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C3DB

Query the competition-climbing warehouse from your browser, terminal, or your own AI.

Query in your browser

A browser workspace for SQL and plain-English queries. Nothing to install.

Open the web console →

1. Run SQL

Install the client, sign in once, then send read-only SQL. You get a table back.

pip install c3db
c3db login
c3db query "SELECT * FROM event_standings WHERE final_rank = 1 LIMIT 5"
Create or manage keys in your browser →

2. Use it in ChatGPT, Gemini, or Claude

Nothing to install and no key to copy. You add one address to the app, sign in to C3DB when it asks, then ask your questions in plain language. The app reads the database structure and writes the SQL for you.

The address to paste:

https://c3db-mcp-rt24zk2pna-uc.a.run.app/mcp

You need a free C3DB account. A sign-in page opens partway through the steps below. Create the account there if you do not have one.

Claude, at claude.ai

  1. Open claude.ai and sign in.
  2. Click your name at the bottom left, then Settings, then Connectors.
  3. Click Add custom connector.
  4. Paste the address above into the URL field, then click Add.
  5. Click Connect next to C3DB, sign in to C3DB, then click Allow.
  6. In a chat, click the + button, open Connectors, and switch C3DB on.

On Team and Enterprise plans an owner adds the connector under Admin settings first, then everyone else clicks Connect.

ChatGPT, at chatgpt.com

  1. Open chatgpt.com and sign in.
  2. Open Settings, then Connectors, then Advanced, and turn on Developer mode.
  3. Go back to Connectors and click Create.
  4. Name it C3DB, paste the address above as the server URL, then click Create.
  5. Sign in to C3DB, then click Allow.
  6. In a new chat, click +, then More, then Developer mode, and switch C3DB on.

Developer mode needs a paid plan (Pro, Business, Enterprise, or Edu). You have to switch the connector on in every new chat.

Gemini, at gemini.google.com

  1. Open gemini.google.com and sign in with a personal Google account.
  2. At the bottom, open Settings & help, then Connected Apps. If it is not there, open Personal Intelligence first.
  3. Under Custom apps for Spark, click Add a custom app.
  4. Paste the address above, then click Next.
  5. Sign in to C3DB, then click Allow.
  6. When you write a prompt, type @ and pick C3DB so Gemini uses it.

Google limits this to Gemini Spark users who are 18 or over, in the US, on a personal account, with Keep Activity turned on.

3. Use it in a coding agent

One command registers the warehouse in Claude Code or Cursor. Your agent reads the schema and writes the SQL itself, so no model key is needed. Install the client first, as in step 1.

c3db connect claude
c3db connect cursor

Claude Code and Cursor supported. Codex coming soon.

4. If none of those work: c3db ask

Your own model writes the SQL and C3DB runs it. Claude uses your `ant auth login` sign-in; for OpenAI, DeepSeek, or GLM, set a provider key or run `c3db model set <provider>`.

pip install "c3db[ask]"
c3db ask "who has the most World Cup golds in lead?"

🔒 Your model API key stays on your machine (an environment variable or ~/.config/c3db). It is never sent to C3DB.

Python SDK

Client().query() returns a pandas DataFrame; Client().ask() lets your own model write the SQL.

from c3db import Client

df = Client().query("SELECT athlete_name, count(*) AS golds "
                    "FROM event_standings WHERE final_rank = 1 "
                    "GROUP BY 1 ORDER BY 2 DESC")

# or let your own model write the SQL:
df = Client().ask("who has the most World Cup golds in lead?")

Commands

CommandWhat it does
c3db loginVerify and store your C3DB data key.
c3db query "<sql>"Run a read-only SQL query (-f file / stdin; --format table|csv|json).
c3db ask "<question>"Ask in plain English; your own model writes the SQL. Needs pip install "c3db[ask]".
c3db connect claudeRegister the hosted MCP into Claude Code or Cursor.
c3db schemaPrint the query conventions and authoritative BigQuery DDL.