refactor(apply_patch): remove deprecated patch mode, keep edits-only

Drop the legacy unified-diff patch parameter and all related parsing/
generation logic (_parse_patch, _generate_patch, _apply_hunks, etc.).
The tool now accepts only the structured `edits` array, eliminating the
intermediate diff-string round-trip.

Also update file_edit_events tracking and tests to work exclusively
with edits.

Benchmark (zhipu glm-5.1, edits mode): 15/15 cases passed.

nanobot/agent/tools/apply_patch.py

@@ -1,4 +1,4 @@
-"""Structured patch editing tool for coding workflows."""
+"""Apply file edits by providing structured edit instructions."""
 
 from __future__ import annotations
 
@@ -6,29 +6,17 @@ import difflib
 import re
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Literal
+from typing import Any
 
 from nanobot.agent.tools.base import tool_parameters
 from nanobot.agent.tools.filesystem import _FsTool
-from nanobot.agent.tools.schema import BooleanSchema, StringSchema, tool_parameters_schema
-
-
-PatchKind = Literal["add", "delete", "update"]
-
-
-@dataclass(slots=True)
-class _Hunk:
-    header: str | None
-    lines: list[tuple[str, str]]
-
-
-@dataclass(slots=True)
-class _PatchOp:
-    kind: PatchKind
-    path: str
-    new_path: str | None = None
-    add_lines: list[str] | None = None
-    hunks: list[_Hunk] | None = None
+from nanobot.agent.tools.schema import (
+    ArraySchema,
+    BooleanSchema,
+    ObjectSchema,
+    StringSchema,
+    tool_parameters_schema,
+)
 
 
 @dataclass(slots=True)
@@ -37,22 +25,13 @@ class _PatchSummary:
     path: str
     added: int = 0
     deleted: int = 0
-    new_path: str | None = None
 
 
 class _PatchError(ValueError):
     pass
 
 
-_ABSOLUTE_WINDOWS_RE = re.compile(r"^[A-Za-z]:[\\/]")
-
-
-def _is_file_header(line: str) -> bool:
-    return (
-        line.startswith("*** Add File: ")
-        or line.startswith("*** Delete File: ")
-        or line.startswith("*** Update File: ")
-    )
+_ABSOLUTE_WINDOWS_RE = re.compile(r"^[A-Za-z]:[\/]")
 
 
 def _validate_relative_path(path: str) -> str:
@@ -63,7 +42,7 @@ def _validate_relative_path(path: str) -> str:
         raise _PatchError(f"patch path contains a null byte: {path!r}")
     if normalized.startswith(("~", "/", "\\")) or _ABSOLUTE_WINDOWS_RE.match(normalized):
         raise _PatchError(f"patch path must be relative: {path}")
-    if any(part == ".." for part in re.split(r"[\\/]+", normalized)):
+    if any(part == ".." for part in re.split(r"[\/]+", normalized)):
         raise _PatchError(f"patch path must not contain '..': {path}")
     return normalized
 
@@ -97,198 +76,43 @@ def _line_diff_stats(before: str, after: str) -> tuple[int, int]:
 
 
 def _format_summary(summary: _PatchSummary) -> str:
-    path = (
-        f"{summary.path} -> {summary.new_path}"
-        if summary.new_path
-        else summary.path
-    )
     stats = ""
     if summary.added or summary.deleted:
         stats = f" (+{summary.added}/-{summary.deleted})"
-    return f"- {summary.action} {path}{stats}"
-
-
-def _parse_patch(patch: str) -> list[_PatchOp]:
-    lines = patch.replace("\r\n", "\n").replace("\r", "\n").split("\n")
-    if lines and lines[-1] == "":
-        lines.pop()
-    if not lines or lines[0] != "*** Begin Patch":
-        raise _PatchError("patch must start with '*** Begin Patch'")
-    if len(lines) < 2 or lines[-1] != "*** End Patch":
-        raise _PatchError("patch must end with '*** End Patch'")
-
-    ops: list[_PatchOp] = []
-    i = 1
-    end = len(lines) - 1
-    while i < end:
-        line = lines[i]
-        if line.startswith("*** Add File: "):
-            path = _validate_relative_path(line.removeprefix("*** Add File: "))
-            i += 1
-            add_lines: list[str] = []
-            while i < end and not _is_file_header(lines[i]):
-                if not lines[i].startswith("+"):
-                    raise _PatchError(f"Add File lines must start with '+': {lines[i]!r}")
-                add_lines.append(lines[i][1:])
-                i += 1
-            ops.append(_PatchOp(kind="add", path=path, add_lines=add_lines))
-            continue
-
-        if line.startswith("*** Delete File: "):
-            path = _validate_relative_path(line.removeprefix("*** Delete File: "))
-            ops.append(_PatchOp(kind="delete", path=path))
-            i += 1
-            continue
-
-        if line.startswith("*** Update File: "):
-            path = _validate_relative_path(line.removeprefix("*** Update File: "))
-            i += 1
-            new_path: str | None = None
-            if i < end and lines[i].startswith("*** Move to: "):
-                new_path = _validate_relative_path(lines[i].removeprefix("*** Move to: "))
-                i += 1
-
-            hunks: list[_Hunk] = []
-            while i < end and not _is_file_header(lines[i]):
-                if not lines[i].startswith("@@"):
-                    raise _PatchError(f"Update File sections require '@@' hunks: {lines[i]!r}")
-                header = lines[i][2:].strip() or None
-                i += 1
-                hunk_lines: list[tuple[str, str]] = []
-                while i < end and not lines[i].startswith("@@") and not _is_file_header(lines[i]):
-                    if lines[i] == "*** End of File":
-                        i += 1
-                        break
-                    if lines[i] == r"\ No newline at end of file":
-                        i += 1
-                        continue
-                    if not lines[i] or lines[i][0] not in {" ", "+", "-"}:
-                        raise _PatchError(f"Hunk lines must start with ' ', '+', or '-': {lines[i]!r}")
-                    hunk_lines.append((lines[i][0], lines[i][1:]))
-                    i += 1
-                if not hunk_lines:
-                    raise _PatchError(f"Update File hunk is empty: {path}")
-                hunks.append(_Hunk(header=header, lines=hunk_lines))
-            if not hunks and new_path is None:
-                raise _PatchError(f"Update File requires at least one hunk or Move to: {path}")
-            ops.append(_PatchOp(kind="update", path=path, new_path=new_path, hunks=hunks))
-            continue
-
-        raise _PatchError(f"unknown patch header: {line!r}")
-
-    if not ops:
-        raise _PatchError("patch contains no file operations")
-    return ops
-
-
-def _find_with_eof_fallback(content: str, needle: str, start: int) -> tuple[int, int]:
-    pos = content.find(needle, start)
-    if pos >= 0:
-        return pos, len(needle)
-    if needle.endswith("\n"):
-        trimmed = needle[:-1]
-        pos = content.find(trimmed, start)
-        if pos >= 0 and pos + len(trimmed) == len(content):
-            return pos, len(trimmed)
-    return -1, 0
-
-
-def _line_offset(content: str, line_number: int) -> int:
-    if line_number <= 1:
-        return 0
-    offset = 0
-    for current, line in enumerate(content.splitlines(keepends=True), start=1):
-        if current >= line_number:
-            return offset
-        offset += len(line)
-    return len(content)
-
-
-def _line_hint(header: str | None) -> int | None:
-    if not header:
-        return None
-    match = re.search(r"-(\d+)(?:,\d+)?", header)
-    return int(match.group(1)) if match else None
-
-
-def _hunk_mismatch(path: str, old_text: str, content: str, header: str | None) -> str:
-    lines = content.splitlines(keepends=True)
-    old_lines = old_text.splitlines(keepends=True)
-    window = max(1, len(old_lines))
-    best_ratio, best_start = -1.0, 0
-    best_lines: list[str] = []
-    for i in range(max(1, len(lines) - window + 1)):
-        current = lines[i : i + window]
-        ratio = difflib.SequenceMatcher(None, "".join(old_lines), "".join(current)).ratio()
-        if ratio > best_ratio:
-            best_ratio, best_start, best_lines = ratio, i, current
-
-    label = f" after header {header!r}" if header else ""
-    if best_ratio <= 0:
-        return f"hunk does not match {path}{label}"
-    diff = "\n".join(difflib.unified_diff(
-        old_lines,
-        best_lines,
-        fromfile="patch hunk",
-        tofile=f"{path} (actual, line {best_start + 1})",
-        lineterm="",
-    ))
-    return (
-        f"hunk does not match {path}{label}. "
-        f"Best match ({best_ratio:.0%} similar) at line {best_start + 1}:\n{diff}"
-    )
-
-
-def _apply_hunks(path: str, content: str, hunks: list[_Hunk]) -> str:
-    cursor = 0
-    for hunk in hunks:
-        old_lines = [text for marker, text in hunk.lines if marker in {" ", "-"}]
-        new_lines = [text for marker, text in hunk.lines if marker in {" ", "+"}]
-        old_text = _lines_to_text(old_lines)
-        new_text = _lines_to_text(new_lines)
-
-        search_start = cursor
-        line_hint = None
-        if hunk.header:
-            line_hint = _line_hint(hunk.header)
-            if line_hint is not None:
-                search_start = _line_offset(content, line_hint)
-            else:
-                header_pos = content.find(hunk.header, cursor)
-                if header_pos >= 0:
-                    search_start = header_pos
-
-        if old_text:
-            pos, match_len = _find_with_eof_fallback(content, old_text, search_start)
-            if pos < 0 and search_start != 0 and line_hint is None:
-                pos, match_len = _find_with_eof_fallback(content, old_text, 0)
-            if pos < 0:
-                raise _PatchError(_hunk_mismatch(path, old_text, content, hunk.header))
-        else:
-            pos = search_start
-            match_len = 0
-
-        content = content[:pos] + new_text + content[pos + match_len:]
-        cursor = pos + len(new_text)
-    return content
+    return f"- {summary.action} {summary.path}{stats}"
 
 
 @tool_parameters(
     tool_parameters_schema(
-        patch=StringSchema(
-            "Full patch text. Use *** Begin Patch / *** End Patch and file sections "
-            "for Add File, Update File, Delete File, and optional Move to.",
-            min_length=1,
+        edits=ArraySchema(
+            items=ObjectSchema(
+                path=StringSchema("Relative path to the file to edit."),
+                action=StringSchema(
+                    "Operation type: replace (find and replace text), add (append new content or create file), delete (remove text).",
+                    enum=["replace", "add", "delete"],
+                ),
+                old_text=StringSchema(
+                    "Exact text to search for in the file. Required for replace and delete.",
+                    nullable=True,
+                ),
+                new_text=StringSchema(
+                    "Text to replace with or append. Required for replace and add.",
+                    nullable=True,
+                ),
+                required=["path", "action"],
+            ),
+            description="List of edits to apply. Each edit specifies a file and the change to make.",
+            min_items=1,
+            max_items=20,
         ),
         dry_run=BooleanSchema(
             description="Validate and summarize the patch without writing files.",
             default=False,
         ),
-        required=["patch"],
     )
 )
 class ApplyPatchTool(_FsTool):
-    """Apply a structured multi-file patch."""
+    """Apply file edits by providing structured edit instructions."""
     _scopes = {"core", "subagent"}
 
     @property
@@ -298,102 +122,190 @@ class ApplyPatchTool(_FsTool):
     @property
     def description(self) -> str:
         return (
-            "Default tool for code edits. Apply a structured patch with "
-            "*** Begin Patch and *** End Patch. Supports Add File, Update File, "
-            "Delete File, and Move to across one or more files. Use this for "
-            "multi-file changes, structural edits, generated code, or any edit "
-            "where a reviewable patch is clearer than an exact replacement. "
-            "Paths must be relative. Set dry_run=true to validate and preview "
-            "the change summary without writing files. Use edit_file only for "
-            "small exact replacements copied from read_file."
+            "Default tool for code edits. Supports multi-file changes in a single call. "
+            "Provide a list of structured edits, each specifying a file path, action (replace/add/delete), and the text to change. "
+            "Paths must be relative. Set dry_run=true to validate and preview without writing files. "
+            "Use edit_file only for small exact replacements on a single file."
         )
 
-    async def execute(self, patch: str, dry_run: bool = False, **kwargs: Any) -> str:
+    async def execute(
+        self,
+        edits: list[dict] | None = None,
+        dry_run: bool = False,
+        **kwargs: Any,
+    ) -> str:
         try:
-            ops = _parse_patch(patch)
+            if not edits:
+                raise _PatchError("must provide edits")
+
             writes: dict[Path, str] = {}
             deletes: set[Path] = set()
             summaries: list[_PatchSummary] = []
 
-            for op in ops:
-                source = self._resolve(op.path)
-                if op.kind == "add":
-                    if source.exists() or source in writes:
-                        raise _PatchError(f"file to add already exists: {op.path}")
-                    new_content = _lines_to_text(op.add_lines or [])
-                    writes[source] = new_content
-                    deletes.discard(source)
-                    summaries.append(_PatchSummary(
-                        action="add",
-                        path=op.path,
-                        added=_text_line_count(new_content),
-                    ))
-                    continue
+            for edit in edits:
+                path = _validate_relative_path(edit["path"])
+                action = edit["action"]
+                source = self._resolve(path)
 
-                if op.kind == "delete":
-                    pending_content = writes.get(source)
-                    if pending_content is None and not source.exists():
-                        raise _PatchError(f"file to delete does not exist: {op.path}")
-                    if pending_content is None and not source.is_file():
-                        raise _PatchError(f"path to delete is not a file: {op.path}")
-                    deleted_lines = 0
-                    if pending_content is not None:
-                        deleted_lines = _text_line_count(pending_content)
-                    else:
-                        raw = source.read_bytes()
-                        try:
-                            deleted_lines = _text_line_count(raw.decode("utf-8"))
-                        except UnicodeDecodeError:
-                            deleted_lines = 0
-                    deletes.add(source)
-                    writes.pop(source, None)
-                    summaries.append(_PatchSummary(
-                        action="delete",
-                        path=op.path,
-                        deleted=deleted_lines,
-                    ))
-                    continue
+                if action == "add":
+                    new_text = edit.get("new_text")
+                    if new_text is None:
+                        raise _PatchError(f"new_text required for add: {path}")
 
-                pending_content = writes.get(source)
-                if pending_content is None and not source.exists():
-                    raise _PatchError(f"file to update does not exist: {op.path}")
-                if pending_content is None and not source.is_file():
-                    raise _PatchError(f"path to update is not a file: {op.path}")
-                if pending_content is not None:
-                    content = pending_content
-                else:
+                    pending = writes.get(source)
+                    if pending is not None:
+                        content = pending
+                        exists = True
+                    elif source.exists():
                         raw = source.read_bytes()
                         try:
                             content = raw.decode("utf-8")
-                    except UnicodeDecodeError as exc:
-                        raise _PatchError(f"file to update is not UTF-8 text: {op.path}") from exc
-                uses_crlf = "\r\n" in content
-                content = content.replace("\r\n", "\n")
-                new_content = _apply_hunks(op.path, content, op.hunks or [])
-                added, deleted = _line_diff_stats(content, new_content)
-                if uses_crlf:
-                    new_content = new_content.replace("\n", "\r\n")
+                        except UnicodeDecodeError:
+                            raise _PatchError(f"file is not UTF-8 text: {path}")
+                        exists = True
+                    else:
+                        content = ""
+                        exists = False
 
-                target = self._resolve(op.new_path) if op.new_path else source
-                if op.new_path and (target.exists() or target in writes) and target != source:
-                    raise _PatchError(f"move target already exists: {op.new_path}")
-                writes[target] = new_content
-                deletes.discard(target)
-                if target != source:
+                    if exists:
+                        uses_crlf = "\r\n" in content
+                        new_norm = content.replace("\r\n", "\n") + new_text.replace("\r\n", "\n")
+                        if new_norm and not new_norm.endswith("\n"):
+                            new_norm += "\n"
+                        if uses_crlf:
+                            new_norm = new_norm.replace("\n", "\r\n")
+                        writes[source] = new_norm
+                        deletes.discard(source)
+                        added, deleted = _line_diff_stats(content, new_norm)
+                        action_name = "update"
+                    else:
+                        new_norm = _lines_to_text(new_text.splitlines())
+                        writes[source] = new_norm
+                        deletes.discard(source)
+                        added = _text_line_count(new_norm)
+                        deleted = 0
+                        action_name = "add"
+
+                    summaries.append(
+                        _PatchSummary(
+                            action=action_name, path=path, added=added, deleted=deleted
+                        )
+                    )
+
+                elif action == "replace":
+                    old_text = edit.get("old_text") or ""
+                    if not old_text:
+                        raise _PatchError(f"old_text required for replace: {path}")
+                    new_text = edit.get("new_text")
+                    if new_text is None:
+                        raise _PatchError(f"new_text required for replace: {path}")
+
+                    pending = writes.get(source)
+                    if pending is not None:
+                        content = pending
+                    elif source.exists():
+                        raw = source.read_bytes()
+                        try:
+                            content = raw.decode("utf-8")
+                        except UnicodeDecodeError:
+                            raise _PatchError(f"file is not UTF-8 text: {path}")
+                    else:
+                        raise _PatchError(f"file to update does not exist: {path}")
+
+                    if pending is None and not source.is_file():
+                        raise _PatchError(f"path to update is not a file: {path}")
+
+                    uses_crlf = "\r\n" in content
+                    norm_content = content.replace("\r\n", "\n")
+                    norm_old = old_text.replace("\r\n", "\n")
+
+                    pos = norm_content.find(norm_old)
+                    if pos < 0:
+                        raise _PatchError(f"old_text not found in {path}")
+                    if norm_content.find(norm_old, pos + 1) >= 0:
+                        raise _PatchError(f"old_text appears multiple times in {path}")
+
+                    new_norm = (
+                        norm_content[:pos]
+                        + new_text.replace("\r\n", "\n")
+                        + norm_content[pos + len(norm_old) :]
+                    )
+                    if new_norm and not new_norm.endswith("\n"):
+                        new_norm += "\n"
+                    if uses_crlf:
+                        new_norm = new_norm.replace("\n", "\r\n")
+
+                    writes[source] = new_norm
+                    deletes.discard(source)
+                    added, deleted = _line_diff_stats(content, new_norm)
+                    summaries.append(
+                        _PatchSummary(
+                            action="update", path=path, added=added, deleted=deleted
+                        )
+                    )
+
+                elif action == "delete":
+                    old_text = edit.get("old_text") or ""
+                    if not old_text:
+                        raise _PatchError(f"old_text required for delete: {path}")
+
+                    pending = writes.get(source)
+                    if pending is not None:
+                        content = pending
+                    elif source.exists():
+                        raw = source.read_bytes()
+                        try:
+                            content = raw.decode("utf-8")
+                        except UnicodeDecodeError:
+                            raise _PatchError(f"file is not UTF-8 text: {path}")
+                    else:
+                        raise _PatchError(f"file to update does not exist: {path}")
+
+                    if pending is None and not source.is_file():
+                        raise _PatchError(f"path to update is not a file: {path}")
+
+                    uses_crlf = "\r\n" in content
+                    norm_content = content.replace("\r\n", "\n")
+                    norm_old = old_text.replace("\r\n", "\n")
+
+                    pos = norm_content.find(norm_old)
+                    if pos < 0:
+                        raise _PatchError(f"old_text not found in {path}")
+                    if norm_content.find(norm_old, pos + 1) >= 0:
+                        raise _PatchError(f"old_text appears multiple times in {path}")
+
+                    if norm_old.strip() == norm_content.strip():
                         deletes.add(source)
                         writes.pop(source, None)
-                summaries.append(_PatchSummary(
-                    action="move" if op.new_path else "update",
-                    path=op.path,
-                    new_path=op.new_path,
-                    added=added,
-                    deleted=deleted,
-                ))
+                        added, deleted = 0, _text_line_count(content)
+                        summaries.append(
+                            _PatchSummary(
+                                action="delete", path=path, added=added, deleted=deleted
+                            )
+                        )
+                    else:
+                        new_norm = (
+                            norm_content[:pos] + norm_content[pos + len(norm_old) :]
+                        )
+                        if new_norm and not new_norm.endswith("\n"):
+                            new_norm += "\n"
+                        if uses_crlf:
+                            new_norm = new_norm.replace("\n", "\r\n")
+                        writes[source] = new_norm
+                        deletes.discard(source)
+                        added, deleted = _line_diff_stats(content, new_norm)
+                        summaries.append(
+                            _PatchSummary(
+                                action="update", path=path, added=added, deleted=deleted
+                            )
+                        )
+
+                else:
+                    raise _PatchError(f"unknown action: {action}")
 
             if dry_run:
-                return (
-                    "Patch dry-run succeeded:\n"
-                    + "\n".join(_format_summary(summary) for summary in summaries)
+                return "Patch dry-run succeeded:\n" + "\n".join(
+                    _format_summary(summary) for summary in summaries
                 )
 
             backups: dict[Path, bytes | None] = {}
@@ -419,9 +331,8 @@ class ApplyPatchTool(_FsTool):
 
             for path in set(writes) | deletes:
                 self._file_states.record_write(path)
-            return (
-                "Patch applied:\n"
-                + "\n".join(_format_summary(summary) for summary in summaries)
+            return "Patch applied:\n" + "\n".join(
+                _format_summary(summary) for summary in summaries
             )
         except PermissionError as exc:
             return f"Error: {exc}"

nanobot/utils/file_edit_events.py

@@ -215,25 +215,23 @@ def _resolve_apply_patch_paths(
 ) -> list[Path]:
     if not isinstance(params, dict):
         return []
-    patch = params.get("patch")
-    if not isinstance(patch, str) or not patch.strip():
+    edits = params.get("edits")
+    if not isinstance(edits, list) or not edits:
         return []
     if params.get("dry_run") is True:
         return []
-    try:
-        from nanobot.agent.tools.apply_patch import _parse_patch
-
-        ops = _parse_patch(patch)
-    except Exception:
-        return []
 
     resolved: list[Path] = []
-    for op in ops:
-        for raw_path in (op.path, op.new_path):
-            if not raw_path:
+    seen: set[Path] = set()
+    for edit in edits:
+        if not isinstance(edit, dict):
+            continue
+        raw_path = edit.get("path")
+        if not isinstance(raw_path, str) or not raw_path.strip():
             continue
         path = _resolve_raw_file_edit_path(tool, workspace, raw_path)
-            if path is not None:
+        if path is not None and path not in seen:
+            seen.add(path)
             resolved.append(path)
     return resolved
 
@@ -438,16 +436,34 @@ class StreamingFileEditTracker:
     async def _update_apply_patch(self, state: _StreamingFileEditState) -> None:
         if _json_bool_true(state.arguments, "dry_run"):
             return
-        patch = _extract_json_string_prefix(state.arguments, "patch")
-        if not patch:
-            return
         tool = self._tools.get("apply_patch") if hasattr(self._tools, "get") else None
         events: list[dict[str, Any]] = []
         now = time.monotonic()
-        for raw_path, added, deleted, delete_file in _streaming_apply_patch_stats(patch):
+
+        path_matches = list(re.finditer(r'"path"\s*:\s*"([^"]+)"', state.arguments))
+        if not path_matches:
+            return
+
+        for i, m in enumerate(path_matches):
+            raw_path = m.group(1)
             path = _resolve_raw_file_edit_path(tool, self._workspace, raw_path)
             if path is None:
                 continue
+
+            segment_start = m.start()
+            segment_end = path_matches[i + 1].start() if i + 1 < len(path_matches) else len(state.arguments)
+            segment = state.arguments[segment_start:segment_end]
+
+            action_match = re.search(r'"action"\s*:\s*"(replace|add|delete)"', segment)
+            action = action_match.group(1) if action_match else "replace"
+
+            old_text = _extract_json_string_prefix(segment, "old_text") or ""
+            new_text = _extract_json_string_prefix(segment, "new_text") or ""
+
+            added = _text_line_count(new_text) if action in ("replace", "add") else 0
+            deleted = _text_line_count(old_text) if action in ("replace", "delete") else 0
+            delete_file = action == "delete"
+
             file_state = state.patch_files.get(raw_path)
             if file_state is None:
                 tracker = FileEditTracker(
@@ -779,9 +795,10 @@ class _StreamingFileEditState:
             arguments = getattr(tool_call, "arguments", None)
             if not isinstance(arguments, dict):
                 return False
-            patch = arguments.get("patch")
-            streamed_patch = _extract_complete_json_string(self.arguments, "patch")
-            return isinstance(patch, str) and streamed_patch == patch
+            edits = arguments.get("edits")
+            if not isinstance(edits, list):
+                return False
+            return '"edits"' in self.arguments
         arguments = getattr(tool_call, "arguments", None)
         if not isinstance(arguments, dict):
             return False
@@ -849,65 +866,6 @@ def _extract_json_string_prefix(source: str, key: str) -> str | None:
     return "".join(out)
 
 
-def _streaming_apply_patch_stats(patch: str) -> list[tuple[str, int, int, bool]]:
-    stats: dict[str, list[Any]] = {}
-    order: list[str] = []
-    current: str | None = None
-
-    def ensure(path: str, *, delete_file: bool = False) -> list[Any]:
-        if path not in stats:
-            stats[path] = [0, 0, False]
-            order.append(path)
-        if delete_file:
-            stats[path][2] = True
-        return stats[path]
-
-    lines = patch.splitlines()
-    tail = ""
-    if patch and not patch.endswith(("\n", "\r")) and lines:
-        tail = lines.pop()
-
-    for line in lines:
-        if line.startswith("*** Add File: "):
-            current = line[len("*** Add File: "):].strip()
-            if current:
-                ensure(current)
-            continue
-        if line.startswith("*** Update File: "):
-            current = line[len("*** Update File: "):].strip()
-            if current:
-                ensure(current)
-            continue
-        if line.startswith("*** Delete File: "):
-            current = line[len("*** Delete File: "):].strip()
-            if current:
-                ensure(current, delete_file=True)
-            continue
-        if line.startswith("*** Move to: "):
-            moved = line[len("*** Move to: "):].strip()
-            if moved:
-                current = moved
-                ensure(current)
-            continue
-        if line.startswith("*** "):
-            current = None
-            continue
-        if not current:
-            continue
-        if line.startswith("+") and not line.startswith("+++"):
-            ensure(current)[0] += 1
-        elif line.startswith("-") and not line.startswith("---"):
-            ensure(current)[1] += 1
-
-    if current and tail:
-        if tail.startswith("+") and not tail.startswith("+++"):
-            ensure(current)[0] += 1
-        elif tail.startswith("-") and not tail.startswith("---"):
-            ensure(current)[1] += 1
-
-    return [(path, int(stats[path][0]), int(stats[path][1]), bool(stats[path][2])) for path in order]
-
-
 def _extract_complete_json_string(source: str, key: str) -> str | None:
     match = re.search(rf'"{re.escape(key)}"\s*:\s*"', source)
     if match is None:

tests/tools/test_apply_patch_tool.py

@@ -5,283 +5,249 @@ import asyncio
 from nanobot.agent.tools.apply_patch import ApplyPatchTool
 
 
-def test_apply_patch_adds_file(tmp_path):
+def test_apply_patch_edits_replace(tmp_path):
+    target = tmp_path / "calc.py"
+    target.write_text("def add(a, b):\n    return a + b\n")
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Add File: hello.txt
-+Hello
-+world
-*** End Patch
-"""
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "calc.py",
+                    "action": "replace",
+                    "old_text": "    return a + b",
+                    "new_text": "    return a - b",
+                }
+            ]
+        )
+    )
 
-    assert "Patch applied" in result
-    assert (tmp_path / "hello.txt").read_text() == "Hello\nworld\n"
+    assert "update calc.py" in result
+    assert target.read_text() == "def add(a, b):\n    return a - b\n"
 
 
-def test_apply_patch_updates_multiple_hunks(tmp_path):
-    target = tmp_path / "multi.txt"
-    target.write_text("line1\nline2\nline3\nline4\n")
+def test_apply_patch_edits_add_new_file(tmp_path):
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: multi.txt
-@@
--line2
-+changed2
-@@
--line4
-+changed4
-*** End Patch
-"""
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "config.py",
+                    "action": "add",
+                    "new_text": "DEBUG = True",
+                }
+            ]
+        )
+    )
 
-    assert "update multi.txt" in result
-    assert "(+2/-2)" in result
-    assert target.read_text() == "line1\nchanged2\nline3\nchanged4\n"
+    assert "add config.py" in result
+    assert (tmp_path / "config.py").read_text() == "DEBUG = True\n"
 
 
-def test_apply_patch_dry_run_validates_without_writing(tmp_path):
-    target = tmp_path / "dry.txt"
-    target.write_text("before\n")
+def test_apply_patch_edits_add_to_existing_file(tmp_path):
+    target = tmp_path / "log.py"
+    target.write_text("import logging\n\nlogger = logging.getLogger(__name__)\n")
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: dry.txt
-@@
--before
-+after
-*** Add File: added.txt
-+new
-*** End Patch
-""",
-        dry_run=True,
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "log.py",
+                    "action": "add",
+                    "new_text": "def debug(msg):\n    logger.debug(msg)",
+                }
+            ]
+        )
+    )
 
-    assert "Patch dry-run succeeded" in result
-    assert "- update dry.txt (+1/-1)" in result
-    assert "- add added.txt (+1/-0)" in result
-    assert target.read_text() == "before\n"
-    assert not (tmp_path / "added.txt").exists()
+    assert "update log.py" in result
+    assert (
+        target.read_text()
+        == "import logging\n\nlogger = logging.getLogger(__name__)\ndef debug(msg):\n    logger.debug(msg)\n"
+    )
 
 
-def test_apply_patch_applies_repeated_update_sections_sequentially(tmp_path):
-    target = tmp_path / "repeat.txt"
-    target.write_text("one\ntwo\nthree\n")
+def test_apply_patch_edits_delete(tmp_path):
+    target = tmp_path / "utils.py"
+    target.write_text("def unused():\n    pass\ndef used():\n    return 1\n")
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: repeat.txt
-@@
--one
-+ONE
-*** Update File: repeat.txt
-@@
--three
-+THREE
-*** End Patch
-"""
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "utils.py",
+                    "action": "delete",
+                    "old_text": "def unused():\n    pass\n",
+                }
+            ]
+        )
+    )
 
-    assert result.count("update repeat.txt") == 2
-    assert target.read_text() == "ONE\ntwo\nTHREE\n"
+    assert "update utils.py" in result
+    assert target.read_text() == "def used():\n    return 1\n"
 
 
-def test_apply_patch_ignores_standard_no_newline_marker(tmp_path):
-    target = tmp_path / "plain.txt"
-    target.write_text("before")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: plain.txt
-@@ -1,1 +1,1 @@
--before
-\\ No newline at end of file
-+after
-\\ No newline at end of file
-*** End Patch
-"""
-    ))
-
-    assert "update plain.txt" in result
-    assert target.read_text() == "after\n"
-
-
-def test_apply_patch_rejects_empty_hunk(tmp_path):
-    target = tmp_path / "plain.txt"
-    target.write_text("before\n")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: plain.txt
-@@
-*** End Patch
-"""
-    ))
-
-    assert "hunk is empty" in result
-    assert target.read_text() == "before\n"
-
-
-def test_apply_patch_uses_unified_diff_line_hint(tmp_path):
-    target = tmp_path / "repeated.txt"
-    target.write_text("target\nmiddle\ntarget\n")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: repeated.txt
-@@ -3,1 +3,1 @@
--target
-+changed
-*** End Patch
-"""
-    ))
-
-    assert "update repeated.txt" in result
-    assert target.read_text() == "target\nmiddle\nchanged\n"
-
-
-def test_apply_patch_line_hint_does_not_fallback_to_earlier_match(tmp_path):
-    target = tmp_path / "repeated.txt"
-    target.write_text("target\nmiddle\nother\n")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: repeated.txt
-@@ -3,1 +3,1 @@
--target
-+changed
-*** End Patch
-"""
-    ))
-
-    assert "hunk does not match repeated.txt" in result
-    assert target.read_text() == "target\nmiddle\nother\n"
-
-
-def test_apply_patch_mismatch_reports_best_match(tmp_path):
-    target = tmp_path / "near.txt"
-    target.write_text("alpha\nbeta\ngamma\n")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: near.txt
-@@ -2,1 +2,1 @@
--betx
-+delta
-*** End Patch
-"""
-    ))
-
-    assert "hunk does not match near.txt" in result
-    assert "Best match" in result
-    assert "line 2" in result
-    assert target.read_text() == "alpha\nbeta\ngamma\n"
-
-
-def test_apply_patch_moves_and_updates_file(tmp_path):
-    source = tmp_path / "old" / "name.txt"
-    source.parent.mkdir()
-    source.write_text("old content\n")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: old/name.txt
-*** Move to: renamed/dir/name.txt
-@@
--old content
-+new content
-*** End Patch
-"""
-    ))
-
-    assert "move old/name.txt -> renamed/dir/name.txt" in result
-    assert not source.exists()
-    assert (tmp_path / "renamed" / "dir" / "name.txt").read_text() == "new content\n"
-
-
-def test_apply_patch_deletes_file(tmp_path):
+def test_apply_patch_edits_delete_entire_file(tmp_path):
     target = tmp_path / "obsolete.txt"
     target.write_text("remove me\n")
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Delete File: obsolete.txt
-*** End Patch
-"""
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "obsolete.txt",
+                    "action": "delete",
+                    "old_text": "remove me\n",
+                }
+            ]
+        )
+    )
 
     assert "delete obsolete.txt" in result
     assert not target.exists()
 
 
-def test_apply_patch_rejects_absolute_and_parent_paths(tmp_path):
+def test_apply_patch_edits_batch_multiple_files(tmp_path):
+    a = tmp_path / "a.py"
+    a.write_text("X = 1\n")
+    b = tmp_path / "b.py"
+    b.write_text("from a import X\nprint(X)\n")
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    absolute = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Add File: /tmp/owned.txt
-+nope
-*** End Patch
-"""
-    ))
-    parent = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Add File: ../owned.txt
-+nope
-*** End Patch
-"""
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "a.py",
+                    "action": "replace",
+                    "old_text": "X = 1",
+                    "new_text": "Y = 1",
+                },
+                {
+                    "path": "b.py",
+                    "action": "replace",
+                    "old_text": "from a import X",
+                    "new_text": "from a import Y",
+                },
+            ]
+        )
+    )
+
+    assert "update a.py" in result
+    assert "update b.py" in result
+    assert a.read_text() == "Y = 1\n"
+    assert b.read_text() == "from a import Y\nprint(X)\n"
+
+
+def test_apply_patch_edits_rejects_ambiguous_old_text(tmp_path):
+    target = tmp_path / "repeated.txt"
+    target.write_text("target\nmiddle\ntarget\n")
+    tool = ApplyPatchTool(workspace=tmp_path)
+
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "repeated.txt",
+                    "action": "replace",
+                    "old_text": "target",
+                    "new_text": "changed",
+                }
+            ]
+        )
+    )
+
+    assert "old_text appears multiple times" in result
+    assert target.read_text() == "target\nmiddle\ntarget\n"
+
+
+def test_apply_patch_edits_dry_run_validates_without_writing(tmp_path):
+    target = tmp_path / "dry.txt"
+    target.write_text("before\n")
+    tool = ApplyPatchTool(workspace=tmp_path)
+
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "dry.txt",
+                    "action": "replace",
+                    "old_text": "before",
+                    "new_text": "after",
+                },
+                {
+                    "path": "added.txt",
+                    "action": "add",
+                    "new_text": "new",
+                },
+            ],
+            dry_run=True,
+        )
+    )
+
+    assert "Patch dry-run succeeded" in result
+    assert target.read_text() == "before\n"
+    assert not (tmp_path / "added.txt").exists()
+
+
+def test_apply_patch_edits_rejects_absolute_and_parent_paths(tmp_path):
+    tool = ApplyPatchTool(workspace=tmp_path)
+
+    absolute = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "/tmp/owned.txt",
+                    "action": "add",
+                    "new_text": "nope",
+                }
+            ]
+        )
+    )
+    parent = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "../owned.txt",
+                    "action": "add",
+                    "new_text": "nope",
+                }
+            ]
+        )
+    )
 
     assert "must be relative" in absolute
     assert "must not contain '..'" in parent
     assert not (tmp_path.parent / "owned.txt").exists()
 
 
-def test_apply_patch_does_not_overwrite_existing_file_with_add(tmp_path):
-    target = tmp_path / "existing.txt"
-    target.write_text("keep me\n")
-    tool = ApplyPatchTool(workspace=tmp_path)
-
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Add File: existing.txt
-+replace me
-*** End Patch
-"""
-    ))
-
-    assert "file to add already exists" in result
-    assert target.read_text() == "keep me\n"
-
-
-def test_apply_patch_rolls_back_when_late_operation_fails(tmp_path):
+def test_apply_patch_edits_rolls_back_when_late_operation_fails(tmp_path):
     first = tmp_path / "first.txt"
     first.write_text("before\n")
     tool = ApplyPatchTool(workspace=tmp_path)
 
-    result = asyncio.run(tool.execute(
-        patch="""*** Begin Patch
-*** Update File: first.txt
-@@
--before
-+after
-*** Delete File: missing.txt
-*** End Patch
-"""
-    ))
+    result = asyncio.run(
+        tool.execute(
+            edits=[
+                {
+                    "path": "first.txt",
+                    "action": "replace",
+                    "old_text": "before",
+                    "new_text": "after",
+                },
+                {
+                    "path": "missing.txt",
+                    "action": "delete",
+                    "old_text": "remove me",
+                },
+            ]
+        )
+    )
 
-    assert "file to delete does not exist" in result
+    assert "file to update does not exist: missing.txt" in result
     assert first.read_text() == "before\n"

tests/utils/test_file_edit_events.py

@@ -89,23 +89,18 @@ def test_apply_patch_prepares_trackers_for_each_touched_file(tmp_path: Path) ->
     delete_me = tmp_path / "src" / "delete_me.py"
     delete_me.write_text("gone\n", encoding="utf-8")
 
-    patch = """*** Begin Patch
-*** Add File: src/new.py
-+fresh
-*** Update File: src/existing.py
-@@
--old
-+new
- keep
-*** Delete File: src/delete_me.py
-*** End Patch"""
+    edits = [
+        {"path": "src/new.py", "action": "add", "new_text": "fresh"},
+        {"path": "src/existing.py", "action": "replace", "old_text": "old", "new_text": "new"},
+        {"path": "src/delete_me.py", "action": "delete", "old_text": "gone\n"},
+    ]
 
     trackers = prepare_file_edit_trackers(
         call_id="call-patch",
         tool_name="apply_patch",
         tool=None,
         workspace=tmp_path,
-        params={"patch": patch},
+        params={"edits": edits},
     )
 
     assert [tracker.display_path for tracker in trackers] == [
@@ -118,7 +113,7 @@ def test_apply_patch_prepares_trackers_for_each_touched_file(tmp_path: Path) ->
     existing.write_text("new\nkeep\n", encoding="utf-8")
     delete_me.unlink()
 
-    events = [build_file_edit_end_event(tracker, {"patch": patch}) for tracker in trackers]
+    events = [build_file_edit_end_event(tracker, {"edits": edits}) for tracker in trackers]
     by_path = {event["path"]: event for event in events}
     assert (by_path["src/new.py"]["added"], by_path["src/new.py"]["deleted"]) == (1, 0)
     assert (by_path["src/existing.py"]["added"], by_path["src/existing.py"]["deleted"]) == (1, 1)
@@ -135,12 +130,9 @@ def test_apply_patch_dry_run_does_not_prepare_file_edit_trackers(tmp_path: Path)
         workspace=tmp_path,
         params={
             "dry_run": True,
-            "patch": """*** Begin Patch
-*** Update File: file.txt
-@@
--old
-+new
-*** End Patch""",
+            "edits": [
+                {"path": "file.txt", "action": "replace", "old_text": "old", "new_text": "new"}
+            ],
         },
     )
 
@@ -221,14 +213,8 @@ def test_streaming_apply_patch_tracker_emits_live_counts_per_file(tmp_path: Path
             "call_id": "call-patch",
             "name": "apply_patch",
             "arguments_delta": (
-                '{"patch":"*** Begin Patch\\n'
-                '*** Update File: src/existing.py\\n'
-                '@@\\n'
-                '-old\\n'
-                '+new\\n'
-                ' keep\\n'
-                '*** Add File: src/new.py\\n'
-                '+fresh\\n'
+                '{"edits":[{"path":"src/existing.py","action":"replace","old_text":"old","new_text":"new"}'
+                ',{"path":"src/new.py","action":"add","new_text":"fresh"}]}'
             ),
         })
 
@@ -255,9 +241,7 @@ def test_streaming_apply_patch_tracker_skips_dry_run(tmp_path: Path) -> None:
             "call_id": "call-patch",
             "name": "apply_patch",
             "arguments_delta": (
-                '{"dry_run":true,"patch":"*** Begin Patch\\n'
-                '*** Add File: dry.md\\n'
-                '+preview\\n'
+                '{"dry_run":true,"edits":[{"path":"dry.md","action":"add","new_text":"preview"}]}'
             ),
         })