@@ -78,6 +78,71 @@ jobs:
           uv run --frozen graphify --help
           uv run --frozen graphify install
 
+  omp-bridge:
+    # tests/omp.test.ts drives the real OMP extension: bun resolves the
+    # path-utils helpers it imports from the pinned @oh-my-pi/pi-coding-agent
+    # devDependency in graphify/omp/ (the only package the host provides;
+    # graphify/omp/index.ts vendors isReadableUrlPath locally instead of
+    # importing it from @oh-my-pi/pi-tui, which the host never resolves), and
+    # the policy assertions run against the real installed Python CLI, so
+    # this job needs both toolchains.
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v8.1.0
+        with:
+          python-version: "3.12"
+
+      - name: Install bun
+        uses: oven-sh/setup-bun@v2
+
+      - name: Install dependencies
+        run: uv sync --frozen
+
+      - name: Install OMP extension dependencies
+        run: bun install --frozen-lockfile
+        working-directory: graphify/omp
+
+      - name: Run OMP bridge tests
+        run: GRAPHIFY_TEST_CLI=$PWD/.venv/bin/graphify bun test tests/omp.test.ts
+
+      - name: Check for upstream symbol moves (advisory, no execution)
+        # The frozen run above only proves the bridge works against the
+        # exact pinned version. Upstream OMP has moved exported symbols
+        # between minor releases before (isReadableUrlPath moved from
+        # pi-coding-agent to pi-tui) without the frozen lockfile ever seeing
+        # it; index.ts now vendors that predicate locally instead of
+        # tracking whichever package currently exports it. This step used
+        # to install @latest AND execute the whole suite against it --
+        # unpinned, mutable third-party code running on every CI invocation.
+        # It now only downloads the published package (--ignore-scripts:
+        # no install hooks run) and statically compares index.ts's imported
+        # path-utils symbols against that file's declared exports as plain
+        # text -- the downloaded code is never imported or executed, but a
+        # future symbol move still surfaces here.
+        # continue-on-error: an unrelated upstream release must not block a
+        # merge; the frozen run above stays the blocking gate.
+        continue-on-error: true
+        run: |
+          bun add --cwd graphify/omp -d @oh-my-pi/pi-coding-agent@latest --ignore-scripts
+          bun -e '
+          const fs = require("node:fs");
+          const index = fs.readFileSync("graphify/omp/index.ts", "utf8");
+          const block = index.match(/import\s*{([^}]+)}\s*from\s*"@oh-my-pi\/pi-coding-agent\/tools\/path-utils"/);
+          if (!block) throw new Error("no path-utils import block found in index.ts");
+          const imported = block[1].split(",").map((s) => s.trim()).filter(Boolean);
+          const source = fs.readFileSync("graphify/omp/node_modules/@oh-my-pi/pi-coding-agent/src/tools/path-utils.ts", "utf8");
+          const exported = new Set([...source.matchAll(/^export\s+(?:async\s+function|function)\s+(\w+)/gm)].map((m) => m[1]));
+          const missing = imported.filter((name) => !exported.has(name));
+          if (missing.length) {
+            console.error(`@oh-my-pi/pi-coding-agent@latest no longer exports: ${missing.join(", ")}`);
+            process.exit(1);
+          }
+          console.log(`ok: every imported symbol is exported by @latest (${imported.join(", ")})`);
+          '
+
   security-scan:
     # The dev deps include bandit and pip-audit. Run them in CI so a new
     # HIGH-severity finding or vulnerable dependency is caught on the PR that
 
@@ -40,3 +40,9 @@ paper/
 
 # macOS Finder metadata
 .DS_Store
+
+# OMP extension test dependency tree (graphify/omp)
+graphify/omp/node_modules/
+
+# Local symlink for the root-level bun tests (temporary, per AGENTS.md)
+/node_modules
@@ -103,6 +103,7 @@ Full release notes with details on each version: [GitHub Releases](https://githu
 
 ## 0.9.58 (2026-09-10)
 
+- Feature: ship a native Oh My Pi guard package with `graphify omp install`; reuse the installed hook-guard policy for bounded tool-call denials and per-call guidance delivered with each tool result as a leading `<system-reminder source="graphify">` block, matching how Claude Code labels PreToolUse context, without building indexes.
 - Fix: a call to a Python function defined nested inside another function now resolves to that inner definition per lexical scope, instead of leaking to a same-named function elsewhere; direct recursion is preserved as a self-loop (#3410, thanks @hopstreax).
 - Fix: submodule imports inside a PEP 420 namespace package (a directory with no `__init__.py`) now resolve to the target module instead of being dropped (#3429, thanks @flaukowski).
 - Fix: a bare-name import of a module sitting next to the importing file (a flat script dir with no package) now resolves to that sibling — matching CPython's `sys.path[0]` behavior — without over-resolving a genuine third-party name (#3430, thanks @hopstreax).
 
@@ -232,6 +232,7 @@ for example `graphify claude install --project` or `graphify codex install --pro
 | Agent Skills (cross-framework) | `graphify install --platform agents` (alias `--platform skills`) |
 | Kiro IDE/CLI | `graphify kiro install` |
 | Pi coding agent | `graphify install --platform pi` |
+| Oh My Pi (native guard) | `graphify omp install` |
 | Cursor | `graphify cursor install` |
 | Devin CLI | `graphify devin install` |
 | Google Antigravity | `graphify antigravity install` |
@@ -305,6 +306,7 @@ Run this once in your project after building a graph:
 | Agent Skills (cross-framework) | `graphify agents install` (alias `graphify skills install`) |
 | Kiro IDE/CLI | `graphify kiro install` |
 | Pi coding agent | `graphify pi install` |
+| Oh My Pi (native guard) | `graphify omp install` |
 | Devin CLI | `graphify devin install` |
 | Google Antigravity | `graphify antigravity install` |
 
@@ -323,7 +325,55 @@ This writes a small config file that tells your assistant to consult the knowled
 
 **Cursor** writes `.cursor/rules/graphify.mdc` with `alwaysApply: true`, so Cursor includes it in every conversation automatically, no hook needed.
 
-To remove graphify from all platforms at once: `graphify uninstall` (add `--purge` to also delete `graphify-out/`). Or use the per-platform command (e.g. `graphify claude uninstall`).
+### Oh My Pi (OMP) native guard
+
+Install Graphify into a persistent environment with `uv tool install graphifyy` or
+`pipx install graphifyy`, and install OMP separately. Then run:
+
+```bash
+graphify omp install
+```
+
+This delegates to OMP's supported `omp plugin install <local-package-directory>`
+route. The Python wheel and source distribution contain `graphify/omp/package.json`
+with explicit `omp.extensions` and its TypeScript entry point; OMP links that
+directory and discovers the extension. No npm adapter package, shell hook, Pi API
+shim, or hand-edited OMP settings are required. `graphify omp path` prints the same
+directory for manual `omp plugin install` or one-session `omp -e` use. Restart OMP
+after installing/upgrading, and rerun the installer if the Python environment
+moves. Do not link from an ephemeral `uvx` environment.
+
+Before native `read`, `glob`, `grep`, and search-style `bash` calls, the extension
+runs the installed `graphify hook-guard read|search` CLI. The existing Python
+policy owns fresh/stale graph decisions and strict-mode denials: start OMP with
+`GRAPHIFY_HOOK_STRICT=1` to enable its once-per-session indexed-read block.
+Denials become OMP `block`/`reason`; each qualifying call carries its own
+guidance, appended to that call's persisted tool result (Claude
+`PreToolUse` additionalContext parity), and pending deliveries are cleared for
+each new user run and session navigation. In-flight hooks
+are cancelled on these boundaries. No graph is created or updated automatically.
+The guard package intentionally declares no skills; the existing cross-framework
+skill remains available separately through `graphify agents install`.
+
+Only local filesystem targets are inspected, using OMP's selector/path helpers.
+URLs and internal resources are excluded. Hooks require an installed `graphify`
+on an absolute PATH entry outside the project (including outside a project-local
+virtualenv); there is no project Python or command fallback. Each native tool call
+has a 256 KiB JSON-input cap, a 64 KiB output cap and a two-second subprocess budget
+with forced termination. Missing commands, invalid output and failures fail open.
+
+The extension checks `ctx.isProjectTrusted()` before execution and context
+injection, but **current OMP exposes this compatibility method as always true**:
+it is not an enforced trust sandbox. Enable this integration only in projects you
+trust. The lifecycle contract is based on OMP integration commit
+`6aef0e8ad51b3bc5ea7a5f2a255c3d48e4c5af72`; the `18.1.17` version string alone
+does not establish those lifecycle fixes.
+
+Remove this host-managed link with `omp plugin uninstall graphify-omp` **before**
+uninstalling the Python package. `graphify uninstall` handles Graphify-managed
+platform files, not OMP's plugin registry.
+
+To remove Graphify-managed platform files at once: `graphify uninstall` (add `--purge` to also delete `graphify-out/`). Or use the per-platform command (e.g. `graphify claude uninstall`). OMP links are removed separately as described above.
 
 ---
 
@@ -764,6 +814,9 @@ graphify kiro install               # .kiro/skills/ + .kiro/steering/graphify.md
 graphify kiro uninstall
 graphify pi install                # skill file (Pi coding agent)
 graphify pi uninstall
+graphify omp install               # native guard package, registered by OMP
+graphify omp path                  # shipped package directory for manual linking
+omp plugin uninstall graphify-omp  # remove the host-managed link
 graphify devin install             # skill file + .windsurf/rules/graphify.md (Devin CLI)
 graphify devin uninstall
 graphify antigravity install       # .agents/rules + .agents/workflows (Google Antigravity)
 
@@ -572,7 +572,7 @@ def _run_cli() -> None:
     # Skip during install/uninstall (hook writes trigger a fresh check anyway).
     # Skip during hook-check — it runs on every editor tool use and must be silent.
     # Deduplicate paths so platforms sharing the same install dir don't warn twice.
-    _silent_cmds = {"install", "uninstall", "hook-check", "hook-guard"}
+    _silent_cmds = {"install", "uninstall", "hook-check", "hook-guard", "omp"}
     if not any(arg in _silent_cmds for arg in sys.argv):
         # Resolve each platform's real user-scope destination so per-platform
         # overrides (gemini, opencode, devin, antigravity, amp) check the dir
@@ -591,6 +591,7 @@ def _run_cli() -> None:
         print("  install [--platform P]  copy skill to platform config dir (claude|windows|codebuddy|codex|opencode|aider|amp|agents|claw|droid|trae|trae-cn|gemini|cursor|antigravity|hermes|kiro|pi|devin)")
         print("  uninstall               remove graphify from all detected platforms in one shot")
         print("    --purge                 also delete graphify-out/ directory")
+        print("  omp [install|path]      install the native Oh My Pi guard, or print its package path")
         print("  path \"A\" \"B\"            shortest path between two nodes in graph.json")
         print("    --graph <path>          path to graph.json (default graphify-out/graph.json)")
         print("  explain \"X\"             plain-language explanation of a node and its neighbors")
 
@@ -13,6 +13,7 @@
 import time
 from graphify.paths import GRAPHIFY_OUT as _GRAPHIFY_OUT
 from pathlib import Path, PurePosixPath, PureWindowsPath
+from urllib.parse import unquote, urlsplit
 
 
 _SEARCH_NUDGE = json.dumps({
@@ -894,10 +895,26 @@ def _run_hook_guard(kind: str, strict: bool = False) -> None:
             if explicit:
                 in_project = False
                 for v in explicit:
+                    v = _normalize_hook_path(v)
+                    # A bare www.host/... value is remote only when nothing
+                    # identically named exists locally, mirroring OMP's own
+                    # "an existing local path wins over URL" precedence
+                    # (resolveToolSearchScope). Decided here, not inside
+                    # _is_cwd_relative, which has no cwd/root of its own.
+                    if _is_external_www_target(v, root):
+                        continue
                     p = Path(v)
                     if _is_cwd_relative(v):
                         in_project = True  # relative -> anchored at cwd == in project
                         break
+                    # _is_cwd_relative already rejects a *whole-value*
+                    # scheme://... prefix above (a rootless URL never reaches
+                    # here). This catches the same URL after some upstream
+                    # host has already glued it onto an absolute prefix
+                    # (`<root>/local:/x`), which looks exactly like a real
+                    # file to the containment check below.
+                    if _has_embedded_url_scheme_segment(v):
+                        continue
                     try:
                         p.resolve().relative_to(root)
                         in_project = True
@@ -942,6 +959,73 @@ def _run_hook_guard(kind: str, strict: bool = False) -> None:
         pass
 
 
+_URL_SCHEME_PREFIX_RE = re.compile(r"^[a-zA-Z][a-zA-Z0-9+.-]*://")
+_URL_SCHEME_SEGMENT_RE = re.compile(r"^[a-zA-Z][a-zA-Z0-9+.-]*:$")
+_FILE_URL_RE = re.compile(r"^file://", re.IGNORECASE)
+_WWW_HOST_RE = re.compile(r"^www\.", re.IGNORECASE)
+
+
+def _normalize_hook_path(value: str) -> str:
+    r"""Trim padding whitespace and a matching pair of outer double quotes,
+    then strip a *local* leading ``file://`` scheme down to the local path
+    it names.
+
+    Mirrors what OMP's own path pipeline already does to a raw tool argument
+    before a hook would ever see it: ``normalizePathLikeInput`` (trim +
+    de-quote) and ``file://`` -> ``url.fileURLToPath`` (its own
+    ``strictExternalUrlRe`` deliberately omits ``file``, routing it through
+    the ordinary local-file path instead of the external-URL one). The guard
+    must classify identical text identically whether or not a given host
+    bothered to normalize it first -- a classifier that only agrees with its
+    own host after trimming/de-quoting is exactly the kind of gap a prior
+    review flagged.
+
+    Per RFC 8089, a ``file://`` URL is local only when its authority is
+    empty (``file:///path``) or ``localhost``; Node's own
+    ``url.fileURLToPath`` enforces exactly this, throwing
+    ``ERR_INVALID_FILE_URL_HOST`` for any other host. Any other authority
+    names a *remote* host, not a local path -- reducing it here would
+    discard the host and let ``file://evil.com/<in-project path>`` alias a
+    real local file, so it is left untouched for ``_is_foreign_url_scheme``
+    to classify instead.
+    """
+    value = value.strip()
+    if len(value) > 1 and value[0] == value[-1] == '"':
+        value = value[1:-1]
+    if _FILE_URL_RE.match(value):
+        split = urlsplit(value)
+        if split.hostname and split.hostname.lower() != "localhost":
+            return value
+        path = unquote(split.path) or "/"
+        # file:///C:/proj/a.py -> C:/proj/a.py: drop the URL's extra root
+        # slash in front of a Windows drive letter.
+        if os.name == "nt" and re.match(r"^/[A-Za-z]:", path):
+            path = path[1:]
+        return path
+    return value
+
+
+def _is_foreign_url_scheme(value: str) -> bool:
+    """Whether *value* is itself a ``scheme://...`` value -- everything
+    except a *local* ``file://`` (empty or ``localhost`` authority, RFC
+    8089), which ``_normalize_hook_path`` has already reduced to a plain
+    local path by the time this runs, so it never matches here. A
+    ``file://`` with any other authority is NOT reduced by
+    ``_normalize_hook_path`` and so matches here like any other foreign
+    scheme, naming a remote host rather than a local file.
+
+    Deliberately does not enumerate OMP's (or any other harness's) internal
+    scheme allow-list (``local://``, ``artifact://``, ...): this guard is
+    embedded by multiple hosts (#522), and hard-coding one of them would
+    silently stop matching the day that host adds a scheme. Any scheme this
+    function doesn't specifically know to be local -- only a local
+    ``file://`` is -- is treated as not-a-local-source-file: a missed nudge
+    on a remote URL is a far safer wrong answer than a wrong nudge on an
+    unrelated file.
+    """
+    return bool(_URL_SCHEME_PREFIX_RE.match(value))
+
+
 def _is_cwd_relative(value: str) -> bool:
     r"""Whether *value* is anchored at the current working directory.
 
@@ -964,11 +1048,63 @@ def _is_cwd_relative(value: str) -> bool:
     so ``paths.is_absolute_any_platform`` (for stored, portable paths) is
     deliberately not used. On POSIX ``root`` is set exactly when the path is
     absolute and ``drive`` is always empty, so this is unchanged there.
+
+    A URL is rootless and driveless by that exact same test -- ``https://x``
+    and ``myscheme://x`` have no ``root`` and no ``drive`` in either flavour
+    -- so without checking the scheme first, this rule alone short-circuits
+    the caller straight to "in project" for a value that names no filesystem
+    path at all (the bug this guards against, #522 follow-up).
+    ``_normalize_hook_path`` and ``_is_foreign_url_scheme`` reject that
+    shape, and strip a ``file://`` wrapper down to its local path, before
+    the root/drive test below ever runs.
     """
+    value = _normalize_hook_path(value)
+    if _is_foreign_url_scheme(value):
+        return False
     pure = PureWindowsPath(value) if os.name == "nt" else PurePosixPath(value)
     return not pure.root and not pure.drive
 
 
+def _has_embedded_url_scheme_segment(value: str) -> bool:
+    """Whether an already-absolute *value* still carries a collapsed
+    ``scheme://`` marker as one of its OWN path segments, e.g.
+    ``<root>/local:/x`` -- what a naive host-side path-join leaves behind
+    when it glues a rootless ``scheme://...`` value onto a root/cwd prefix
+    instead of routing it through a URL handler, defeating the whole-value
+    check in ``_is_cwd_relative`` above.
+
+    Only meaningful once a value is already known to have a root or drive
+    (``_is_cwd_relative`` returned ``False``): the leading component IS that
+    root/drive marker, so it is skipped here on purpose -- a genuinely
+    relative, colon-bearing POSIX filename like ``C:/proj/a.py`` never
+    reaches this function at all (it takes the cwd-relative shortcut above
+    and stays in-project, matching POSIX semantics where a colon has no
+    special meaning).
+    """
+    pure = PureWindowsPath(value) if os.name == "nt" else PurePosixPath(value)
+    parts = pure.parts[1:] if (pure.root or pure.drive) else pure.parts
+    return any(_URL_SCHEME_SEGMENT_RE.match(part) for part in parts)
+
+
+def _is_external_www_target(value: str, root: "Path") -> bool:
+    """Whether *value* is a bare ``www.host/...`` external-read shape with no
+    identically named local file to override it.
+
+    Mirrors OMP's own ``isReadableUrlPath``/``resolveToolSearchScope``
+    precedence: a ``www.`` value carries no ``://`` at all, so no scheme rule
+    catches it, and it is remote only when nothing local shares its exact
+    name ("an existing local path wins over URL"). A project that genuinely
+    has a top-level path named e.g. ``www.example.com`` stays classified as
+    local; only the common case -- no such path -- is treated as external.
+    """
+    if not _WWW_HOST_RE.match(value):
+        return False
+    try:
+        return not (root / value).exists()
+    except OSError:
+        return False
+
+
 def _target_is_indexed(file_path: str, root: "Path") -> bool:
     """Guard the strict deny: only block a read of a file the graph actually indexes.
     Reads manifest.json (cheap, capped); on any doubt (missing/corrupt/oversized