bible-tools

A read-only Model Context Protocol server over STEPBible open data: the Hebrew Old Testament and the Greek New Testament tagged with Strong's numbers and morphology, Hebrew and Greek lexicons, explanations of the morphology codes, and a database of proper names. Alongside them it serves the verse text of five public-domain or freely licensed translations (KJV, Darby, Elberfelder 1905, Ohienko, Russian Synodal) in KJV numbering. The server announces itself as bible-tools.

It is built for Bible translators, students of the original languages and people building agents that need grounded source-language data instead of guesses.

• Read-only and stateless: no writes, no user accounts, no model calls inside the server.

• Local stdio transport.

• Data is loaded into a local SQLite database built from a pinned STEPBible revision and the theWord translation modules vendored in data/theword/ (checked against the sha256 sums in data/theword/MANIFEST.json).

Requirements

• Node.js >= 24.12

• pnpm 12

Related MCP server: bible-translation-mcp

Setup

pnpm install
pnpm data:fetch   # downloads the STEPBible files at the pinned revision into data/raw/ (about 115 MB)
pnpm data:build   # builds data/bible.sqlite (about 127 MB, takes under a minute)

The server reads data/bible.sqlite by default; set BIBLE_DB to use another file. If the file is missing the server prints one line telling you which commands to run and exits.

Tools

All tools are read-only and take English book names or OSIS ids (Ruth, 1Sam, John, 1Cor). Verse numbers follow English (NRSV) versification by default; pass "versification": "heb" for the Hebrew (Leningrad) numbering of the Old Testament. The New Testament has only English numbering.

Example calls (tool arguments):

{ "name": "get_original", "arguments": { "ref": "Ruth 1:1" } }
{ "name": "get_original", "arguments": { "ref": "John 1:1", "morphology": true } }
{ "name": "get_translation", "arguments": { "ref": "Num 13:1-3", "version": "rst" } }
{ "name": "lookup_strong", "arguments": { "strong": "H7704G" } }
{ "name": "explain_morphology", "arguments": { "code": "V-AAI-3S" } }
{ "name": "get_names", "arguments": { "ref": "Ruth 1:2", "versification": "heb" } }

Errors come back as tool results with isError set and a hint on how to fix the call.

Resources

Hosts can attach data as context through three resource templates (plain text, the same output as the matching tool). They are not listed, since there is nothing sensible to enumerate.

ref is URL-encoded; Ruth.1.1 is accepted too. Invalid input is a JSON-RPC error with the same hint the tools give.

Prompts

Use with Claude Desktop or Claude Code

Use absolute paths for node and for src/stdio.ts; the --disable-warning flag silences the Node SQLite experimental warning.

{
  "mcpServers": {
    "bible": {
      "command": "/absolute/path/to/node",
      "args": [
        "--disable-warning=ExperimentalWarning",
        "/absolute/path/to/bible-tools/src/stdio.ts"
      ],
      "env": { "BIBLE_DB": "/absolute/path/to/bible-tools/data/bible.sqlite" }
    }
  }
}

For Claude Code:

claude mcp add bible -- /absolute/path/to/node --disable-warning=ExperimentalWarning /absolute/path/to/bible-tools/src/stdio.ts

env is optional when the database is at the default location. Find the node path with which node.

HTTP

pnpm start:http

Serves the same tools, resources and prompts over stateless Streamable HTTP: every request gets a fresh server instance and no session is kept.

GET and DELETE on /mcp answer 405, as there are no sessions to open or close.

Requests to /mcp with any other Host or Origin answer 403, so a public deployment must set ALLOWED_HOSTS to its hostname; /health keeps answering 200 either way. Requests without an Origin are accepted, as non-browser clients do not send one.

The rate limit is global, not per client IP: behind a reverse proxy the socket address is the proxy's, and every claude.ai connector calls from Anthropic's addresses anyway. Forwarded headers (X-Forwarded-For, CF-Connecting-IP) are not trusted.

Docker

docker build -t bible-tools .
docker run --rm -p 3000:3000 bible-tools
curl http://localhost:3000/health

The build downloads the STEPBible files at the pinned revision (about 115 MB), reads the translation modules from data/theword/ and builds the database inside the image, so it needs network access and takes a few minutes; the image is about 500 MB and holds no raw data files. The container runs as the unprivileged node user, listens on PORT (default 3000) and has a health check on /health. docker stop ends it cleanly with exit code 0.

With the default ALLOWED_HOSTS only localhost is accepted in the Host header. Behind a domain, pass the hostname (comma-separated for several):

docker run --rm -p 3000:3000 -e ALLOWED_HOSTS=mcp.example.com bible-tools

Deploy on Render

render.yaml is a blueprint for a Docker web service on Render's free tier.

1. Push the repository to GitHub, GitLab or Bitbucket.

2. In the Render dashboard choose New > Blueprint and select the repository. Render reads render.yaml, builds the image and starts the service. A push to main deploys once CI has passed (autoDeployTrigger: checksPass).

3. If the service name bible-tools was already taken, Render appends a suffix. Then set ALLOWED_HOSTS to the real hostname of the service (<service>.onrender.com) in the service's environment settings; requests with another Host get 403. ALLOWED_ORIGINS is set to claude.ai: a request that carries an Origin header is accepted only when the header's hostname is in that list, and requests without an Origin header are not affected.

Render sets PORT itself and uses /health for its health check.

Free-tier services sleep after 15 minutes without traffic, and the first request after that waits about a minute for a cold start. To avoid it, ping https://<service>.onrender.com/health every few minutes from an uptime monitor or a scheduled job. All clients share one rate limit of RATE_LIMIT requests per minute (600 by default).

Use as a Claude connector

Once the service is up, add it to Claude as a custom connector: in Claude's settings open Connectors, choose Add custom connector, enter a name and the URL

https://<service>.onrender.com/mcp

and choose no sign-in, as the server needs no account or key. The same URL works for claude mcp add --transport http bible https://<service>.onrender.com/mcp in Claude Code.

MCP Inspector

pnpm inspect

This starts the MCP Inspector against the stdio server so you can list the tools and call them from a browser UI.

Development

pnpm check              # type check
pnpm lint               # oxlint, type-aware
pnpm fmt                # format (pnpm fmt:check only verifies)
pnpm test               # unit, database, golden and end-to-end tests; no database file needed
pnpm test:realdb        # smoke tests against data/bible.sqlite; skipped when it is absent
pnpm test:mutation      # Stryker mutation testing of src/ (fails below a score of 80)
pnpm fixtures           # regenerate test/fixtures/raw/ from data/raw/ and test/fixtures/theword/ from data/theword/
pnpm inspect            # open the MCP Inspector

Source code is TypeScript run directly by Node (type stripping), so there is no build step.

Alternatives

Other MCP servers cover similar ground. This comparison is based on each project's README and repository page as of 2026-11-07; the source code was not read, so claims about behaviour are the projects' own.

What this server offers instead: a small, read-only set of seven tools over STEPBible data and five public-domain or freely licensed translations, with every output bounded to about 2,000 characters and a hint for the next call; both Testaments with Strong's numbers, morphology and an explanation of every morphology code; proper names with their kinds; MIT code and openly licensed data that can be used and redeployed with attribution; and a single Docker image with a health check and a Render blueprint. It has no text search, no cross-references, no syntax trees and no textual variants.

Data and attribution

Lexical and textual data comes from STEPBible.org, Tyndale House, Cambridge (STEPBible-Data), licensed under CC BY 4.0. Source revision 5de0a47f35f0fc13dfe1430d104e5db8a4285f9c, reformatted into SQLite. The files used are TAHOT (Hebrew Old Testament), TAGNT (Greek New Testament), TBESH and TBESG (brief Hebrew and Greek lexicons), TIPNR (proper names) and TEHMC and TEGMC (morphology codes). See DATA-LICENSE.md.

The Greek text is an amalgam of several editions; one reading per verse is stored, the Nestlé-Aland text, or the traditional text for the few verses Nestlé-Aland omits. See docs/adr/0005-greek-base-text.md.

Translations come from theWord Bible modules, vendored in data/theword/:

License

Code: MIT. Data: STEPBible CC BY 4.0; the translations as listed above (the database contains the Ohienko text under CC BY-SA 4.0). See DATA-LICENSE.md.