Use python-vibe in Cursor

Cursor talks to python-vibe as a local child process. Your code stays on this machine. You do not open a port and you do not point chat at 127.0.0.1.

This page is a live walkthrough on demo/orders. 5 September 2026. brief needs no model. ask calls llama3.1:8b. The NameError repair is a harness demo — no model.

Recorded with asciinema. The GIF is what chat and Tasks: Run Task run after python-vibe editors cursor --allow-writes, not a screenshot of the editor window. Replay:

asciinema play docs/media/cursor-demo.cast

Re-record it (needs Ollama llama3.1:8b):

PYTHONPATH=src python scripts/measure/record_cursor.py

One-time setup

From a clone (same installer as Start):

python3 scripts/run/install.py
source .venv/bin/activate
ollama pull llama3.1:8b
python-vibe editors cursor --allow-writes

macOS often has no pip on PATH. The installer creates .venv and runs python -m pip for you. Activate that venv in every new terminal or python-vibe will still be missing.

Without installing, from the checkout:

PYTHONPATH=src python3 -m harness editors cursor --allow-writes

--project defaults to the folder you are in. The command writes two files:

${workspaceFolder} is filled by Cursor, so the MCP file has no personal path. You can commit it. Anyone who clones the repo and reloads the window gets the same tools. The task file names the interpreter that ran editors cursor. Do not commit that path.

Then in Cursor

1. Command Palette → Developer: Reload Window
2. Open Customize → MCP and enable python-vibe
3. In chat, say what you want. Name the tool if you like:
   • “ask python-vibe what compute_total returns”
   • “run python-vibe: write tests for apply_discount”
   • “run python-vibe: find the NameError and fix it”

ask never writes. run writes only when you passed --allow-writes.

A large tree: add a scope (“stay in src/”). The write limit already refuses to load the whole tree.

The same jobs are also Tasks: Run Task → python-vibe: brief / ask / run. Do not type python-vibe: ask in the shell. The colon is the task label. In a terminal the commands are:

source .venv/bin/activate
cd demo/orders
python-vibe brief
python-vibe ask  "what does compute_total return?"
python-vibe run  "find the NameError and fix it"

If the shell says command not found: python-vibe, the venv is not active. Activate it in every new terminal.

Live: this folder, those tools

Open demo/orders (or this repo and stay in that folder). Reload, enable the server, then ask in chat. editors, brief, ask, and the NameError run below are the GIF.

python-vibe editors cursor --allow-writes

Writes .cursor/mcp.json and .vscode/tasks.json. No model.

$ python-vibe editors cursor --allow-writes
/private/tmp/cursor/.cursor/mcp.json
/private/tmp/cursor/.vscode/tasks.json

python-vibe is set up for this folder (read-write).
1. ollama pull llama3.1:8b
2. Command Palette → Developer: Reload Window
3. Open Customize → MCP → enable python-vibe
4. In chat: ask python-vibe what compute_total returns
   or Tasks: Run Task → python-vibe: ask
Do not point Override OpenAI Base URL at 127.0.0.1. That request often
leaves this machine.

python-vibe brief

No prompt. Instant. No model.

$ python-vibe brief

10 Python and Markdown files, 2.9 KB in total.
Small enough that python-vibe can read all of it, so you can ask about any part.

Files:
  README.md  685 B
  src/__init__.py  68 B
  src/orders.py  467 B
  src/orders_controller.py  568 B
  src/orders_service.py  285 B
  src/render.py  193 B
  src/report.py  155 B
  src/util.py  67 B
  tests/__init__.py  0 B
  tests/test_orders.py  511 B

python-vibe has 24 skills it can apply. It picks them from the wording of
your task; you do not choose them.

python-vibe ask

Type: what does compute_total return?

Needs the 8B. About fifteen seconds on this run. The first draft was only int. The helper sent that back. The second draft named what the function computes.

$ python-vibe ask "what does compute_total return?"
ollama:llama3.1:8b  project /private/tmp/cursor  mode small

--- step 1 ---
Action: done
Summary: "int"

too thin. Action: done Summary: quote int and say in a sentence what it
computes, from the code you read.

--- step 2 ---
Action: done
Summary: The `compute_total` function computes the sum of the line
prices of one order, returning an integer value.

The `compute_total` function computes the sum of the line prices of one
order, returning an integer value.

ask never writes a file.

python-vibe run

Type: find the NameError and fix it

The planted typo is subtotl next to subtotal =. One candidate. No model. About a tenth of a second.

$ python-vibe run "find the NameError and fix it"

bound unique NameError typo (subtotl → subtotal) in src/orders.py. Tests passed.

run writes only with --allow-writes on the server, or when you use the task (a real python-vibe run in the project folder). It keeps a .bak of anything it edits.

Every workspace on this laptop

python-vibe editors cursor --global --allow-writes

Merges python-vibe into ~/.cursor/mcp.json. Other servers stay. Each window limits changes to the folder you have open.

Clone this repo

This repository already ships .cursor/mcp.json. Open the folder in Cursor, reload, enable the server. No extra command.

What not to do

Do not set Models → Override OpenAI Base URL to http://127.0.0.1:8081/v1 or :8090. Many Cursor builds send that request from a remote backend, which cannot see your loopback. A public HTTPS tunnel would let the internet reach it.

Use MCP or Run Task. Both stay on this machine.

Related: In your editor · VS Code · local editor · IDE plugins · Live demo (shell).