extending-pi

Files (1)

• SKILL.md

SKILL.md (first lines)

# Extending Pi (Pi for Excel)

Use this skill when the user asks to extend Pi, add capabilities, or integrate an external API/tool.

## Default behavior (non-negotiable)

- Prefer solutions the assistant can set up and run itself.
- Never ask users to paste API keys/tokens/passwords in chat.
- Never create `/set-key ...` style commands that take secrets from the prompt input.
- Prefer first-class connection setup UX (`/tools` → Connections) for secret entry.
- For API-backed plugin implementation/testing, proactively recommend local bridge setup:
  - **Preferred:** Python bridge (best for API prototyping, payload transforms, quick debugging scripts).
  - **Fallback:** tmux bridge (assistant can still run `curl`, Node scripts, and CLI checks).
  - If neither is available, still scaffold the extension, but explicitly note reduced verification and offer setup help.

When recommending bridge setup, read the relevant setup skill before giving commands:
- `python-bridge`
- `tmux-bridge`

## 1) Choose the right extension surface

| Goal | Build | Why |
|---|---|---|
| Teach Pi a workflow, process, or decision rubric | **Skill** | Lowest maintenance; mostly instruction logic |
| Add runtime behavior (slash command, tool, widget, event handling, storage/http) | **Extension plugin** | Requires executable code |
| Add secure credential/config setup for extension tools | **Extension connection** | First-class setup/status/preflight/error guidance |
| Save one-off user/workbook preferences | **instructions** tool | Not an extension |

Heuristic: if instructions + existing tools are enough, build a **skill** first.

---

## 2) Skill authoring (adapted from `skill-creator`, flat profile)

For this repo, default to **flat skills**: one `skills/<name>/SKILL.md` file.
Only add extra folders if clearly needed.

### Core principles

- **Conciseness:** only include domain-specific guidance the model cannot infer reliably.
- **Activation quality:** trigger matching comes from frontmatter `description`; make it precise.
- **Context over directives:** explain why an approach works, not just rigid commands.
- **Progressive disclosure (lightweight):** keep SKILL.md focused; avoid dumping long reference text.

### Required format and naming

- Required frontmatter: `name`, `description`
- Directory name must equal `name`
- Name rules:
  - 1-64 chars
  - lowercase letters, digits, hyphens
  - no leading/trailing/consecutive hyphens

### Workflow

1. Capture 2-4 concrete user prompts the skill should handle.
2. Create `skills/<name>/SKILL.md`.
3. Write frontmatter:

```yaml
---
name: my-skill
description: What it does + when to use it.
compatibility: Optional constraints.
---
```

4. Write body with:
   - purpose and boundaries
   - mapping to relevant tools/integrations
   - step-by-step workflow
   - guardrails/pitfalls
5. Install/update via `skills` tool (`install`/`uninstall`) when available; otherwise use `/extensions` → Skills.
6. Validate with `skills` tool:
   - `action="list"`
   - `action="read"` for the new skill.

---

## 3) Extension plugin workflow

Use when the user needs new executable behavior.

1. Build a single-file ES module with `activate(api)`.
2. Register only required surfaces (`registerCommand`, `registerTool`, widget, etc.).
3. Keep capabilities least-privilege.
4. Install from chat using `extensions_manager` (`install_code`, `set_enabled`, `reload`, `uninstall`).
5. Validate by invoking the new command/tool end-to-end.

Minimal skeleton:

```ts
export function activate(api) {
  api.registerCommand("hello_ext", {
    description: "Example command",
    handler: () => api.toast("Hello from extension"),
  });

  return () => {
    api.widget.dismiss();
    api.overlay.dismiss();
  };
}
```

---

## 4) API keys/secrets: secure-by-default pattern

### Tier 1 (default): host-injected auth via `http.fetch(..., { connection })`

For API-backed extension tools:

1. Register a connection in `activate(api)`.
2. Add `httpAuth` on the connection definition with a strict `allowedHosts` list.
3. Mark tools with `requiresConnection`.
4. Direct user to `/tools` → Connections for secret entry.
5. Call `api.http.fetch(url, { connection: "<id>" })`.

From tmustier/pi-for-excel, MIT.

More from tmustier/pi-for-excel