diff --git a/README.md b/README.md
index 59501c5..bce8f2d 100644
--- a/README.md
+++ b/README.md
@@ -81,12 +81,28 @@ ghostq install
 ```
 ghostq install           set up the global post-checkout hook (core.hooksPath)
 ghostq apply [path]      link overlay files into the checkout (idempotent)
+ghostq adopt <file>...   move existing gitignored files into the overlay and link them
 ghostq status [path]     show link states and warnings without changing anything
 ghostq prune [path]      remove dangling ghostq-managed links (idempotent)
 ghostq root              print the overlay root
 ghostq uninstall         remove the hook wiring
 ```
 
+### Adopting an existing file
+
+If a personal file already exists as a real file in your checkout (instead of
+having been set up in the overlay first), `ghostq adopt <file>...` moves it
+into this repo's overlay entry and replaces it with the same kind of symlink
+`apply` would produce — one command instead of manually creating the overlay
+directory and copying the file over.
+
+Each file passed to `adopt` must already be gitignored (`adopt` never adopts a
+tracked file) and must be a real file, not a symlink or a directory — pass
+individual files; ghostq never links whole directories (symlink-each). If the
+overlay already has a file at the target path, or the checkout path is already
+a symlink pointing elsewhere, `adopt` warns and skips it rather than
+clobbering anything.
+
 ## Overlay layout
 
 Default overlay root: `${XDG_CONFIG_HOME:-~/.config}/ghostq/overlay`,
diff --git a/src/adopt.ts b/src/adopt.ts
new file mode 100644
index 0000000..1d1134e
--- /dev/null
+++ b/src/adopt.ts
@@ -0,0 +1,102 @@
+import { promises as fs } from "node:fs";
+import { dirname, join, relative, resolve } from "node:path";
+import { resolveContext } from "./context.ts";
+import { git } from "./git.ts";
+
+export type AdoptOutcome =
+  | "adopted"
+  | "already-adopted"
+  | "skipped-not-ignored"
+  | "skipped-conflict"
+  | "skipped-directory"
+  | "error";
+
+export interface AdoptReport {
+  path: string;
+  outcome: AdoptOutcome;
+  detail?: string;
+}
+
+export async function adoptFiles(paths: string[], cwd: string): Promise<AdoptReport[]> {
+  const reports: AdoptReport[] = [];
+  for (const path of paths) {
+    reports.push(await adoptOne(path, cwd));
+  }
+  return reports;
+}
+
+async function adoptOne(path: string, cwd: string): Promise<AdoptReport> {
+  const requested = resolve(cwd, path);
+
+  let st;
+  try {
+    st = await fs.lstat(requested);
+  } catch {
+    return { path, outcome: "error", detail: `no such file: ${requested}` };
+  }
+  // Directories hold committed files next to overlay links (symlink-each);
+  // adopting one wholesale would either skip its committed siblings or
+  // require a recursive walk that duplicates apply's own traversal. Reject
+  // and let the caller pass the individual gitignored files instead.
+  if (st.isDirectory()) {
+    return { path, outcome: "skipped-directory", detail: "pass individual files, not a directory" };
+  }
+
+  // ctx.root comes from `git rev-parse --show-toplevel`, which resolves
+  // symlinks in the path; resolve the parent dir the same way so `relative()`
+  // below does not produce a bogus `../..` path when cwd is reached through
+  // a symlinked ancestor (e.g. macOS's /tmp -> /private/tmp).
+  const parent = await fs.realpath(dirname(requested));
+  const abs = join(parent, requested.slice(dirname(requested).length + 1));
+
+  const res = await resolveContext(parent);
+  if (!res.ok) {
+    return { path, outcome: "error", detail: res.reason };
+  }
+  const { ctx } = res;
+
+  const rel = relative(ctx.root, abs);
+  const overlayPath = join(ctx.entryDir, rel);
+
+  const ignored = git(["check-ignore", "-q", "--", rel], ctx.root);
+  if (ignored.status !== 0) {
+    return { path, outcome: "skipped-not-ignored", detail: "not gitignored in this repo (add it to .gitignore)" };
+  }
+
+  if (st.isSymbolicLink()) {
+    const target = resolve(dirname(abs), await fs.readlink(abs));
+    if (target === resolve(overlayPath)) {
+      return { path, outcome: "already-adopted" };
+    }
+    return { path, outcome: "skipped-conflict", detail: "already a symlink pointing elsewhere; will not clobber" };
+  }
+
+  let overlayExists = true;
+  try {
+    await fs.lstat(overlayPath);
+  } catch {
+    overlayExists = false;
+  }
+  if (overlayExists) {
+    return { path, outcome: "skipped-conflict", detail: `overlay already has a file at ${overlayPath}` };
+  }
+
+  await fs.mkdir(dirname(overlayPath), { recursive: true });
+  await moveFile(abs, overlayPath);
+  await fs.symlink(overlayPath, abs);
+
+  return { path, outcome: "adopted", detail: rel };
+}
+
+async function moveFile(src: string, dst: string): Promise<void> {
+  try {
+    await fs.rename(src, dst);
+  } catch (err) {
+    // EXDEV: overlay root lives on a different filesystem than the
+    // checkout (e.g. overlay on a separate volume); rename cannot cross
+    // devices, so fall back to copy+unlink.
+    if ((err as NodeJS.ErrnoException).code !== "EXDEV") throw err;
+    await fs.copyFile(src, dst);
+    await fs.unlink(src);
+  }
+}
diff --git a/src/index.ts b/src/index.ts
index ed062e9..c32fde7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,5 @@
 #!/usr/bin/env bun
+import { type AdoptOutcome, adoptFiles } from "./adopt.ts";
 import { applyFiles, inspectFiles, pruneFiles, type FileState } from "./apply.ts";
 import { resolveContext } from "./context.ts";
 import { install, uninstall } from "./install.ts";
@@ -9,6 +10,7 @@ const USAGE = `ghostq — re-link personal, gitignored, per-repo files on clone
 Usage:
   ghostq install           set up the global post-checkout hook (core.hooksPath)
   ghostq apply [path]      link overlay files into the checkout (idempotent)
+  ghostq adopt <file>...   move existing gitignored files into the overlay and link them
   ghostq status [path]     show link states and warnings without changing anything
   ghostq prune [path]      remove dangling ghostq-managed links (idempotent)
   ghostq root              print the overlay root
@@ -57,6 +59,40 @@ async function prune(path: string): Promise<number> {
   return 0;
 }
 
+const ADOPT_NOTES: Record<AdoptOutcome, string> = {
+  adopted: "",
+  "already-adopted": "already linked into the overlay",
+  "skipped-not-ignored": "not gitignored in this repo (add it to .gitignore)",
+  "skipped-conflict": "",
+  "skipped-directory": "pass individual files, not a directory",
+  error: "",
+};
+
+async function adopt(paths: string[]): Promise<number> {
+  const reports = await adoptFiles(paths, process.cwd());
+  let failed = false;
+  for (const { path, outcome, detail } of reports) {
+    switch (outcome) {
+      case "adopted":
+        console.log(`adopted  ${path}${detail ? ` -> ${detail}` : ""}`);
+        break;
+      case "already-adopted":
+        console.log(`ghostq: ${path}: ${ADOPT_NOTES[outcome]}`);
+        break;
+      case "error":
+        console.error(`ghostq: ${path}: ${detail}`);
+        failed = true;
+        break;
+      default: {
+        const note = detail || ADOPT_NOTES[outcome];
+        console.error(`ghostq: skip ${path}: ${note}`);
+        break;
+      }
+    }
+  }
+  return failed ? 1 : 0;
+}
+
 const STATE_NOTES: Record<FileState, string> = {
   linked: "",
   missing: "run `ghostq apply`",
@@ -100,6 +136,12 @@ async function main(): Promise<number> {
       return uninstall();
     case "apply":
       return apply(rest[0] ?? process.cwd());
+    case "adopt":
+      if (rest.length === 0) {
+        console.error("ghostq: adopt requires at least one file");
+        return 1;
+      }
+      return adopt(rest);
     case "status":
       return status(rest[0] ?? process.cwd());
     case "prune":
diff --git a/test/adopt.test.ts b/test/adopt.test.ts
new file mode 100644
index 0000000..e6eeeb2
--- /dev/null
+++ b/test/adopt.test.ts
@@ -0,0 +1,124 @@
+import { afterEach, beforeEach, describe, expect, test } from "bun:test";
+import { promises as fs } from "node:fs";
+import { join } from "node:path";
+import { adoptFiles } from "../src/adopt.ts";
+import { applyFiles } from "../src/apply.ts";
+import { resolveContext } from "../src/context.ts";
+import { makeRepo, makeTmpDir, writeOverlayEntry } from "./helpers.ts";
+
+const IDENTITY = "github.com/testuser/testrepo";
+const REMOTE = "https://github.com/testuser/testrepo.git";
+
+let tmp: string;
+let repo: string;
+let savedRoot: string | undefined;
+
+beforeEach(async () => {
+  tmp = await makeTmpDir("ghostq-adopt");
+  savedRoot = process.env.GHOSTQ_ROOT;
+  process.env.GHOSTQ_ROOT = join(tmp, "overlay");
+  repo = join(tmp, "repo");
+  await makeRepo(
+    repo,
+    {
+      ".gitignore": ".env.local\n.claude/personal.md\n",
+      ".claude/settings.json": "{ \"committed\": true }\n",
+      "README.md": "hello\n",
+    },
+    { remote: REMOTE },
+  );
+});
+
+afterEach(async () => {
+  if (savedRoot === undefined) delete process.env.GHOSTQ_ROOT;
+  else process.env.GHOSTQ_ROOT = savedRoot;
+  await fs.rm(tmp, { recursive: true, force: true });
+});
+
+async function contextFor(dir: string) {
+  const res = await resolveContext(dir);
+  if (!res.ok) throw new Error(res.reason);
+  return res.ctx;
+}
+
+describe("ghostq adopt", () => {
+  test("moves a gitignored real file into the overlay and replaces it with a symlink", async () => {
+    await fs.writeFile(join(repo, ".env.local"), "SECRET=1\n");
+
+    const [report] = await adoptFiles([".env.local"], repo);
+
+    expect(report!.outcome).toBe("adopted");
+    const overlayFile = join(process.env.GHOSTQ_ROOT!, IDENTITY, ".env.local");
+    expect(await fs.readFile(overlayFile, "utf8")).toBe("SECRET=1\n");
+
+    const link = join(repo, ".env.local");
+    expect((await fs.lstat(link)).isSymbolicLink()).toBe(true);
+    expect(await fs.readlink(link)).toBe(overlayFile);
+    expect(await fs.readFile(link, "utf8")).toBe("SECRET=1\n");
+  });
+
+  test("after adopt, applyFiles reports the file as already linked", async () => {
+    await fs.writeFile(join(repo, ".env.local"), "SECRET=1\n");
+    await adoptFiles([".env.local"], repo);
+
+    const report = await applyFiles(await contextFor(repo));
+
+    expect(report.alreadyLinked).toEqual([".env.local"]);
+    expect(report.linked).toEqual([]);
+    expect(report.conflicts).toEqual([]);
+  });
+
+  test("a tracked (non-ignored) file is skipped and left as a real file", async () => {
+    const [report] = await adoptFiles(["README.md"], repo);
+
+    expect(report!.outcome).toBe("skipped-not-ignored");
+    const st = await fs.lstat(join(repo, "README.md"));
+    expect(st.isSymbolicLink()).toBe(false);
+    expect(await fs.readFile(join(repo, "README.md"), "utf8")).toBe("hello\n");
+  });
+
+  test("a file already symlinked into the overlay is reported as already-adopted", async () => {
+    await fs.writeFile(join(repo, ".env.local"), "SECRET=1\n");
+    await adoptFiles([".env.local"], repo);
+
+    const [second] = await adoptFiles([".env.local"], repo);
+
+    expect(second!.outcome).toBe("already-adopted");
+    const link = join(repo, ".env.local");
+    expect((await fs.lstat(link)).isSymbolicLink()).toBe(true);
+  });
+
+  test("adopting is skipped when an overlay file already exists at the target", async () => {
+    await writeOverlayEntry(process.env.GHOSTQ_ROOT!, IDENTITY, {
+      ".env.local": "overlay version\n",
+    });
+    await fs.writeFile(join(repo, ".env.local"), "local version\n");
+
+    const [report] = await adoptFiles([".env.local"], repo);
+
+    expect(report!.outcome).toBe("skipped-conflict");
+    expect(await fs.readFile(join(repo, ".env.local"), "utf8")).toBe("local version\n");
+    expect((await fs.lstat(join(repo, ".env.local"))).isSymbolicLink()).toBe(false);
+    expect(await fs.readFile(join(process.env.GHOSTQ_ROOT!, IDENTITY, ".env.local"), "utf8")).toBe(
+      "overlay version\n",
+    );
+  });
+
+  test("a symlink pointing somewhere other than the overlay is skipped, not clobbered", async () => {
+    const elsewhere = join(tmp, "elsewhere.txt");
+    await fs.writeFile(elsewhere, "not overlay content\n");
+    await fs.symlink(elsewhere, join(repo, ".env.local"));
+
+    const [report] = await adoptFiles([".env.local"], repo);
+
+    expect(report!.outcome).toBe("skipped-conflict");
+    expect(await fs.readlink(join(repo, ".env.local"))).toBe(elsewhere);
+  });
+
+  test("passing a directory is rejected cleanly", async () => {
+    const [report] = await adoptFiles([".claude"], repo);
+
+    expect(report!.outcome).toBe("skipped-directory");
+    expect((await fs.lstat(join(repo, ".claude"))).isDirectory()).toBe(true);
+  });
+});