diff --git a/scripts/remove_openspec.py b/scripts/remove_openspec.py
new file mode 100644
index 00000000..5b5fae36
--- /dev/null
+++ b/scripts/remove_openspec.py
@@ -0,0 +1,296 @@
+#!/usr/bin/env python3
+"""
+Remove OpenSpec configuration files from a project.
+
+This script deletes the core OpenSpec directory plus integration files for
+Codex and project-level agent commands (Claude Code, Cursor, OpenCode, Factory
+Droid, Windsurf, Kilo Code, Amazon Q, GitHub Copilot). For AGENTS.md and
+CLAUDE.md it removes only the managed OpenSpec block so custom instructions
+remain intact. Provide the target project path as the first argument (quotes
+are supported for paths that contain spaces). Use --instructions-only to limit
+cleanup to AGENTS.md and CLAUDE.md without touching other OpenSpec assets.
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import shutil
+import sys
+from pathlib import Path
+from typing import Iterable, Tuple, Literal
+
+
+def remove_path(target: Path) -> bool:
+    """Remove a file or directory if it exists, returning True when deleted."""
+    try:
+        if not target.exists():
+            return False
+        if target.is_dir() and not target.is_symlink():
+            shutil.rmtree(target)
+        else:
+            target.unlink()
+        return True
+    except Exception as exc:  # pragma: no cover - best-effort cleanup
+        print(f"Failed to remove {target}: {exc}", file=sys.stderr)
+        return False
+
+
+def remove_many(paths: Iterable[Path]) -> Tuple[int, int]:
+    """Attempt to remove multiple paths; return (removed, missing) counts."""
+    removed = 0
+    missing = 0
+    for file_path in paths:
+        if remove_path(file_path):
+            print(f"Removed {file_path}")
+            removed += 1
+        else:
+            print(f"Skipped (missing): {file_path}")
+            missing += 1
+    return removed, missing
+
+
+def build_project_targets(project_root: Path) -> Iterable[Path]:
+    """Yield project-scoped paths that should be removed."""
+    openspec_dir = project_root / "openspec"
+    claude_commands = [
+        project_root
+        / ".claude"
+        / "commands"
+        / "openspec"
+        / f"{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    factory_commands = [
+        project_root / ".factory" / "commands" / f"openspec-{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    cursor_commands = [
+        project_root / ".cursor" / "commands" / f"openspec-{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    opencode_commands = [
+        project_root / ".opencode" / "commands" / f"openspec-{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    windsurf_commands = [
+        project_root / ".windsurf" / "workflows" / f"openspec-{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    kilocode_commands = [
+        project_root / ".kilocode" / "workflows" / f"openspec-{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    amazonq_commands = [
+        project_root / ".amazonq" / "prompts" / f"openspec-{name}.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+    github_copilot_commands = [
+        project_root / ".github" / "prompts" / f"openspec-{name}.prompt.md"
+        for name in ("proposal", "apply", "archive")
+    ]
+
+    for target in [
+        openspec_dir,
+        *claude_commands,
+        *factory_commands,
+        *cursor_commands,
+        *opencode_commands,
+        *windsurf_commands,
+        *kilocode_commands,
+        *amazonq_commands,
+        *github_copilot_commands,
+    ]:
+        yield target
+
+
+def build_codex_targets(prompts_dir: Path) -> Iterable[Path]:
+    """Yield Codex prompt files that should be removed."""
+    for name in ("proposal", "apply", "archive"):
+        yield prompts_dir / f"openspec-{name}.md"
+
+
+def prune_empty(paths: Iterable[Path]) -> None:
+    """Remove empty directories, ignoring errors."""
+    for dir_path in paths:
+        try:
+            if dir_path.exists() and dir_path.is_dir():
+                # Check whether directory is empty before removing.
+                if not any(dir_path.iterdir()):
+                    dir_path.rmdir()
+                    print(f"Removed empty directory {dir_path}")
+        except Exception as exc:  # pragma: no cover - best-effort cleanup
+            print(f"Could not prune {dir_path}: {exc}", file=sys.stderr)
+
+
+def parse_args(argv: Iterable[str]) -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description="Remove OpenSpec files from a project."
+    )
+    parser.add_argument(
+        "project_path",
+        help="Path to the project that contains OpenSpec files.",
+    )
+    parser.add_argument(
+        "--instructions-only",
+        action="store_true",
+        help="Only remove OpenSpec managed blocks from AGENTS.md and CLAUDE.md.",
+    )
+    return parser.parse_args(argv)
+
+
+def strip_managed_block(file_path: Path) -> Literal["missing", "no_marker", "stripped", "deleted", "incomplete"]:
+    """Remove the OpenSpec managed block from a file, preserving custom content."""
+    if not file_path.exists() or not file_path.is_file():
+        return "missing"
+
+    try:
+        content = file_path.read_text(encoding="utf-8")
+    except OSError as exc:  # pragma: no cover - best-effort cleanup
+        print(f"Failed to read {file_path}: {exc}", file=sys.stderr)
+        return "missing"
+
+    start_marker = "<!-- OPENSPEC:START -->"
+    end_marker = "<!-- OPENSPEC:END -->"
+    if start_marker not in content or end_marker not in content:
+        return "no_marker"
+
+    lines = content.splitlines()
+    kept_lines = []
+    inside = False
+    removed = False
+
+    for line in lines:
+        start = start_marker in line
+        end = end_marker in line
+
+        if start and end:
+            removed = True
+            inside = False
+            continue
+
+        if start:
+            inside = True
+            removed = True
+            continue
+
+        if inside:
+            if end:
+                inside = False
+            continue
+
+        if end:
+            # Encountered end marker without matching start.
+            return "incomplete"
+
+        kept_lines.append(line)
+
+    if inside:
+        # Unmatched start marker; don't modify the file.
+        return "incomplete"
+
+    if not removed:
+        return "no_marker"
+
+    # Trim leading/trailing blank lines introduced by removal.
+    while kept_lines and not kept_lines[0].strip():
+        kept_lines.pop(0)
+    while kept_lines and not kept_lines[-1].strip():
+        kept_lines.pop()
+
+    if kept_lines:
+        new_content = "\n".join(kept_lines) + "\n"
+        try:
+            file_path.write_text(new_content, encoding="utf-8")
+        except OSError as exc:  # pragma: no cover - best-effort cleanup
+            print(f"Failed to write {file_path}: {exc}", file=sys.stderr)
+            return "incomplete"
+        return "stripped"
+
+    try:
+        file_path.unlink()
+    except OSError as exc:  # pragma: no cover - best-effort cleanup
+        print(f"Failed to delete {file_path}: {exc}", file=sys.stderr)
+        return "incomplete"
+    return "deleted"
+
+
+def cleanup_instruction_file(file_path: Path) -> Literal["missing", "no_marker", "stripped", "deleted", "incomplete"]:
+    """Surgically remove the managed block from instruction files."""
+    result = strip_managed_block(file_path)
+    if result == "missing":
+        print(f"Skipped (missing): {file_path}")
+    elif result == "no_marker":
+        print(f"No OpenSpec block found in {file_path}")
+    elif result == "stripped":
+        print(f"Removed OpenSpec block from {file_path}")
+    elif result == "deleted":
+        print(f"Removed OpenSpec block and deleted empty file {file_path}")
+    elif result == "incomplete":
+        print(f"Could not fully remove block in {file_path}; markers may be unmatched.")
+    return result
+
+
+def main(argv: Iterable[str]) -> int:
+    args = parse_args(argv)
+    project_root = Path(args.project_path).expanduser().resolve()
+
+    if not project_root.exists():
+        print(f"Project path does not exist: {project_root}", file=sys.stderr)
+        return 1
+    if not project_root.is_dir():
+        print(f"Project path is not a directory: {project_root}", file=sys.stderr)
+        return 1
+
+    print(f"Removing OpenSpec files from {project_root}")
+
+    instruction_results = [
+        cleanup_instruction_file(project_root / "AGENTS.md"),
+        cleanup_instruction_file(project_root / "CLAUDE.md"),
+    ]
+    stripped_count = sum(result in {"stripped", "deleted"} for result in instruction_results)
+
+    if args.instructions_only:
+        print(f"Cleanup complete. Updated {stripped_count} instruction file(s).")
+        return 0
+
+    project_removed, _ = remove_many(build_project_targets(project_root))
+
+    # Clean up Codex prompt files
+    codex_home = Path(os.environ.get("CODEX_HOME") or Path.home() / ".codex")
+    prompts_dir = codex_home / "prompts"
+    codex_removed, _ = remove_many(build_codex_targets(prompts_dir))
+
+    # Attempt to prune empty directories created for integrations.
+    prune_empty(
+        [
+            prompts_dir,
+            project_root / ".claude" / "commands" / "openspec",
+            project_root / ".claude" / "commands",
+            project_root / ".claude",
+            project_root / ".factory" / "commands",
+            project_root / ".factory",
+            project_root / ".cursor" / "commands",
+            project_root / ".cursor",
+            project_root / ".opencode" / "commands",
+            project_root / ".opencode",
+            project_root / ".windsurf" / "workflows",
+            project_root / ".windsurf",
+            project_root / ".kilocode" / "workflows",
+            project_root / ".kilocode",
+            project_root / ".amazonq" / "prompts",
+            project_root / ".amazonq",
+            project_root / ".github" / "prompts",
+        ]
+    )
+
+    print(
+        f"Cleanup complete. Removed {project_removed} project item(s), "
+        f"{codex_removed} Codex item(s), and updated {stripped_count} instruction file(s)."
+    )
+    print("You may manually remove any remaining empty folders if desired.")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))