# @nicknisi/pi-save-md

Save the most recent assistant response in the current session to a Markdown file in the working directory. It exists because pi has no built-in way to export a single response to a file — the full session transcript lives in pi's session storage, but extracting just the latest answer as a standalone `.md` requires digging through that store. This extension adds one slash command, `/save-md`, that does it in place.

## What it adds

- Slash command: `/save-md <name>`

No tools, keybindings, widgets, overlays, event hooks, or custom message/entry types.

## Usage

```
/save-md notes
/save-md notes.md
/save-md research/api-comparison
```

Behavior:

1. Waits for the agent to be idle (`ctx.waitForIdle()`), so invoking it while a response is streaming waits for the response to finish.
2. Walks the current session branch backwards (`ctx.sessionManager.getBranch()`) to find the latest assistant message.
3. Extracts only `text` content blocks from that message, joining them with blank lines. Non-text blocks (tool calls, thinking, images) are dropped.
4. Appends `.md` if the name doesn't already end in it, resolves the path relative to `ctx.cwd`, and writes the file.
5. Ensures the file ends with a trailing newline.

Examples:

```
/save-md summary        → writes <cwd>/summary.md
/save-md docs/plan      → writes <cwd>/docs/plan.md (docs/ must already exist)
```

Failure modes, all reported via `ctx.ui.notify`:

| Condition                                   | Level   | Message                                              |
| ------------------------------------------- | ------- | ---------------------------------------------------- |
| No assistant message in the current branch  | warning | `No assistant response to save`                      |
| Empty `<name>` argument                     | warning | `Usage: /save-md name`                               |
| Latest assistant message has no text blocks | warning | `The latest assistant response has no Markdown text` |
| Target file already exists                  | error   | `File already exists: <path>`                        |

## Configuration

None. No config files are read, no options exist, and no environment variables are consulted.

## Dependencies

Peer dependencies (both `*`):

- `@earendil-works/pi-coding-agent` — `ExtensionAPI` type. At runtime uses `pi.registerCommand`, `ctx.waitForIdle`, `ctx.sessionManager.getBranch`, `ctx.ui.notify`, and `ctx.cwd`.
- `@earendil-works/pi-ai` — `AssistantMessage` type only.

Runtime dependencies: Node builtins `node:fs/promises` (`writeFile`) and `node:path` (`resolve`). No npm dependencies, no workspace deps.

## Caveats

- **Only text blocks are saved.** Tool calls, tool results, thinking blocks, and any other non-`text` content in the assistant message are silently omitted. If the last assistant turn was purely tool calls with no final text, the command reports there is nothing to save.
- **Current branch only.** `getBranch()` returns the active branch of the session tree; messages on other branches are not considered.
- **No overwrite.** The file is written with flag `wx` (exclusive create). Re-running `/save-md` with the same name fails with an `EEXIST` error rather than overwriting. Delete the file or pick a new name.
- **No directory creation.** Parent directories of the target path must already exist; otherwise `writeFile` throws (the error propagates rather than being notified).
- **Pi internals.** Depends on the session entry shape (`entry.type === "message"`, `entry.message.role`) and on `ctx.sessionManager.getBranch()` / `ctx.ui.notify` APIs, any of which could change across pi versions. The content-block filter is written defensively (structural checks, no casts) to tolerate shape drift in message content.

## Install

```
pi install /Users/nicknisi/Developer/pi-extensions/packages/save-md
```