chore(config): update default model to deepseek-v4-flash

.env.example

@@ -1,6 +1,6 @@
 # gai configuration
 GAI_API_KEY=sk-your-api-key-here
-GAI_API_BASE=https://api.openai.com/v1
-GAI_MODEL=gpt-4o
+GAI_API_BASE=https://api.deepseek.com/v1
+GAI_MODEL=deepseek-v4-flash
 GAI_MAX_TOKENS=500
 GAI_TEMPERATURE=0.7

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 mplan
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,15 +1,176 @@
-# git-ai
+<div align="center">
 
-To install dependencies:
+# gai
+
+**AI-powered git commit message generator**
+
+[![Version](https://img.shields.io/badge/version-0.1.0-blue.svg)](https://github.com/mplan/git-ai)
+[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](./LICENSE)
+[![Bun](https://img.shields.io/badge/runtime-Bun-f9d71c.svg)](https://bun.sh)
+[![TypeScript](https://img.shields.io/badge/lang-TypeScript-3178c6.svg)](https://www.typescriptlang.org/)
+
+Generate **Conventional Commits** messages using AI — based on your project context, code diff, and commit history.
+
+</div>
+
+---
+
+## Features
+
+- **3-layer context** — project overview, staged diff, and recent commit history
+- **Conventional Commits** — `feat(scope): description` format by default
+- **Interactive file selection** — ↑/↓ to navigate, space to select, top-level "Select all"
+- **OpenAI-compatible API** — works with DeepSeek, OpenAI, Ollama, and more
+- **Review before commit** — confirm, edit, or abort the generated message
+- **Zero dependencies** — built entirely on Bun native APIs
+
+## Quick Start
 
 ```bash
+# Install dependencies
 bun install
+
+# Configure your API key
+bun run gai config
+
+# Generate a commit message
+bun run gai
 ```
 
-To run:
+## Usage
+
+```
+gai                Generate commit message (interactive file selection)
+gai --auto         Auto-stage all changed files
+gai --dry-run      Generate message without committing
+gai config         Configure API settings
+gai --help         Show help
+gai --version      Show version
+```
+
+### Interactive Flow
+
+```
+$ gai
+
+  Select files to stage:
+    ❯ ◉ Select all
+      ◉ src/git.ts (modified)
+      ○ src/ai.ts (modified)
+      ◉ src/newfile.ts (new)
+
+  ↑/↓ navigate, space select, enter confirm
+
+  Generating commit message...
+
+  Generated commit message:
+    feat(git): add interactive file staging and commit wrapper
+
+  Use this message? [Y/n/e] Y
+
+  Committed successfully!
+```
+
+## Configuration
+
+### Via `gai config` (interactive)
 
 ```bash
-bun run index.ts
+bun run gai config
 ```
 
-This project was created using `bun init` in bun v1.3.14. [Bun](https://bun.com) is a fast all-in-one JavaScript runtime.
+### Via environment variables
+
+| Variable | Default | Description |
+|---|---|---|
+| `GAI_API_KEY` | — | **Required.** Your API key |
+| `GAI_API_BASE` | `https://api.deepseek.com/v1` | API base URL |
+| `GAI_MODEL` | `deepseek-v4-flash` | Model name |
+| `GAI_MAX_TOKENS` | `500` | Max response tokens |
+| `GAI_TEMPERATURE` | `0.7` | Sampling temperature |
+
+### Via `.env` file
+
+Bun auto-loads `.env` — no dotenv needed:
+
+```bash
+GAI_API_KEY=sk-your-key
+GAI_API_BASE=https://api.deepseek.com/v1
+GAI_MODEL=deepseek-v4-flash
+```
+
+### Using other providers
+
+<details>
+<summary><strong>OpenAI</strong></summary>
+
+```bash
+GAI_API_KEY=sk-xxx
+GAI_API_BASE=https://api.openai.com/v1
+GAI_MODEL=gpt-4o
+```
+
+</details>
+
+<details>
+<summary><strong>Ollama (local)</strong></summary>
+
+```bash
+GAI_API_KEY=ollama
+GAI_API_BASE=http://localhost:11434/v1
+GAI_MODEL=llama3
+```
+
+</details>
+
+<details>
+<summary><strong>OpenRouter</strong></summary>
+
+```bash
+GAI_API_KEY=sk-or-xxx
+GAI_API_BASE=https://openrouter.ai/api/v1
+GAI_MODEL=anthropic/claude-sonnet-4
+```
+
+</details>
+
+## How It Works
+
+```
+┌─────────────────────────────────────────────┐
+│                gai                           │
+├─────────────────────────────────────────────┤
+│  1. Collect project context                  │
+│     ├─ README.md / package.json              │
+│     └─ Directory structure                   │
+│                                              │
+│  2. Collect code changes                     │
+│     └─ git diff --staged                     │
+│                                              │
+│  3. Collect commit history                   │
+│     └─ git log --oneline -10                 │
+│                                              │
+│  4. Build prompt → Call AI API               │
+│                                              │
+│  5. Review → Confirm → Commit                │
+└─────────────────────────────────────────────┘
+```
+
+## Build
+
+Compile to a standalone binary:
+
+```bash
+bun run build
+# Output: ./gai
+```
+
+## Test
+
+```bash
+bun test
+```
+
+## License
+
+[MIT](./LICENSE)

index.ts

@@ -37,8 +37,8 @@ ${BOLD}Usage:${RESET}
 ${BOLD}Configuration:${RESET}
   Set via ${CYAN}gai config${RESET} or environment variables:
     GAI_API_KEY      OpenAI-compatible API key
-    GAI_API_BASE     API base URL (default: https://api.openai.com/v1)
-    GAI_MODEL        Model name (default: gpt-4o)
+    GAI_API_BASE     API base URL (default: https://api.deepseek.com/v1)
+    GAI_MODEL        Model name (default: deepseek-v4-flash)
     GAI_MAX_TOKENS   Max tokens (default: 500)
     GAI_TEMPERATURE  Temperature (default: 0.7)
 `);
@@ -105,10 +105,152 @@ async function confirmCommit(message: string): Promise<"y" | "n" | "e"> {
 }
 
 async function editMessage(current: string): Promise<string | null> {
-  console.log(`  Current: ${DIM}${current}${RESET}`);
-  console.log(`  Enter new message (empty to abort):`);
-  const newMsg = await ask("  > ");
-  return newMsg || null;
+  if (!process.stdin.isTTY) return null;
+
+  process.stdout.write(`  ${DIM}Edit message (Enter to confirm, Esc to abort):${RESET}\n`);
+
+  const savedRaw = process.stdin.isRaw;
+  process.stdin.setRawMode(true);
+  process.stdin.resume();
+
+  let buffer = current;
+  let cursor = current.length;
+  const ESC = "\x1b";
+  const ENTER = "\r";
+  const CTRL_C = "\x03";
+  const BACKSPACE = "\x7f";
+  const DELETE = "\x1b[3~";
+  const LEFT = "\x1b[D";
+  const RIGHT = "\x1b[C";
+  const HOME = "\x1b[H" /* or \x01 */;
+  const END = "\x1b[F" /* or \x05 */;
+
+  function render() {
+    process.stdout.write("\x1b[2K\r  > " + buffer);
+    if (cursor < buffer.length) {
+      process.stdout.write(`\x1b[${buffer.length - cursor}D`);
+    }
+  }
+
+  process.stdout.write("  > ");
+  process.stdout.write(buffer);
+
+  return new Promise((resolve) => {
+    let escapeBuf = "";
+
+    function handleSeq(seq: string) {
+      if (seq === "\x1b[D" || seq === "\x1bOD") {
+        if (cursor > 0) {
+          cursor--;
+          process.stdout.write("\x1b[D");
+        }
+      } else if (seq === "\x1b[C" || seq === "\x1bOC") {
+        if (cursor < buffer.length) {
+          cursor++;
+          process.stdout.write("\x1b[C");
+        }
+      } else if (seq === "\x1b[H" || seq === "\x1b[1~" || seq === "\x1bOH") {
+        if (cursor > 0) {
+          process.stdout.write(`\x1b[${cursor}D`);
+          cursor = 0;
+        }
+      } else if (seq === "\x1b[F" || seq === "\x1b[4~" || seq === "\x1bOF") {
+        if (cursor < buffer.length) {
+          process.stdout.write(`\x1b[${buffer.length - cursor}C`);
+          cursor = buffer.length;
+        }
+      } else if (seq === "\x1b[3~") {
+        if (cursor < buffer.length) {
+          buffer = buffer.slice(0, cursor) + buffer.slice(cursor + 1);
+          render();
+        }
+      }
+    }
+
+    process.stdin.on("data", (data: Buffer) => {
+      const key = data.toString();
+
+      if (key === CTRL_C) {
+        process.stdin.setRawMode(savedRaw === true);
+        process.stdin.pause();
+        process.stdin.removeAllListeners("data");
+        process.stdout.write("\n");
+        resolve(null);
+        return;
+      }
+
+      if (key === ESC || key.startsWith("\x1b[")) {
+        escapeBuf = key;
+        if (key.length >= 3) {
+          handleSeq(key);
+          escapeBuf = "";
+        }
+        return;
+      }
+
+      if (escapeBuf) {
+        escapeBuf += key;
+        if (/^[A-Za-z~]$/.test(key)) {
+          handleSeq(escapeBuf);
+          escapeBuf = "";
+        } else if (escapeBuf.length > 8) {
+          escapeBuf = "";
+        }
+        return;
+      }
+
+      if (key === ENTER) {
+        process.stdin.setRawMode(savedRaw === true);
+        process.stdin.pause();
+        process.stdin.removeAllListeners("data");
+        process.stdout.write("\n");
+        const result = buffer.trim();
+        resolve(result || null);
+        return;
+      }
+
+      if (key === BACKSPACE) {
+        if (cursor > 0) {
+          buffer = buffer.slice(0, cursor - 1) + buffer.slice(cursor);
+          cursor--;
+          render();
+        }
+        return;
+      }
+
+      if (key === "\x01") {
+        if (cursor > 0) {
+          process.stdout.write(`\x1b[${cursor}D`);
+          cursor = 0;
+        }
+        return;
+      }
+      if (key === "\x05") {
+        if (cursor < buffer.length) {
+          process.stdout.write(`\x1b[${buffer.length - cursor}C`);
+          cursor = buffer.length;
+        }
+        return;
+      }
+      if (key === "\x0b") {
+        buffer = buffer.slice(0, cursor);
+        render();
+        return;
+      }
+      if (key === "\x15") {
+        buffer = buffer.slice(cursor);
+        cursor = 0;
+        render();
+        return;
+      }
+
+      if (key.charCodeAt(0) >= 32 && key.charCodeAt(0) < 127) {
+        buffer = buffer.slice(0, cursor) + key + buffer.slice(cursor);
+        cursor++;
+        render();
+      }
+    });
+  });
 }
 
 async function main() {
@@ -213,12 +355,32 @@ async function main() {
     return;
   }
 
+function printCommitResult(
+  result: { branch: string; hash: string; files: number; insertions: number; deletions: number },
+  msg: string,
+) {
+  console.log(`\n  ${GREEN}${BOLD}✔ Committed successfully!${RESET}`);
+
+  const id = result.branch && result.hash
+    ? `${YELLOW}[${result.branch} ${result.hash}]${RESET}`
+    : result.hash
+      ? `${YELLOW}${result.hash}${RESET}`
+      : "";
+  console.log(`    ${id}  ${msg}`);
+
+  const parts: string[] = [];
+  if (result.files > 0) parts.push(`${YELLOW}${result.files} file${result.files > 1 ? "s" : ""} changed${RESET}`);
+  if (result.insertions > 0) parts.push(`${GREEN}${result.insertions} insertion${result.insertions > 1 ? "s" : ""}(+)${RESET}`);
+  if (result.deletions > 0) parts.push(`${RED}${result.deletions} deletion${result.deletions > 1 ? "s" : ""}(-)${RESET}`);
+  if (parts.length > 0) console.log(`    ${parts.join(", ")}`);
+}
+
   const action = await confirmCommit(message);
 
   if (action === "y") {
     try {
-      await commit(message);
-      console.log(`\n  ${GREEN}Committed successfully!${RESET}`);
+      const result = await commit(message);
+      printCommitResult(result, message);
     } catch (err) {
       console.error(
         `  ${RED}Commit failed: ${err instanceof Error ? err.message : err}${RESET}`,
@@ -229,8 +391,8 @@ async function main() {
     const edited = await editMessage(message);
     if (edited) {
       try {
-        await commit(edited);
-        console.log(`\n  ${GREEN}Committed successfully!${RESET}`);
+        const result = await commit(edited);
+        printCommitResult(result, edited);
       } catch (err) {
         console.error(
           `  ${RED}Commit failed: ${err instanceof Error ? err.message : err}${RESET}`,

src/ai.ts

@@ -8,15 +8,42 @@ interface ChatMessage {
 interface ChatCompletionResponse {
   choices?: Array<{
     message?: {
-      content?: string;
+      content?: string | null;
     };
+    finish_reason?: string;
   }>;
+  error?: {
+    message?: string;
+    type?: string;
+    code?: string;
+  };
+}
+
+const MAX_RETRIES = 3;
+const RETRY_DELAY = 1000;
+
+function cleanMessage(raw: string): string {
+  let msg = raw.trim();
+  if (msg.startsWith("```") && msg.endsWith("```")) {
+    const lines = msg.split("\n");
+    if (lines.length > 2) {
+      lines.shift();
+      lines.pop();
+      msg = lines.join("\n").trim();
+    }
+  }
+  return msg;
+}
+
+async function sleep(ms: number) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
 export async function generateCommitMessage(
   config: Config,
   systemPrompt: string,
   userPrompt: string,
+  retries = MAX_RETRIES,
 ): Promise<string> {
   const url = `${config.apiBase.replace(/\/$/, "")}/chat/completions`;
 
@@ -25,6 +52,8 @@ export async function generateCommitMessage(
     { role: "user", content: userPrompt },
   ];
 
+  for (let attempt = 1; attempt <= retries; attempt++) {
+    try {
       const response = await fetch(url, {
         method: "POST",
         headers: {
@@ -41,15 +70,54 @@ export async function generateCommitMessage(
 
       if (!response.ok) {
         const text = await response.text();
+        if (response.status === 429 && attempt < retries) {
+          await sleep(RETRY_DELAY * attempt);
+          continue;
+        }
         throw new Error(`API request failed (${response.status}): ${text}`);
       }
 
       const data = (await response.json()) as ChatCompletionResponse;
-  const message = data.choices?.[0]?.message?.content?.trim();
 
-  if (!message) {
-    throw new Error("Empty response from AI");
+      if (data.error) {
+        throw new Error(
+          `API error: ${data.error.message ?? JSON.stringify(data.error)}`,
+        );
       }
 
-  return message;
+      const raw = data.choices?.[0]?.message?.content;
+      const finishReason = data.choices?.[0]?.finish_reason;
+
+      if (raw && raw.trim()) {
+        return cleanMessage(raw);
+      }
+
+      if (finishReason === "length") {
+        throw new Error(
+          "Response truncated (max_tokens too low). Try increasing GAI_MAX_TOKENS.",
+        );
+      }
+
+      if (finishReason === "content_filter") {
+        throw new Error("Response blocked by content filter.");
+      }
+
+      if (attempt < retries) {
+        await sleep(RETRY_DELAY * attempt);
+        continue;
+      }
+
+      throw new Error(
+        `Empty response from AI after ${retries} attempts. finish_reason: ${finishReason ?? "unknown"}`,
+      );
+    } catch (err) {
+      if (attempt >= retries) throw err;
+      if (err instanceof Error && err.message.startsWith("API error")) throw err;
+      if (err instanceof Error && err.message.includes("max_tokens")) throw err;
+      if (err instanceof Error && err.message.includes("content filter")) throw err;
+      await sleep(RETRY_DELAY * attempt);
+    }
+  }
+
+  throw new Error("Failed to generate commit message");
 }

src/config.ts

@@ -5,8 +5,8 @@ import type { Config } from "./types";
 
 const DEFAULT_CONFIG: Config = {
   apiKey: "",
-  apiBase: "https://api.openai.com/v1",
-  model: "gpt-4o",
+  apiBase: "https://api.deepseek.com/v1",
+  model: "deepseek-v4-flash",
   maxTokens: 500,
   temperature: 0.7,
 };

src/git.ts

@@ -98,13 +98,34 @@ export async function stageFiles(paths: string[]): Promise<void> {
   await Bun.$`git add -- ${paths}`;
 }
 
-export async function commit(message: string): Promise<void> {
+export async function commit(
+  message: string,
+): Promise<{ branch: string; hash: string; files: number; insertions: number; deletions: number }> {
   const proc = Bun.spawn(["git", "commit", "-m", message], {
-    stdout: "inherit",
-    stderr: "inherit",
+    stdout: "pipe",
+    stderr: "pipe",
   });
   const exitCode = await proc.exited;
+  const stdout = await new Response(proc.stdout).text();
+  const stderr = await new Response(proc.stderr).text();
+
   if (exitCode !== 0) {
-    throw new Error(`git commit failed (exit code ${exitCode})`);
+    throw new Error(stderr.trim() || `git commit failed (exit code ${exitCode})`);
   }
+
+  const branchHashMatch = stdout.match(/\[(\S+)\s+([0-9a-f]{7,})/);
+  const branch = branchHashMatch?.[1] ?? "";
+  const hash = branchHashMatch?.[2] ?? "";
+
+  const filesMatch = stdout.match(/(\d+)\s+file/);
+  const insertionsMatch = stdout.match(/(\d+)\s+insertion/);
+  const deletionsMatch = stdout.match(/(\d+)\s+deletion/);
+
+  return {
+    branch,
+    hash,
+    files: parseInt(filesMatch?.[1] ?? "0"),
+    insertions: parseInt(insertionsMatch?.[1] ?? "0"),
+    deletions: parseInt(deletionsMatch?.[1] ?? "0"),
+  };
 }

src/selector.ts

@@ -1,6 +1,37 @@
-import * as readline from "node:readline";
 import type { FileEntry } from "./types";
-import { BOLD, GREEN, YELLOW, CYAN, RESET } from "./terminal";
+import { BOLD, GREEN, YELLOW, CYAN, DIM, RESET } from "./terminal";
+
+const UP = "\x1b[A";
+const DOWN = "\x1b[B";
+const SPACE = " ";
+const ENTER = "\r";
+const CTRL_C = "\x03";
+
+function hideCursor() {
+  process.stdout.write("\x1b[?25l");
+}
+
+function showCursor() {
+  process.stdout.write("\x1b[?25h");
+}
+
+function moveUp(n: number) {
+  process.stdout.write(`\x1b[${n}A`);
+}
+
+function moveDown(n: number) {
+  process.stdout.write(`\x1b[${n}B`);
+}
+
+function clearLine() {
+  process.stdout.write("\x1b[2K\r");
+}
+
+interface SelectItem {
+  label: string;
+  path: string;
+  selected: boolean;
+}
 
 export async function selectFiles(
   stagedFiles: FileEntry[],
@@ -9,54 +40,129 @@ export async function selectFiles(
   if (unstagedFiles.length === 0) return [];
 
   if (stagedFiles.length > 0) {
-    console.log(`\n  ${BOLD}Staged files (will be included):${RESET}`);
+    process.stdout.write(`\n  ${BOLD}Staged files (will be included):${RESET}\n`);
     for (const f of stagedFiles) {
-      console.log(`    ${GREEN}✓${RESET} ${f.path} (${YELLOW}${f.label}${RESET})`);
+      process.stdout.write(`    ${GREEN}✓${RESET} ${f.path} (${YELLOW}${f.label}${RESET})\n`);
     }
   }
 
-  console.log(`\n  ${BOLD}Unstaged files:${RESET}`);
-  for (let i = 0; i < unstagedFiles.length; i++) {
-    const f = unstagedFiles[i]!;
-    console.log(
-      `    ${CYAN}${i + 1}.${RESET} ${f.path} (${YELLOW}${f.label}${RESET})`,
-    );
+  const items: SelectItem[] = [
+    { label: "Select all", path: "__all__", selected: false },
+    ...unstagedFiles.map((f) => ({
+      label: `${f.path} (${f.label})`,
+      path: f.path,
+      selected: false,
+    })),
+  ];
+
+  let cursor = 0;
+
+  process.stdout.write(`\n  ${BOLD}Select files to stage:${RESET}\n`);
+  process.stdout.write(`  ${DIM}↑/↓ navigate, space select, enter confirm${RESET}\n\n`);
+
+  const itemStartRow = 4 + (stagedFiles.length > 0 ? stagedFiles.length + 2 : 0);
+
+  function render() {
+    for (let i = 0; i < items.length; i++) {
+      process.stdout.write("\x1b[2K\r");
+      const item = items[i]!;
+      const isAll = i === 0;
+      const cursor_ = i === cursor ? `${CYAN}❯${RESET} ` : "  ";
+      const checkbox = item.selected ? `${GREEN}◉${RESET}` : `${DIM}○${RESET}`;
+
+      if (isAll) {
+        process.stdout.write(`${cursor_} ${checkbox} ${BOLD}${item.label}${RESET}\n`);
+      } else {
+        process.stdout.write(`${cursor_} ${checkbox} ${item.path.includes("(") ? item.label : `${item.label}`}\n`);
+      }
+    }
+    moveUp(items.length);
   }
 
-  console.log("");
-  const rl = readline.createInterface({
-    input: process.stdin,
-    output: process.stdout,
-  });
+  function toggleItem(index: number) {
+    const item = items[index]!;
+    item.selected = !item.selected;
+
+    if (index === 0) {
+      for (let i = 1; i < items.length; i++) {
+        items[i]!.selected = item.selected;
+      }
+    } else {
+      const allSelected = items.slice(1).every((it) => it.selected);
+      items[0]!.selected = allSelected;
+    }
+  }
 
   return new Promise((resolve) => {
-    rl.question(
-      "  Enter files to stage (e.g. 1,3) or 'a' for all: ",
-      (answer) => {
-        rl.close();
-        const trimmed = answer.trim().toLowerCase();
-
-        if (trimmed === "a" || trimmed === "all") {
-          resolve(unstagedFiles.map((f) => f.path));
-          return;
-        }
-
-        if (trimmed === "") {
+    if (process.stdin.isTTY !== true) {
       resolve([]);
       return;
     }
 
-        const indices = trimmed
-          .split(/[,\s]+/)
-          .map((s) => parseInt(s.trim()))
-          .filter(
-            (n) => !isNaN(n) && n >= 1 && n <= unstagedFiles.length,
-          )
-          .map((n) => n - 1);
+    const wasRaw = process.stdin.isRaw;
+    if (wasRaw !== true) {
+      process.stdin.setRawMode(true);
+    }
+    process.stdin.resume();
+    hideCursor();
 
-        const uniqueIndices = [...new Set(indices)];
-        resolve(uniqueIndices.map((i) => unstagedFiles[i]!.path));
-      },
+    render();
+
+    const onData = (data: Buffer) => {
+      const key = data.toString();
+
+      if (key === CTRL_C) {
+        process.stdin.setRawMode(wasRaw === true);
+        process.stdin.pause();
+        process.stdin.removeListener("data", onData);
+        showCursor();
+        for (let i = 0; i < items.length; i++) {
+          process.stdout.write("\x1b[2K\n");
+        }
+        moveUp(items.length);
+        process.stdout.write(`\n  Aborted.\n`);
+        process.exit(1);
+      }
+
+      if (key === UP) {
+        if (cursor > 0) {
+          cursor--;
+          render();
+        }
+      } else if (key === DOWN) {
+        if (cursor < items.length - 1) {
+          cursor++;
+          render();
+        }
+      } else if (key === SPACE) {
+        toggleItem(cursor);
+        render();
+      } else if (key === ENTER) {
+        process.stdin.setRawMode(wasRaw === true);
+        process.stdin.pause();
+        process.stdin.removeListener("data", onData);
+
+        for (let i = 0; i < items.length; i++) {
+          process.stdout.write("\x1b[2K\n");
+        }
+        moveUp(items.length);
+
+        const selected = items
+          .slice(1)
+          .filter((it) => it.selected)
+          .map((it) => it.path);
+
+        if (selected.length > 0) {
+          process.stdout.write(
+            `  ${GREEN}Staged ${selected.length} file(s):${RESET} ${selected.join(", ")}\n`,
           );
+        }
+
+        showCursor();
+        resolve(selected);
+      }
+    };
+
+    process.stdin.on("data", onData);
   });
 }

test/config.test.ts

@@ -0,0 +1,40 @@
+import { test, expect, describe } from "bun:test";
+import { loadConfig } from "../src/config";
+
+describe("config", () => {
+  test("loadConfig env variables override config file and defaults", async () => {
+    const origBase = process.env.GAI_API_BASE;
+    const origModel = process.env.GAI_MODEL;
+
+    process.env.GAI_API_BASE = "https://custom.api.com/v1";
+    process.env.GAI_MODEL = "custom-model";
+
+    const config = await loadConfig();
+
+    expect(config.apiBase).toBe("https://custom.api.com/v1");
+    expect(config.model).toBe("custom-model");
+
+    if (origBase) process.env.GAI_API_BASE = origBase;
+    else delete process.env.GAI_API_BASE;
+    if (origModel) process.env.GAI_MODEL = origModel;
+    else delete process.env.GAI_MODEL;
+  });
+
+  test("loadConfig reads from environment variables", async () => {
+    const origBase = process.env.GAI_API_BASE;
+    const origModel = process.env.GAI_MODEL;
+
+    process.env.GAI_API_BASE = "https://api.deepseek.com/v1";
+    process.env.GAI_MODEL = "deepseek-v4-flash";
+
+    const config = await loadConfig();
+
+    expect(config.apiBase).toBe("https://api.deepseek.com/v1");
+    expect(config.model).toBe("deepseek-v4-flash");
+
+    if (origBase) process.env.GAI_API_BASE = origBase;
+    else delete process.env.GAI_API_BASE;
+    if (origModel) process.env.GAI_MODEL = origModel;
+    else delete process.env.GAI_MODEL;
+  });
+});

test/prompt.test.ts

@@ -0,0 +1,64 @@
+import { test, expect, describe } from "bun:test";
+import { buildPrompt, SYSTEM_PROMPT } from "../src/prompt";
+import type { ProjectContext } from "../src/types";
+
+describe("prompt", () => {
+  test("SYSTEM_PROMPT contains Conventional Commits format", () => {
+    expect(SYSTEM_PROMPT).toContain("<type>(<scope>)");
+    expect(SYSTEM_PROMPT).toContain("feat");
+    expect(SYSTEM_PROMPT).toContain("fix");
+  });
+
+  test("buildPrompt with full context", () => {
+    const ctx: ProjectContext = {
+      readme: "A test project",
+      packageDescription: "Test package",
+      structure: "src/, tests/",
+      recentCommits: ["abc123 feat: initial commit"],
+      diff: "+new line\n-old line",
+    };
+
+    const prompt = buildPrompt(ctx);
+
+    expect(prompt).toContain("## Project Context");
+    expect(prompt).toContain("Test package");
+    expect(prompt).toContain("src/, tests/");
+    expect(prompt).toContain("A test project");
+    expect(prompt).toContain("## Recent Commits");
+    expect(prompt).toContain("abc123 feat: initial commit");
+    expect(prompt).toContain("## Staged Changes");
+    expect(prompt).toContain("+new line");
+    expect(prompt).toContain("Generate a commit message");
+  });
+
+  test("buildPrompt with minimal context (only diff)", () => {
+    const ctx: ProjectContext = {
+      readme: null,
+      packageDescription: null,
+      structure: null,
+      recentCommits: [],
+      diff: "+added code",
+    };
+
+    const prompt = buildPrompt(ctx);
+
+    expect(prompt).not.toContain("## Project Context");
+    expect(prompt).not.toContain("## Recent Commits");
+    expect(prompt).toContain("## Staged Changes");
+    expect(prompt).toContain("+added code");
+  });
+
+  test("buildPrompt includes diff as-is (truncation is caller's responsibility)", () => {
+    const diff = "+short diff content";
+    const ctx: ProjectContext = {
+      readme: null,
+      packageDescription: null,
+      structure: null,
+      recentCommits: [],
+      diff,
+    };
+
+    const prompt = buildPrompt(ctx);
+    expect(prompt).toContain(diff);
+  });
+});