feat(cursor): add bub-cursor package

README.md

@@ -16,6 +16,7 @@ Below is the list of packages currently included in this repository.
 | Package                                                                              | Bub Plugin Entry Point | Description                                                                                                                                          |
 | ------------------------------------------------------------------------------------ | ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
 | [`packages/bub-codex`](./packages/bub-codex/README.md)                               | `codex`                | Provides a `run_model` hook that delegates model execution to the Codex CLI.                                                                         |
+| [`packages/bub-cursor`](./packages/bub-cursor/README.md)                             | `cursor`               | Provides a `run_model` hook that delegates model execution to the Cursor CLI, plus `bub login cursor`.                                               |
 | [`packages/bub-tg-feed`](./packages/bub-tg-feed/README.md)                           | `tg-feed`              | Provides an AMQP-based channel adapter for Telegram feed messages.                                                                                   |
 | [`packages/bub-schedule`](./packages/bub-schedule/README.md)                         | `schedule`             | Provides scheduling channel/tools backed by APScheduler with a JSON job store.                                                                       |
 | [`packages/bub-tapestore-sqlalchemy`](./packages/bub-tapestore-sqlalchemy/README.md) | `tapestore-sqlalchemy` | Provides a SQLAlchemy-backed tape store for Bub conversation history.                                                                                |

packages/bub-cursor/README.md

@@ -0,0 +1,94 @@
+# bub-cursor
+
+Cursor CLI-backed model plugin for `bub`.
+
+## What It Provides
+
+- 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`
+
+## Installation
+
+```bash
+uv pip install "git+https://github.com/bubbuild/bub-contrib.git#subdirectory=packages/bub-cursor"
+```
+
+You can also install it with Bub:
+
+```bash
+bub install bub-cursor@main
+```
+
+## Prerequisites
+
+- 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:
+
+```bash
+cursor-agent --version
+# or
+agent --version
+```
+
+Browser login is available through Cursor CLI:
+
+```bash
+cursor-agent login
+# or
+agent login
+```
+
+or through Bub:
+
+```bash
+bub login cursor
+```
+
+CLI path resolution uses this order: `BUB_CURSOR_CLI_PATH`, `cursor-agent`,
+then `agent`.
+
+## Configuration
+
+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\`.`
+
+## Runtime Behavior
+
+- 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.
+
+## Skill Integration
+
+- 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.
+
+## Notes
+
+Cursor CLI non-interactive mode can modify files in the selected workspace.

packages/bub-cursor/pyproject.toml

@@ -0,0 +1,19 @@
+[project]
+name = "bub-cursor"
+version = "0.1.0"
+description = "Cursor-backed run_model plugin for Bub"
+readme = "README.md"
+authors = [
+    { name = "tssujt" }
+]
+requires-python = ">=3.12"
+dependencies = [
+    "pydantic-settings>=2.13.1",
+]
+
+[project.entry-points.bub]
+cursor = "bub_cursor.plugin"
+
+[build-system]
+requires = ["uv_build>=0.10.4,<0.11.0"]
+build-backend = "uv_build"

packages/bub-cursor/src/bub_cursor/auth.py

@@ -0,0 +1,80 @@
+from __future__ import annotations
+
+import asyncio
+import os
+import shutil
+
+CURSOR_API_KEY_ENV = "CURSOR_API_KEY"
+CURSOR_CLI_CANDIDATES = ("cursor-agent", "agent")
+CURSOR_AUTH_ERROR_MESSAGE = (
+    "No Cursor authentication found. Run `bub login cursor` first or set "
+    "`CURSOR_API_KEY`."
+)
+
+
+class CursorLoginError(RuntimeError):
+    """Raised when Cursor CLI login cannot be started or completed."""
+
+
+def resolve_cursor_cli_path(cli_path: str | None = None) -> str:
+    if cli_path and cli_path.strip():
+        return cli_path
+    for candidate in CURSOR_CLI_CANDIDATES:
+        if resolved := shutil.which(candidate):
+            return resolved
+    return CURSOR_CLI_CANDIDATES[0]
+
+
+async def run_cursor_login(cli_path: str) -> int:
+    try:
+        process = await asyncio.create_subprocess_exec(cli_path, "login")
+    except FileNotFoundError as exc:
+        raise CursorLoginError(f"Cursor CLI not found: {cli_path}") from exc
+    return await process.wait()
+
+
+def has_cursor_api_key() -> bool:
+    return bool(os.getenv(CURSOR_API_KEY_ENV, "").strip())
+
+
+async def has_cursor_cli_login(cli_path: str, *, timeout_seconds: float = 10.0) -> bool:
+    try:
+        process = await asyncio.create_subprocess_exec(
+            cli_path,
+            "status",
+            stdout=asyncio.subprocess.PIPE,
+            stderr=asyncio.subprocess.PIPE,
+        )
+    except FileNotFoundError as exc:
+        raise CursorLoginError(f"Cursor CLI not found: {cli_path}") from exc
+    try:
+        stdout, stderr = await asyncio.wait_for(
+            process.communicate(),
+            timeout=timeout_seconds,
+        )
+    except TimeoutError:
+        process.kill()
+        await process.communicate()
+        return False
+    output = f"{stdout.decode(errors='ignore')}\n{stderr.decode(errors='ignore')}"
+    return process.returncode == 0 and "logged in as" in output.lower()
+
+
+async def ensure_cursor_authenticated(cli_path: str) -> None:
+    if has_cursor_api_key():
+        return
+    if await has_cursor_cli_login(cli_path):
+        return
+    raise RuntimeError(CURSOR_AUTH_ERROR_MESSAGE)
+
+
+__all__ = [
+    "CURSOR_AUTH_ERROR_MESSAGE",
+    "CURSOR_CLI_CANDIDATES",
+    "CursorLoginError",
+    "ensure_cursor_authenticated",
+    "has_cursor_api_key",
+    "has_cursor_cli_login",
+    "resolve_cursor_cli_path",
+    "run_cursor_login",
+]