feat(cli): help agents keep Hunk skills in sync (#190)

Author: benvinegar

CHANGELOG.md

@@ -6,8 +6,12 @@ All notable user-visible changes to Hunk are documented in this file.
 
 ### Added
 
+- Added `hunk skill path` to print the bundled Hunk review skill path for direct loading or symlinking in coding agents.
+
 ### Changed
 
+- Show a one-time startup notice after version changes that points users with copied agent skills to `hunk skill path`.
+
 ### Fixed
 
 ## [0.9.1] - 2026-04-10

README.md

@@ -69,6 +69,8 @@ git diff --no-color | hunk patch -          # review a patch from stdin
 
 Load the [`skills/hunk-review/SKILL.md`](skills/hunk-review/SKILL.md) skill in your coding agent (e.g. Claude, Codex, Opencode, Pi).
 
+Run `hunk skill path` to print the installed bundled skill path. Prefer loading or symlinking that file in your agent instead of copying it so Hunk upgrades stay in sync automatically.
+
 Open Hunk in another window, then ask your agent to leave comments.
 
 ## Feature comparison
@@ -144,6 +146,7 @@ Hunk supports two agent workflows:
 #### Steer a live Hunk window
 
 Use the Hunk review skill: [`skills/hunk-review/SKILL.md`](skills/hunk-review/SKILL.md).
+If you need the installed absolute path for your agent setup, run `hunk skill path`.
 
 A good generic prompt is:
 

bin/hunk.cjs

@@ -5,6 +5,10 @@ const fs = require("node:fs");
 const os = require("node:os");
 const path = require("node:path");
 
+function bundledSkillPath() {
+  return path.join(__dirname, "..", "skills", "hunk-review", "SKILL.md");
+}
+
 function ensureExecutable(target) {
   if (process.platform === "win32") {
     return;
@@ -94,21 +98,33 @@ function bundledBunRuntime() {
   }
 }
 
+const forwardedArgs = process.argv.slice(2);
+if (forwardedArgs.length === 2 && forwardedArgs[0] === "skill" && forwardedArgs[1] === "path") {
+  const skillPath = bundledSkillPath();
+  if (!fs.existsSync(skillPath)) {
+    console.error(`hunk: could not locate the bundled Hunk review skill at ${skillPath}`);
+    process.exit(1);
+  }
+
+  process.stdout.write(`${skillPath}\n`);
+  process.exit(0);
+}
+
 const overrideBinary = process.env.HUNK_BIN_PATH;
 if (overrideBinary) {
-  run(overrideBinary, process.argv.slice(2));
+  run(overrideBinary, forwardedArgs);
 }
 
 const scriptDir = path.dirname(fs.realpathSync(__filename));
 const prebuiltBinary = findInstalledBinary(scriptDir);
 if (prebuiltBinary) {
-  run(prebuiltBinary, process.argv.slice(2));
+  run(prebuiltBinary, forwardedArgs);
 }
 
 const bunBinary = bundledBunRuntime();
 if (bunBinary) {
   const entrypoint = path.join(__dirname, "..", "dist", "npm", "main.js");
-  run(bunBinary, [entrypoint, ...process.argv.slice(2)]);
+  run(bunBinary, [entrypoint, ...forwardedArgs]);
 }
 
 const printablePackages = hostCandidates()

scripts/check-prebuilt-pack.ts

@@ -63,7 +63,13 @@ if (!existsSync(metaDir)) {
 }
 
 const metaPack = runPackDryRun(metaDir);
-assertPaths(metaPack, ["bin/hunk.cjs", "README.md", "LICENSE", "package.json"]);
+assertPaths(metaPack, [
+  "bin/hunk.cjs",
+  "skills/hunk-review/SKILL.md",
+  "README.md",
+  "LICENSE",
+  "package.json",
+]);
 
 const packageDirectories = readdirSync(releaseRoot, { withFileTypes: true })
   .filter((entry) => entry.isDirectory() && entry.name !== "hunkdiff")

scripts/smoke-prebuilt-install.ts

@@ -1,6 +1,6 @@
 #!/usr/bin/env bun
 
-import { mkdtempSync, mkdirSync, rmSync } from "node:fs";
+import { existsSync, mkdtempSync, mkdirSync, rmSync } from "node:fs";
 import path from "node:path";
 import { getHostPlatformPackageSpec, releaseNpmDir } from "./prebuilt-package-helpers";
 
@@ -83,6 +83,18 @@ try {
     );
   }
 
+  const skillPath = run([installedHunk, "skill", "path"], {
+    env: commandEnv,
+  }).stdout.trim();
+  if (
+    !skillPath.endsWith(path.join("skills", "hunk-review", "SKILL.md")) ||
+    !existsSync(skillPath)
+  ) {
+    throw new Error(
+      `Expected installed hunk skill path to resolve to the bundled skill.\n${skillPath}`,
+    );
+  }
+
   const bunCheck = Bun.spawnSync(
     [
       resolvedNode,

scripts/stage-prebuilt-npm.ts

@@ -77,6 +77,7 @@ function stageMetaPackage(
   const metaDir = path.join(releaseRoot, rootPackage.name);
   ensureDirectory(path.join(metaDir, "bin"));
   cpSync(path.join(repoRoot, "bin", "hunk.cjs"), path.join(metaDir, "bin", "hunk.cjs"));
+  cpSync(path.join(repoRoot, "skills"), path.join(metaDir, "skills"), { recursive: true });
   cpSync(path.join(repoRoot, "README.md"), path.join(metaDir, "README.md"));
   cpSync(path.join(repoRoot, "LICENSE"), path.join(metaDir, "LICENSE"));
 
@@ -87,7 +88,7 @@ function stageMetaPackage(
     bin: {
       hunk: "./bin/hunk.cjs",
     },
-    files: ["bin", "README.md", "LICENSE"],
+    files: ["bin", "skills", "README.md", "LICENSE"],
     keywords: rootPackage.keywords,
     repository: rootPackage.repository,
     homepage: rootPackage.homepage,

src/core/cli.test.ts

@@ -34,6 +34,7 @@ describe("parseCli", () => {
     expect(parsed.text).toContain("Usage:");
     expect(parsed.text).toContain("hunk diff");
     expect(parsed.text).toContain("hunk show");
+    expect(parsed.text).toContain("hunk skill path");
     expect(parsed.text).toContain("Global options:");
     expect(parsed.text).toContain("Common review options:");
     expect(parsed.text).toContain("auto-reload when the current diff input changes");
@@ -188,6 +189,32 @@ describe("parseCli", () => {
     });
   });
 
+  test("prints the bundled skill path for hunk skill path", async () => {
+    const parsed = await parseCli(["bun", "hunk", "skill", "path"]);
+
+    expect(parsed.kind).toBe("help");
+    if (parsed.kind !== "help") {
+      throw new Error("Expected bundled skill path output.");
+    }
+
+    expect(parsed.text).toEndWith(`${join("skills", "hunk-review", "SKILL.md")}\n`);
+  });
+
+  test("prints skill help for hunk skill --help", async () => {
+    const parsed = await parseCli(["bun", "hunk", "skill", "--help"]);
+
+    expect(parsed).toEqual({
+      kind: "help",
+      text: [
+        "Usage: hunk skill path",
+        "",
+        "Print the bundled Hunk review skill path.",
+        "Load or symlink that file in your coding agent to keep it in sync across Hunk upgrades.",
+        "",
+      ].join("\n"),
+    });
+  });
+
   test("parses the MCP daemon command", async () => {
     const parsed = await parseCli(["bun", "hunk", "mcp", "serve"]);
 

src/core/cli.ts

@@ -10,6 +10,7 @@ import type {
   ParsedCliInput,
   SessionCommentApplyItemInput,
 } from "./types";
+import { resolveBundledHunkReviewSkillPath } from "./paths";
 import { resolveCliVersion } from "./version";
 
 /** Validate one requested layout mode from CLI input. */
@@ -101,6 +102,22 @@ function renderCliVersion() {
   return `${resolveCliVersion()}\n`;
 }
 
+/** Render the bundled Hunk review skill path for shell usage. */
+function renderHunkReviewSkillPath() {
+  return `${resolveBundledHunkReviewSkillPath()}\n`;
+}
+
+/** Build the `hunk skill` help text. */
+function renderSkillHelp() {
+  return [
+    "Usage: hunk skill path",
+    "",
+    "Print the bundled Hunk review skill path.",
+    "Load or symlink that file in your coding agent to keep it in sync across Hunk upgrades.",
+    "",
+  ].join("\n");
+}
+
 /** Build the top-level help text shown by bare `hunk` and `hunk --help`. */
 function renderCliHelp() {
   return [
@@ -118,6 +135,7 @@ function renderCliHelp() {
     "  hunk pager                              general Git pager wrapper with diff detection",
     "  hunk difftool <left> <right> [path]     review Git difftool file pairs",
     "  hunk session <subcommand>               inspect or control a live Hunk session",
+    "  hunk skill path                         print the bundled Hunk review skill path",
     "  hunk mcp serve                          run the local Hunk session daemon",
     "",
     "Global options:",
@@ -1141,6 +1159,37 @@ async function parseSessionCommand(tokens: string[]): Promise<ParsedCliInput> {
   throw new Error(`Unknown session command: ${subcommand}`);
 }
 
+/** Parse `hunk skill ...` for bundled skill discovery commands. */
+async function parseSkillCommand(tokens: string[]): Promise<HelpCommandInput> {
+  const [subcommand, ...rest] = tokens;
+  if (!subcommand || subcommand === "--help" || subcommand === "-h") {
+    return {
+      kind: "help",
+      text: renderSkillHelp(),
+    };
+  }
+
+  if (subcommand !== "path") {
+    throw new Error("Only `hunk skill path` is supported.");
+  }
+
+  if (rest.includes("--help") || rest.includes("-h")) {
+    return {
+      kind: "help",
+      text: renderSkillHelp(),
+    };
+  }
+
+  if (rest.length > 0) {
+    throw new Error("`hunk skill path` does not accept additional arguments.");
+  }
+
+  return {
+    kind: "help",
+    text: renderHunkReviewSkillPath(),
+  };
+}
+
 /** Parse `hunk mcp serve` as the local daemon entrypoint. */
 async function parseMcpCommand(tokens: string[]): Promise<ParsedCliInput> {
   const [subcommand, ...rest] = tokens;
@@ -1258,6 +1307,8 @@ export async function parseCli(argv: string[]): Promise<ParsedCliInput> {
       return parseStashCommand(rest, argv);
     case "session":
       return parseSessionCommand(rest);
+    case "skill":
+      return parseSkillCommand(rest);
     case "mcp":
       return parseMcpCommand(rest);
     default:

src/core/config.ts

@@ -1,5 +1,6 @@
 import fs from "node:fs";
 import { dirname, join, resolve } from "node:path";
+import { resolveGlobalConfigPath } from "./paths";
 import type { CliInput, CommonOptions, LayoutMode, PersistedViewPreferences } from "./types";
 
 const DEFAULT_VIEW_PREFERENCES: PersistedViewPreferences = {
@@ -105,19 +106,6 @@ function findRepoRoot(cwd = process.cwd()) {
   }
 }
 
-/** Resolve the global XDG-style config path, if the environment provides one. */
-function globalConfigPath(env: NodeJS.ProcessEnv = process.env) {
-  if (env.XDG_CONFIG_HOME) {
-    return join(env.XDG_CONFIG_HOME, "hunk", "config.toml");
-  }
-
-  if (env.HOME) {
-    return join(env.HOME, ".config", "hunk", "config.toml");
-  }
-
-  return undefined;
-}
-
 /** Parse one TOML config file into a plain object. */
 function readTomlRecord(path: string) {
   if (!fs.existsSync(path)) {
@@ -139,7 +127,7 @@ export function resolveConfiguredCliInput(
 ): HunkConfigResolution {
   const repoRoot = findRepoRoot(cwd);
   const repoConfigPath = repoRoot ? join(repoRoot, ".hunk", "config.toml") : undefined;
-  const userConfigPath = globalConfigPath(env);
+  const userConfigPath = resolveGlobalConfigPath(env);
 
   let resolvedOptions: CommonOptions = {
     mode: DEFAULT_VIEW_PREFERENCES.mode,

src/core/paths.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, test } from "bun:test";
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { dirname, join } from "node:path";
+import {
+  resolveBundledHunkReviewSkillPath,
+  resolveGlobalConfigPath,
+  resolveHunkStatePath,
+} from "./paths";
+
+function createTempRoot(prefix: string) {
+  return mkdtempSync(join(tmpdir(), prefix));
+}
+
+describe("paths", () => {
+  test("resolves XDG config and state paths", () => {
+    const env = { XDG_CONFIG_HOME: "/tmp/xdg-home" } as NodeJS.ProcessEnv;
+
+    expect(resolveGlobalConfigPath(env)).toBe("/tmp/xdg-home/hunk/config.toml");
+    expect(resolveHunkStatePath(env)).toBe("/tmp/xdg-home/hunk/state.json");
+  });
+
+  test("falls back to HOME for config and state paths", () => {
+    const env = { HOME: "/tmp/home" } as NodeJS.ProcessEnv;
+
+    expect(resolveGlobalConfigPath(env)).toBe("/tmp/home/.config/hunk/config.toml");
+    expect(resolveHunkStatePath(env)).toBe("/tmp/home/.config/hunk/state.json");
+  });
+
+  test("locates the bundled Hunk review skill from source", () => {
+    const resolvedPath = resolveBundledHunkReviewSkillPath([import.meta.dir]);
+
+    expect(resolvedPath).toEndWith(join("skills", "hunk-review", "SKILL.md"));
+  });
+
+  test("locates the bundled Hunk review skill through a nested hunkdiff package", () => {
+    const tempRoot = createTempRoot("hunk-skill-path-");
+
+    try {
+      const nestedPackageRoot = join(tempRoot, "node_modules", "hunkdiff");
+      const skillPath = join(nestedPackageRoot, "skills", "hunk-review", "SKILL.md");
+      const fakeBinary = join(tempRoot, "node_modules", "hunkdiff-linux-x64", "bin", "hunk");
+
+      mkdirSync(dirname(skillPath), { recursive: true });
+      mkdirSync(dirname(fakeBinary), { recursive: true });
+      writeFileSync(skillPath, "# skill\n");
+      writeFileSync(fakeBinary, "binary\n");
+
+      expect(resolveBundledHunkReviewSkillPath([fakeBinary])).toBe(skillPath);
+    } finally {
+      rmSync(tempRoot, { recursive: true, force: true });
+    }
+  });
+});