diff --git a/omnigent/claude_native_forwarder.py b/omnigent/claude_native_forwarder.py
index 2d858709cb..b364cb7eb1 100644
--- a/omnigent/claude_native_forwarder.py
+++ b/omnigent/claude_native_forwarder.py
@@ -854,6 +854,7 @@ async def forward_claude_transcript_to_session(
     poll_interval_s: float = _DEFAULT_POLL_INTERVAL_S,
     auth: httpx.Auth | None = None,
     skip_user_messages: bool = False,
+    start_at_offset: int | None = None,
 ) -> None:
     """
     Tail Claude's JSONL transcript and mirror semantic items into AP.
@@ -875,6 +876,12 @@ async def forward_claude_transcript_to_session(
     :param start_at_end: When ``True`` and no prior forward cursor
         exists, start from the current transcript end. This is used
         for reattach so old transcript lines are not duplicated.
+        Ignored when *start_at_offset* is set.
+    :param start_at_offset: Byte length of a resume prefix this launch
+        synthesized, e.g. ``5920``. Preferred over *start_at_end* on the
+        cold-resume path: the exact prefix is known before launch, where a
+        live end-offset measured after Claude boots can skip a prompt the
+        executor injected in the meantime.
     :param poll_interval_s: Seconds between transcript polls.
     :param auth: Optional httpx Auth that mints a fresh bearer token
         per request, e.g. ``_server_auth(profile)`` for a Databricks
@@ -1040,6 +1047,7 @@ async def forward_claude_transcript_to_session(
                         transcript_path=transcript_path,
                         start_at_end=start_at_end,
                         session_id=current_session_id,
+                        start_at_offset=start_at_offset,
                     )
                     # Forward streamed deltas BEFORE the transcript items so a
                     # message's live chunks (incl. its ``final`` chunk) always
@@ -2056,6 +2064,7 @@ async def supervise_forwarder(
     poll_interval_s: float = _DEFAULT_POLL_INTERVAL_S,
     auth: httpx.Auth | None = None,
     skip_user_messages: bool = False,
+    start_at_offset: int | None = None,
 ) -> None:
     """
     Run :func:`forward_claude_transcript_to_session` under a restart supervisor.
@@ -2092,6 +2101,9 @@ async def supervise_forwarder(
     :param agent_name: Agent/model name to stamp on mirrored output.
     :param start_at_end: When ``True`` and no prior forward cursor
         exists, start from the current transcript end.
+    :param start_at_offset: Byte length of a resume prefix this launch
+        synthesized. Forwarded verbatim; see
+        :func:`forward_claude_transcript_to_session`.
     :param poll_interval_s: Seconds between transcript polls inside
         the forwarder loop. Forwarded verbatim.
     :param auth: Optional httpx Auth that mints a fresh bearer token
@@ -2114,6 +2126,7 @@ async def supervise_forwarder(
                 poll_interval_s=poll_interval_s,
                 auth=auth,
                 skip_user_messages=skip_user_messages,
+                start_at_offset=start_at_offset,
             )
             # The forwarder loop is ``while True`` and is not expected
             # to return normally. Treat any normal return as a crash
@@ -3098,6 +3111,7 @@ async def _ensure_state_for_transcript(
     transcript_path: Path,
     start_at_end: bool,
     session_id: str,
+    start_at_offset: int | None = None,
 ) -> TranscriptForwardState:
     """
     Return a cursor state compatible with the observed transcript.
@@ -3106,9 +3120,14 @@ async def _ensure_state_for_transcript(
     :param state: Existing cursor state, or ``None``.
     :param transcript_path: Current transcript path from hooks.
     :param start_at_end: Whether a missing cursor should skip the
-        transcript's existing lines.
+        transcript's existing lines. Only consulted when
+        *start_at_offset* is ``None``.
     :param session_id: Omnigent session/conversation id, e.g.
         ``"conv_abc123"``. Used for stale-cursor diagnostics.
+    :param start_at_offset: Exact byte length of a prefix this launch
+        synthesized itself, e.g. ``5920``. Takes precedence over
+        *start_at_end* — see the seeding comment below for why a measured
+        prefix is required rather than a live ``stat``.
     :returns: Cursor state for ``transcript_path``.
     """
     if state is not None and state.transcript_path == transcript_path:
@@ -3131,7 +3150,22 @@ async def _ensure_state_for_transcript(
             await _write_forward_state_async(bridge_dir, validated)
         return validated
     byte_offset = 0
-    if start_at_end:
+    if start_at_offset is not None:
+        # Cold resume: the caller wrote the prefix and measured it before
+        # launching Claude, so skip exactly that and nothing else.
+        #
+        # Seeding from a live ``stat`` here loses messages. Resolving
+        # ``transcript_path`` requires Claude to boot and fire its first hook,
+        # and the executor's ``inject_user_message`` waits on the same boot —
+        # the two are unordered, so the paste routinely wins. Whatever Claude
+        # wrote in that window (the user's prompt included) then sits *behind*
+        # the seeded cursor and is skipped for the session's lifetime: visible
+        # in the TUI pane, absent from the Omnigent DB, with no error anywhere.
+        end_offset = await asyncio.to_thread(_transcript_end_offset, transcript_path)
+        byte_offset = min(start_at_offset, end_offset)
+    elif start_at_end:
+        # Reattach: nothing was synthesized, so the whole existing transcript
+        # is content Omnigent already holds and a live end-offset is correct.
         byte_offset = await asyncio.to_thread(_transcript_end_offset, transcript_path)
     state = TranscriptForwardState(
         transcript_path=transcript_path,
diff --git a/omnigent/runner/native/orchestration.py b/omnigent/runner/native/orchestration.py
index 347487b1dc..0def231167 100644
--- a/omnigent/runner/native/orchestration.py
+++ b/omnigent/runner/native/orchestration.py
@@ -5561,6 +5561,30 @@ def _publish_terminal_pending(
     )
 
 
+def _measured_prefix_bytes(transcript_path: Path) -> int | None:
+    """
+    Measure a just-written resume transcript so the forwarder can skip exactly it.
+
+    Taken before Claude launches, while the file holds only the synthesized
+    prefix. ``None`` on any read failure, which leaves the forwarder on its
+    live end-offset fallback.
+
+    :param transcript_path: Resume transcript this launch wrote, e.g.
+        ``Path("~/.claude/projects/-Users-me-repo/<sid>.jsonl")``.
+    :returns: File size in bytes, or ``None`` when it cannot be measured.
+    """
+    try:
+        return transcript_path.stat().st_size
+    except OSError:
+        _logger.warning(
+            "Could not measure synthesized Claude resume transcript; "
+            "forwarder will seed from the live transcript end; transcript=%s",
+            transcript_path,
+            exc_info=True,
+        )
+        return None
+
+
 def _native_terminal_start_error_payload(exc: BaseException, runtime_name: str) -> dict[str, str]:
     """
     Build the structured error payload for a native terminal start failure.
@@ -6153,6 +6177,12 @@ async def _auto_create_claude_terminal(
     # transcript that doesn't exist. See
     # designs/NATIVE_RUNNER_SERVER_LAUNCH.md.
     resume_external_session_id: str | None = None
+    # Byte length of the resume transcript this launch synthesized, measured
+    # BEFORE Claude starts. The forwarder seeds its cursor from this rather than
+    # from a live end-offset: resolving the transcript path needs Claude's first
+    # hook, and the executor's prompt inject waits on the same boot, so a
+    # ``stat`` taken later routinely skips the freshly-injected message.
+    resume_prefix_bytes: int | None = None
     if server_client is not None and session_external_id is not None:
         from omnigent.claude_native import _ensure_local_claude_resume_transcript
 
@@ -6165,6 +6195,7 @@ async def _auto_create_claude_terminal(
             )
             if _transcript is not None:
                 resume_external_session_id = session_external_id
+                resume_prefix_bytes = _measured_prefix_bytes(_transcript)
         except Exception:  # noqa: BLE001 — best-effort; launch fresh on failure
             _logger.warning(
                 "Could not synthesize Claude resume transcript for %s; launching without --resume",
@@ -6211,6 +6242,7 @@ async def _auto_create_claude_terminal(
         if _cloned is not None:
             # Resume our OWN clone (plain --resume, no --fork-session).
             resume_external_session_id = our_uuid
+            resume_prefix_bytes = _measured_prefix_bytes(_cloned)
             # Record the assigned id now so Omnigent reflects the clone's own
             # Claude session immediately, and a later relaunch resumes it
             # via the normal cold-resume path (this branch is gated on
@@ -6273,6 +6305,7 @@ async def _auto_create_claude_terminal(
         )
         if _built is not None:
             resume_external_session_id = our_uuid
+            resume_prefix_bytes = _measured_prefix_bytes(_built)
             # Record the assigned id so Omnigent reflects the clone's own Claude
             # session and a later relaunch resumes it via the cold-resume
             # path above. Best-effort, mirroring the clone branch.
@@ -6586,6 +6619,7 @@ async def _supervise_bridge() -> None:
                 bridge_dir=bridge_dir,
                 agent_name="claude-native-ui",
                 start_at_end=resume_external_session_id is not None,
+                start_at_offset=resume_prefix_bytes,
                 auth=_runner_auth,
             )
         finally:
diff --git a/tests/test_claude_native_forwarder.py b/tests/test_claude_native_forwarder.py
index 83705378be..cd409e3a07 100644
--- a/tests/test_claude_native_forwarder.py
+++ b/tests/test_claude_native_forwarder.py
@@ -2312,6 +2312,100 @@ async def test_forwarder_waits_for_missing_fresh_transcript_without_warning(
     assert "cursor fingerprint changed" not in caplog.text
 
 
+@pytest.mark.asyncio
+async def test_measured_prefix_seed_keeps_a_prompt_injected_during_boot(
+    tmp_path: Path,
+) -> None:
+    """
+    Regression: a prompt Claude records while booting must still forward.
+
+    Cold resume writes the transcript prefix itself, then launches Claude. The
+    forwarder cannot seed until Claude's first hook advertises the transcript
+    path — and the executor's ``inject_user_message`` waits on the same boot,
+    so the paste routinely lands first. Seeding from a live end-offset then
+    puts the user's prompt BEHIND the cursor: visible in the TUI pane, absent
+    from the Omnigent DB, silently, for the session's lifetime.
+
+    Passing the prefix length measured before launch makes the skip exactly the
+    prefix, so the boot-window records survive however late the seed runs.
+    """
+    bridge_dir = tmp_path / "bridge"
+    bridge_dir.mkdir()
+    transcript_path = tmp_path / "session.jsonl"
+    # The synthesized prefix, complete before Claude starts.
+    transcript_path.write_text(
+        "".join(
+            json.dumps({"type": "user", "uuid": f"old{n}", "message": {"role": "user"}}) + "\n"
+            for n in range(3)
+        ),
+        encoding="utf-8",
+    )
+    prefix_bytes = transcript_path.stat().st_size
+    # Claude boots and records the freshly-injected prompt before the forwarder
+    # is scheduled to seed.
+    with transcript_path.open("a", encoding="utf-8") as handle:
+        handle.write(
+            json.dumps(
+                {
+                    "type": "user",
+                    "uuid": "boot-window-prompt",
+                    "message": {"role": "user", "content": "wake up and check the deploy"},
+                }
+            )
+            + "\n"
+        )
+
+    state = await forwarder._ensure_state_for_transcript(
+        bridge_dir=bridge_dir,
+        state=None,
+        transcript_path=transcript_path,
+        start_at_end=True,
+        session_id="conv_boot_window",
+        start_at_offset=prefix_bytes,
+    )
+
+    # The measured prefix wins over ``start_at_end``: the cursor sits at the
+    # prefix boundary, not at EOF, so the prompt is still ahead of it.
+    assert state.byte_offset == prefix_bytes
+    result = forwarder._read_transcript_items_for_state(state, "claude-native-ui", None)
+    forwarded = [
+        block.get("text")
+        for item in result.items
+        for block in (item.data.get("content") or [])
+        if isinstance(block, dict)
+    ]
+    assert "wake up and check the deploy" in forwarded
+
+
+@pytest.mark.asyncio
+async def test_measured_prefix_never_seeks_past_the_transcript_end(tmp_path: Path) -> None:
+    """
+    A prefix length larger than the file clamps to the end.
+
+    Defensive: the measurement and the seed are separated by Claude's launch,
+    so a truncated or replaced transcript would otherwise leave the cursor
+    beyond EOF, where every later read looks like a stale-cursor reset.
+    """
+    bridge_dir = tmp_path / "bridge"
+    bridge_dir.mkdir()
+    transcript_path = tmp_path / "session.jsonl"
+    transcript_path.write_text(
+        json.dumps({"type": "user", "uuid": "only", "message": {"role": "user"}}) + "\n",
+        encoding="utf-8",
+    )
+
+    state = await forwarder._ensure_state_for_transcript(
+        bridge_dir=bridge_dir,
+        state=None,
+        transcript_path=transcript_path,
+        start_at_end=True,
+        session_id="conv_clamp",
+        start_at_offset=10**9,
+    )
+
+    assert state.byte_offset == transcript_path.stat().st_size
+
+
 @pytest.mark.asyncio
 async def test_forwarder_skips_to_end_on_stale_byte_cursor_state(tmp_path: Path) -> None:
     """