Why did sign-ups drop?
Quest Find out why sign-ups fell last week using PostHog and a local data export
- Hero
- Claude Code
- Weapon
Claude Sonnet 5.5- Charge
PostHog
DuckDB / MotherDuck MCP
Anthropic Data
Local MCP server that runs DuckDB SQL on in-memory databases, local files, S3 or MotherDuck and lists tables and columns.
How it works
Foe: Riddle Sphinx, a question your data hasn't answered yet.
Foes
- Riddle SphinxHaze Poison Ward Insight Flicker Pinned Enraged
Party · Context
- AlchemistYour agent100/100Haze Poison Ward Insight Flicker Pinned Enraged
The Riddle Sphinx blocks the way.
What really happensIt stands for a question your data hasn't answered yet.
Alchemist: Context 100/100.
The sphinx asks a riddle. A wrong guess costs dearly.
What really happensAn answer guessed from a hunch instead of a query sends the work the wrong way.
Alchemist takes 11. Alchemist: Context 89/100.
A small duck engine hums to life beside the hero.
What really happensThe agent starts mcp-server-motherduck with uvx. The dev setup opens an in-memory DuckDB with write access.
Riddle Sphinx takes 28.
The engine lists every shelf and label.
What really happenslist_databases, list_tables and list_columns show what is attached before any query runs.
Riddle Sphinx takes 13.
The Riddle Sphinx uses Riddle.
Alchemist takes 11. Alchemist: Context 78/100.
A DuckDB query cuts straight to the answer.
What really happensexecute_query runs SQL in the DuckDB dialect and returns JSON, capped at 1024 rows by default.
Riddle Sphinx takes 31.
The duck flies to another pond when asked.
What really happensswitch_database_connection moves to a local file, an S3 database or MotherDuck. It needs --allow-switch-databases.
Riddle Sphinx takes 28. Riddle Sphinx falls.
The Riddle Sphinx falls.
1 / 8
Learn this spell
Claude Code
claude mcp add --scope user duckdb --transport stdio -- uvx mcp-server-motherduck --db-path :memory: --read-write --allow-switch-databasesCodex
codex mcp add duckdb -- uvx mcp-server-motherduck --db-path :memory: --read-write --allow-switch-databasesNotes
Latest release v1.1.0. Needs uv. The install shown is the in-memory dev mode with read-write and database switching. Point --db-path at a .duckdb file without --read-write for read-only. MotherDuck needs motherduck_token. Results cap at 1024 rows and 50,000 characters by default. The README warns that read-only mode still allows local file access, so it is not safe to expose to third parties as is.
Equipped in these loadouts
Combos with this spell
Analyze local files, then check the result
Alchemist · Data analysis- DuckDB / MotherDuck MCP
- Anthropic Data
This spell has no recorded sessions in the curator's logs. Tried it? Send a spell report.