feat: add native Windows support for pi-memory

CONTRIBUTING.md

@@ -37,7 +37,7 @@ npm run test:smoke
 ## PR checklist
 
 - [ ] No changes to unrelated files
-- [ ] Native build still succeeds (`-Wall -Wextra -Wpedantic`)
+- [ ] Native build still succeeds (`-Wall -Wextra -Wpedantic` on Unix, supported Windows compiler path still works)
 - [ ] `npm run test:smoke` passes
 - [ ] Docs updated
 - [ ] Backward compatibility considered

README.md

@@ -6,7 +6,7 @@
 Durable memory for Pi agents, built for **low-overhead reliability**:
 - **C core** (`native/pi-memory.c`) for speed + minimal runtime surface
 - **TypeScript extension** (`extensions/pi-memory-compact.ts`) for Pi lifecycle automation
-- **SQLite DB** (`~/.pi/memory/memory.db`) for single-file durability and simple ops
+- **SQLite DB** (`~/.pi/memory/memory.db` on Unix, `%USERPROFILE%\\.pi\\memory\\memory.db` on Windows) for single-file durability and simple ops
 
 Repository: https://github.com/SiliconState/Pi-Memory
 
@@ -18,7 +18,7 @@ Pi-Memory is intentionally small:
 - no server process
 - no external DB
 - no runtime framework dependency for core memory engine
-- one local DB: `~/.pi/memory/memory.db`
+- one local DB in your user `.pi/memory` directory
 
 That keeps startup fast, failure modes simple, and behavior predictable.
 
@@ -30,14 +30,14 @@ Pi-Memory is designed as a layered system where each layer has a different job:
 
 | Layer | Responsibility | Location |
 |---|---|---|
-| **1. Core memory engine (C + SQLite)** | Stores structured memory: decisions, findings, lessons, entities, sessions, project state | `~/.pi/memory/pi-memory` + `~/.pi/memory/memory.db` |
+| **1. Core memory engine (C + SQLite)** | Stores structured memory: decisions, findings, lessons, entities, sessions, project state | user `.pi/memory` dir (`pi-memory`/`pi-memory.exe` + `memory.db`) |
 | **2. Pi lifecycle extension (TypeScript)** | Hooks into compaction/session events, syncs memory, ingests sessions, resumes intent | `extensions/pi-memory-compact.ts` (installed by Pi package) |
 | **3. Project memory files (`MEMORY.md`)** | Human-readable, per-project snapshot used as context bridge across sessions | project root `MEMORY.md` with sync markers |
 
 Check current DB coverage at any time:
 
 ```bash
-~/.pi/memory/pi-memory projects
+pi-memory projects
 ```
 
 ---
@@ -81,7 +81,7 @@ This installs all Pi components declared in `package.json`:
 - prompts (`prompts/*.md`)
 - native C binary compile via postinstall
 
-### Alternative one-liner installer (curl)
+### Alternative one-liner installer (Unix only)
 
 ```bash
 curl -fsSL https://raw.githubusercontent.com/SiliconState/Pi-Memory/main/scripts/install.sh | bash
@@ -90,20 +90,23 @@ curl -fsSL https://raw.githubusercontent.com/SiliconState/Pi-Memory/main/scripts
 Then verify:
 
 ```bash
-~/.pi/memory/pi-memory --version
+pi-memory --version
 ```
 
-> SQLite is bundled — the only build prerequisite is a C compiler (`cc`/`gcc`/`clang`).
-> If native compile is skipped during install, rerun the curl installer or follow manual compile troubleshooting in `docs/INSTALL.md`.
+> SQLite is bundled — the only build prerequisite is a C compiler.
+> - Unix: `cc` / `gcc` / `clang`
+> - Windows: `clang`, `gcc`, or Visual Studio `cl`
 >
-> npm/bun publish is planned but not currently live. For now, use the git install (or curl wrapper) above.
+> If native compile is skipped during install, follow the manual compile troubleshooting in `docs/INSTALL.md`.
+>
+> npm/bun publish is planned but not currently live. For now, use the git install above.
 
 ---
 
 ## Quick Start
 
 ```bash
-BIN="${PI_MEMORY_BIN:-$HOME/.pi/memory/pi-memory}"
+BIN="${PI_MEMORY_BIN:-pi-memory}"
 
 # initialize MEMORY.md markers
 "$BIN" init
@@ -140,8 +143,8 @@ Inside Pi, you can manually tune compaction behavior without changing code:
 If you want this change recorded in project memory for teammates/future sessions:
 
 ```bash
-~/.pi/memory/pi-memory state <project> --summary "Compaction threshold set to 75%"
-~/.pi/memory/pi-memory sync MEMORY.md --project <project> --limit 15
+pi-memory state <project> --summary "Compaction threshold set to 75%"
+pi-memory sync MEMORY.md --project <project> --limit 15
 ```
 
 ---

bin/pi-memory.js

@@ -9,7 +9,8 @@ const __dirname = path.dirname(fileURLToPath(import.meta.url));
 const root = path.resolve(__dirname, "..");
 const setupScript = path.join(root, "scripts", "setup.mjs");
 
-const binary = process.env.PI_MEMORY_BIN?.trim() || path.join(os.homedir(), ".pi", "memory", "pi-memory");
+const defaultBinary = os.platform() === "win32" ? "pi-memory.exe" : "pi-memory";
+const binary = process.env.PI_MEMORY_BIN?.trim() || path.join(os.homedir(), ".pi", "memory", defaultBinary);
 
 if (!existsSync(binary)) {
   const setup = spawnSync(process.execPath, [setupScript], { stdio: "inherit" });

docs/AGENT-USAGE.md

@@ -2,7 +2,9 @@
 
 This guide is for agent authors/operators using Pi-Memory in Pi workflows.
 
-If `pi-memory` is not on PATH in your environment, call it explicitly as `~/.pi/memory/pi-memory`.
+If `pi-memory` is not on PATH in your environment, call the installed binary directly:
+- macOS / Linux: `~/.pi/memory/pi-memory`
+- Windows: `%USERPROFILE%\\.pi\\memory\\pi-memory.exe`
 
 ## Core operating rules
 

docs/ARCHITECTURE.md

@@ -15,7 +15,8 @@ The C binary is the source of truth for persistence.
 SQLite database:
 
 ```text
-~/.pi/memory/memory.db
+~/.pi/memory/memory.db                    # macOS / Linux
+%USERPROFILE%\\.pi\\memory\\memory.db      # Windows
 ```
 
 Primary tables:
@@ -69,7 +70,7 @@ The extension automates operational memory hygiene around compaction and shutdow
 
 The packaged extension resolves pi-memory in this order:
 1. `PI_MEMORY_BIN` env var
-2. `~/.pi/memory/pi-memory`
+2. default binary in the user `.pi/memory` dir (`pi-memory` on Unix, `pi-memory.exe` on Windows)
 3. fallback command `pi-memory` in PATH
 
 ## MEMORY.md bridge layer

docs/INSTALL.md

@@ -3,95 +3,150 @@
 ## Platform support
 
 - **macOS** and **Linux** are supported.
-- **Windows** is not currently supported (no native build target).
+- **Windows** is supported with a native Windows C compiler (`clang`, `gcc`, or `cl`).
 
 ## Prerequisites
 
 - Pi installed (`pi` CLI)
-- C compiler (`cc`/`clang`/`gcc`)
+- C compiler
+  - macOS/Linux: `cc` / `clang` / `gcc`
+  - Windows: `clang`, `gcc`, or Visual Studio `cl`
 
-> SQLite is bundled (amalgamation compiled directly into the binary). No system `libsqlite3-dev` or `sqlite3.h` needed.
+> SQLite is bundled (amalgamation compiled directly into the binary). No system `libsqlite3-dev`, `sqlite3.h`, or external database server is required.
 
 ## Option A (recommended): single Pi command
 
 ```bash
 pi install git:github.com/SiliconState/Pi-Memory
 ```
 
-This installs package resources declared in `package.json` (`pi.extensions`, `pi.skills`, `pi.prompts`) and runs native build postinstall.
+This installs package resources declared in `package.json` (`pi.extensions`, `pi.skills`, `pi.prompts`) and runs the native build in `postinstall`.
 
 Verify:
 
+### macOS / Linux
 ```bash
 ~/.pi/memory/pi-memory --version
 ```
 
-## Option B: single curl command
+### Windows (PowerShell)
+```powershell
+$env:USERPROFILE\.pi\memory\pi-memory.exe --version
+```
+
+## Option B: Unix convenience installer
 
 ```bash
 curl -fsSL https://raw.githubusercontent.com/SiliconState/Pi-Memory/main/scripts/install.sh | bash
 ```
 
-The installer script runs `pi install ...` and falls back to direct compile if needed.
+The shell installer is **Unix-only**. On Windows, use Option A or the manual compile step below.
 
 ## npm/bun status
 
 npm/bun publish is planned but not currently live.
 
-Use Option A (`pi install git:...`) or Option B (curl installer) for now.
+Use Option A (`pi install git:...`) for now.
 
 ## Native build output
 
-Default binary location:
-
+### macOS / Linux
 ```text
 ~/.pi/memory/pi-memory
+~/.pi/memory/memory.db
 ```
 
-Database:
-
+### Windows
 ```text
-~/.pi/memory/memory.db
+%USERPROFILE%\.pi\memory\pi-memory.exe
+%USERPROFILE%\.pi\memory\memory.db
 ```
 
 Override binary path with:
 
+### macOS / Linux
 ```bash
 export PI_MEMORY_BIN=/custom/path/pi-memory
 ```
 
+### Windows (PowerShell)
+```powershell
+$env:PI_MEMORY_BIN = 'C:\custom\path\pi-memory.exe'
+```
+
 ## Troubleshooting
 
 ### `Failed to compile pi-memory`
 
-Install build prerequisites and rerun the installer:
+Install a basic C compiler and rerun:
 
 ```bash
 pi install git:github.com/SiliconState/Pi-Memory
 ```
 
-If needed, compile manually:
+Or from the package directory:
+
+```bash
+npm run setup
+```
+
+### Manual compile — macOS / Linux
 
 ```bash
 PKG="$HOME/.pi/agent/git/github.com/SiliconState/Pi-Memory"
 [ -d "$PKG" ] || PKG="$HOME/.pi/git/github.com/SiliconState/Pi-Memory"
 mkdir -p "$HOME/.pi/memory"
 cc -Wall -Wextra -Wpedantic -O2 -std=c11 -o "$HOME/.pi/memory/pi-memory" \
-  "$PKG/native/pi-memory.c" "$PKG/native/sqlite3.c" -lpthread -ldl -lm
+  "$PKG/native/pi-memory.c" "$PKG/native/sqlite3.c" "$PKG/native/getopt_compat.c" -lpthread -ldl -lm
 chmod +x "$HOME/.pi/memory/pi-memory"
 ```
 
+### Manual compile — Windows (PowerShell + clang/gcc)
+
+```powershell
+$pkg = "$env:USERPROFILE\.pi\agent\git\github.com\SiliconState\Pi-Memory"
+if (-not (Test-Path $pkg)) { $pkg = (Resolve-Path ".\Pi-Memory").Path }
+New-Item -ItemType Directory -Force -Path "$env:USERPROFILE\.pi\memory" | Out-Null
+clang -D_CRT_SECURE_NO_WARNINGS -Wall -Wextra -Wpedantic -O2 -std=c11 `
+  -o "$env:USERPROFILE\.pi\memory\pi-memory.exe" `
+  "$pkg\native\pi-memory.c" "$pkg\native\sqlite3.c" "$pkg\native\getopt_compat.c"
+```
+
+### Manual compile — Windows (Developer PowerShell + MSVC `cl`)
+
+```powershell
+$pkg = "$env:USERPROFILE\.pi\agent\git\github.com\SiliconState\Pi-Memory"
+if (-not (Test-Path $pkg)) { $pkg = (Resolve-Path ".\Pi-Memory").Path }
+New-Item -ItemType Directory -Force -Path "$env:USERPROFILE\.pi\memory" | Out-Null
+cl /nologo /D_CRT_SECURE_NO_WARNINGS /O2 /W4 /EHsc `
+  /Fe:"$env:USERPROFILE\.pi\memory\pi-memory.exe" `
+  "$pkg\native\pi-memory.c" "$pkg\native\sqlite3.c" "$pkg\native\getopt_compat.c"
+```
+
 ### Extension can’t find binary
 
 Set explicit path:
 
+#### macOS / Linux
 ```bash
 export PI_MEMORY_BIN="$HOME/.pi/memory/pi-memory"
 ```
 
+#### Windows (PowerShell)
+```powershell
+$env:PI_MEMORY_BIN = "$env:USERPROFILE\.pi\memory\pi-memory.exe"
+```
+
 ### Check health quickly
 
+#### macOS / Linux
 ```bash
 ~/.pi/memory/pi-memory --version
 ~/.pi/memory/pi-memory help
 ```
+
+#### Windows (PowerShell)
+```powershell
+$env:USERPROFILE\.pi\memory\pi-memory.exe --version
+$env:USERPROFILE\.pi\memory\pi-memory.exe help
+```

extensions/pi-memory-compact.ts

@@ -13,6 +13,8 @@
 import { complete, type Model } from "@mariozechner/pi-ai";
 import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
 import { convertToLlm, serializeConversation } from "@mariozechner/pi-coding-agent";
+import { existsSync, readFileSync } from "node:fs";
+import os from "node:os";
 import path from "node:path";
 
 const DEFAULT_COMPACT_THRESHOLD = parseThresholdValue(process.env.PI_COMPACT_THRESHOLD, 0.6); // 60% default
@@ -74,6 +76,19 @@ function formatThresholdPercent(ratio: number): string {
 }
 
 function getProjectKey(cwd: string): string {
+  const pinned = process.env.PI_MEMORY_PROJECT?.trim();
+  if (pinned) return pinned;
+
+  try {
+    const memoryFile = path.join(cwd, "MEMORY.md");
+    if (existsSync(memoryFile)) {
+      const header = readFileSync(memoryFile, "utf8").match(/^#\s+Memory\s+[—-]\s+(.+)$/m)?.[1]?.trim();
+      if (header) return header;
+    }
+  } catch {
+    // Non-fatal; fall back to cwd basename.
+  }
+
   return path.basename(cwd);
 }
 
@@ -82,7 +97,8 @@ async function execPiMemory(
   args: string[],
   options?: { timeout?: number; signal?: AbortSignal }
 ) {
-  const preferred = process.env.PI_MEMORY_BIN?.trim() || path.join(process.env.HOME ?? "", ".pi", "memory", "pi-memory");
+  const defaultBinary = process.platform === "win32" ? "pi-memory.exe" : "pi-memory";
+  const preferred = process.env.PI_MEMORY_BIN?.trim() || path.join(os.homedir(), ".pi", "memory", defaultBinary);
 
   if (preferred) {
     const result = await pi.exec(preferred, args, options);

native/Makefile

@@ -7,7 +7,7 @@
 CC      = cc
 CFLAGS  = -Wall -Wextra -Wpedantic -O2 -std=c11
 TARGET  = pi-memory
-SRC     = pi-memory.c sqlite3.c
+SRC     = pi-memory.c sqlite3.c getopt_compat.c
 INSTALL_DIR = $(HOME)/.pi/memory
 
 $(TARGET): $(SRC) sqlite3.h