A Catholic MCP server for your AI agent: liturgy, Scripture, and Mass times

General AI models know a lot about the Catholic faith and get the details wrong: a line missing from the Memorare, Ascension Thursday on the wrong day, a Mass time that was never published. Gianna runs an MCP server at https://gianna.chat/mcp that gives any AI agent the checked answer, with its source.

What your agent can look up

The liturgy

• Any day's celebration, rank, colour, saints, and readings in the Ordinary Form, the 1962 calendar, or the Dominican calendar.
• The hours of the Office, in the traditional and Dominican forms.
• Holy days of obligation, including national variations such as England and Wales.

Scripture and prayer

• Exact Bible text with its citation, from public-domain editions.
• Common prayers word for word, in English or Latin.
• Nearly 90 novenas, found by saint, feast, or need.

Church teaching

• Passages from the Catechism, the Code of Canon Law, Vatican II, and papal documents, read from the Holy See's website with the exact URL.
• Reliable Catholic sources for a question.

Churches and the wider Church

• Churches near a place, with Mass and Confession times taken from the parish's own website and the date each was checked.
• Saints, relics, apparitions, and Eucharistic miracles, from curated records that keep their sources.
• Dioceses and their current office holders, and the lineage of bishops: who consecrated whom, back as far as the records go.
• Parish groups to join, and jobs where Catholics want to hire Catholics.

What your agent can do for you

With your permission, the agent can act on your Gianna household:

• start a novena, mark each day prayed, and offer it for an intention;
• add and update prayer intentions;
• add tasks and set reminders;
• ask Gianna to remember something.

Gianna then delivers the reminders and the day's novena prayer on the web, by email, or on Telegram, whether or not the agent is running.

Anything that would share your details with someone else, such as asking to join a parish group, waits for your approval. Gianna emails you and nothing is sent until you approve it.

Built for agents

• One result shape. Every tool returns typed records, sources, and a receipt sentence that is safe to show the user.
• Verified changes. After a change, Gianna reads the records back and reports whether they changed exactly as described.
• Safe retries. Send an idempotency key with a change and a retried call returns the first result instead of acting twice.
• Scoped access. Keys can be read-only, and every change an agent makes is listed in Settings, Developer access, where you can revoke it at once.

The full tool list and result fields are in Gianna for AI agents.

Connect it

Claude (web and desktop): Settings, Connectors, Add custom connector, then enter https://gianna.chat/mcp.

ChatGPT: turn on Developer mode in Settings, Security and login, open Plugins, choose +, and enter https://gianna.chat/mcp.

Codex:

codex mcp add gianna --url https://gianna.chat/mcp
codex mcp login gianna

Claude Code, with an API key from Settings, Developer access:

claude mcp add --transport http gianna https://gianna.chat/mcp \
  --header "Authorization: Bearer $GIANNA_API_KEY"

Cursor, VS Code, Gemini CLI, and any other client using the Streamable HTTP transport connect the same way, with OAuth 2.1 sign-in or a bearer key. An agent with no browser can sign you in with a short code through the OAuth device flow; give it https://gianna.chat/onboard.md.

The Gianna skill

The skill at /skill.md tells an agent when to use these tools and how: quote prayers exactly, cite the source of a Mass time, and check that an action succeeded. Save it as ~/.claude/skills/gianna/SKILL.md for Claude Code or ~/.agents/skills/gianna/SKILL.md for Codex.

Things to ask

"What feast is it on Sunday, and what colour are the vestments?"

"Give me the Apostles' Creed in Latin."

"Is the Ascension a holy day of obligation in England and Wales this year?"

"When is Confession at St Mary's in Cambridge this Saturday?"

"Start the novena to St Joseph and remind me at 7am each day."

What it costs

The Catholic reference tools are free with a Gianna account: the liturgy, Scripture, prayers, Church teaching, churches, saints, relics, lineage, groups, and jobs. Acting on a household needs a plan. The Terms do not allow reselling the data or copying it in bulk.

Price and the early-bird offer

The early-bird offer gives half price for your first year. Standard is $5 a month or $40 a year, normally $10 or $80. Pro, with voice notes and photo reading, is $10 a month or $80 a year, normally $20 or $160. One subscription covers the household, the first seven days are free, and nothing is charged during the trial. Prices checked on 17 October 2026; see gianna.chat for current terms, or start the free trial.

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