publishing uses npm Trusted Publishing: the workflow's GitHub OIDC token (id-token: write) is exchanged for a one-shot publish token at runtime. No NPM_TOKEN secret needs to live in the repo.

The binding is configured in the npm web UI (package → Trusted Publishers): provider GitHub Actions, organization lazyants, repository transkribus-mcp-server, workflow publish-registry.yml.

License

FSL-1.1-MIT — see LICENSE for the full terms. Versions 1.x remain MIT-licensed.