Cursor CLI-backed model plugin for bub.

• Bub plugin entry point: cursor
• A run_model hook implementation that invokes the Cursor CLI
• bub login cursor, which delegates to Cursor CLI login
• Session continuation via <cursor-cli> --resume=<session_id>
• JSON output parsing from <cursor-cli> -p ... --output-format json
• Optional temporary skill wiring from installed Bub skills into workspace .agents/skills

uv pip install "git+https://github.com/bubbuild/bub-contrib.git#subdirectory=packages/bub-cursor"

You can also install it with Bub:

bub install bub-cursor@main

• Cursor CLI must be installed and available in PATH.
• Cursor CLI must have authentication available through either saved browser login or CURSOR_API_KEY.

Depending on how Cursor CLI was installed, the executable may be named cursor-agent or agent. Homebrew installs cursor-agent; the curl installer usually installs agent.

Verify the CLI with whichever command exists:

cursor-agent --version
# or
agent --version

Browser login is available through Cursor CLI:

cursor-agent login
# or
agent login

or through Bub:

bub login cursor

CLI path resolution uses this order: BUB_CURSOR_CLI_PATH, cursor-agent, then agent.

The plugin reads environment variables with prefix BUB_CURSOR_:

• BUB_CURSOR_MODEL: optional model name passed as --model <value>.
• BUB_CURSOR_CLI_PATH: Cursor CLI executable path. When unset, the plugin tries cursor-agent, then agent.
• BUB_CURSOR_TIMEOUT_SECONDS: subprocess timeout. Defaults to 300.

Cursor CLI also reads its own authentication environment variables, such as CURSOR_API_KEY, directly. When neither saved Cursor login nor CURSOR_API_KEY is available, the plugin raises No Cursor authentication found. Run \bub login cursor` first or set `CURSOR_API_KEY`.`

• Workspace resolution:
  • Uses state["_runtime_workspace"] when present
  • Falls back to current working directory
• Command shape:
  • <cursor-cli> -p <prompt> --output-format json
  • <cursor-cli> --resume=<session_id> -p <prompt> --output-format json
• The plugin stores Cursor session IDs in <workspace>/.bub-cursor-threads.json.
• Cursor CLI stdout is parsed as JSON; the result field is returned as model output.

• During invocation, the plugin scans skills for directories containing SKILL.md.
• It creates symlinks under <workspace>/.agents/skills/<skill_name>.
• Symlinks created by this plugin invocation are removed after the run.

Cursor CLI non-interactive mode can modify files in the selected workspace.