feat: add remote diff and patch commands

coding-agent/src/coding_agent/__main__.py

@@ -909,6 +909,63 @@ def remote_workspaces_rm(name: str, workspace_id: str) -> None:
     click.echo(f"Cleaned workspace {workspace_id}")
 
 
+@remote.command("diff")
+@click.argument("name")
+@click.option("--session", "session_id", required=True, help="Remote session ID")
+def remote_diff(name: str, session_id: str) -> None:
+    """Show changed files for a remote session workspace."""
+    from coding_agent.remote.client import download_workspace_diff, get_remote
+
+    endpoint = get_remote(name)
+    diff = download_workspace_diff(endpoint, session_id)
+    files = diff.get("files")
+    if not isinstance(files, list):
+        raise click.ClickException("Remote workspace diff response missing files")
+    workspace_id = diff.get("workspace_id")
+    workspace_label = workspace_id if isinstance(workspace_id, str) else "unknown"
+    additions = diff.get("additions")
+    deletions = diff.get("deletions")
+    if not isinstance(additions, int) or not isinstance(deletions, int):
+        raise click.ClickException("Remote workspace diff response missing totals")
+
+    click.echo(
+        f"Remote workspace {workspace_label}: {len(files)} files changed, +{additions}/-{deletions}"
+    )
+    for raw_file in files:
+        if not isinstance(raw_file, dict):
+            raise click.ClickException("Remote workspace diff file entry is invalid")
+        path = raw_file.get("path")
+        status = raw_file.get("status")
+        if not isinstance(path, str) or not isinstance(status, str):
+            raise click.ClickException("Remote workspace diff file entry is invalid")
+        old_path = raw_file.get("old_path")
+        display_path = (
+            f"{old_path} -> {path}" if isinstance(old_path, str) and old_path else path
+        )
+        if raw_file.get("binary") is True:
+            change_summary = "binary"
+        else:
+            file_additions = raw_file.get("additions")
+            file_deletions = raw_file.get("deletions")
+            if isinstance(file_additions, int) and isinstance(file_deletions, int):
+                change_summary = f"+{file_additions}/-{file_deletions}"
+            else:
+                change_summary = "+?/-?"
+        click.echo(f"{status.ljust(9)} {display_path}  {change_summary}")
+
+
+@remote.command("patch")
+@click.argument("name")
+@click.option("--session", "session_id", required=True, help="Remote session ID")
+def remote_patch(name: str, session_id: str) -> None:
+    """Print a unified patch for a remote session workspace."""
+    from coding_agent.remote.client import download_workspace_patch, get_remote
+
+    endpoint = get_remote(name)
+    patch = download_workspace_patch(endpoint, session_id)
+    click.echo(patch, nl=False)
+
+
 @remote.command("download")
 @click.argument("name")
 @click.option("--session", "session_id", required=True, help="Remote session ID")

coding-agent/src/coding_agent/remote/client.py

@@ -175,7 +175,7 @@ def get_remote_session(endpoint: RemoteEndpoint, session_id: str) -> dict[str, o
         f"/sessions/{session_id}",
         "get remote session",
     )
-    return dict(data)
+    return data
 
 
 def cancel_remote_session(
@@ -269,6 +269,39 @@ def download_workspace_archive(
     return archive_base64
 
 
+def download_workspace_diff(
+    endpoint: RemoteEndpoint, session_id: str
+) -> dict[str, object]:
+    data = _get_remote_json(
+        endpoint,
+        f"/sessions/{session_id}/workspace/diff",
+        "download remote workspace diff",
+    )
+    files = data.get("files")
+    additions = data.get("additions")
+    deletions = data.get("deletions")
+    if not isinstance(files, list):
+        raise click.ClickException("Remote workspace diff response missing files")
+    if not isinstance(additions, int) or not isinstance(deletions, int):
+        raise click.ClickException("Remote workspace diff response missing totals")
+    return dict(data)
+
+
+def download_workspace_patch(endpoint: RemoteEndpoint, session_id: str) -> str:
+    data = _get_remote_json(
+        endpoint,
+        f"/sessions/{session_id}/workspace/patch",
+        "download remote workspace patch",
+    )
+    patch_format = data.get("format")
+    patch = data.get("patch")
+    if patch_format != "unified_diff":
+        raise click.ClickException("Remote workspace patch response has invalid format")
+    if not isinstance(patch, str):
+        raise click.ClickException("Remote workspace patch response missing patch")
+    return patch
+
+
 def _get_remote_json(
     endpoint: RemoteEndpoint,
     path: str,

coding-agent/tests/cli/test_remote_client.py

@@ -940,6 +940,136 @@ def test_remote_repl_requires_repo_or_empty_workspace(
     )
 
 
+def test_remote_diff_prints_changed_files(tmp_path: Path, monkeypatch) -> None:
+    config_path = tmp_path / "remotes.json"
+    monkeypatch.setenv("CODING_AGENT_REMOTES_FILE", str(config_path))
+    runner = CliRunner()
+    runner.invoke(
+        main,
+        ["remote", "add", "dev", "http://agent.example", "--token", "secret-token"],
+        catch_exceptions=False,
+    )
+    calls: list[tuple[str, dict[str, str]]] = []
+
+    class FakeResponse:
+        def raise_for_status(self) -> None:
+            return None
+
+        def json(self) -> dict[str, object]:
+            return {
+                "workspace_id": "ws-123",
+                "additions": 7,
+                "deletions": 2,
+                "files": [
+                    {
+                        "path": "src/app.py",
+                        "status": "modified",
+                        "old_path": None,
+                        "additions": 2,
+                        "deletions": 1,
+                        "binary": False,
+                    },
+                    {
+                        "path": "new.bin",
+                        "status": "added",
+                        "old_path": None,
+                        "additions": None,
+                        "deletions": None,
+                        "binary": True,
+                    },
+                ],
+            }
+
+    class FakeClient:
+        def __init__(self, **kwargs: object) -> None:
+            headers = kwargs.get("headers")
+            self.headers = headers if isinstance(headers, dict) else {}
+
+        def __enter__(self) -> FakeClient:
+            return self
+
+        def __exit__(self, exc_type: object, exc: object, tb: object) -> None:
+            return None
+
+        def get(self, path: str) -> FakeResponse:
+            calls.append((path, self.headers))
+            return FakeResponse()
+
+    monkeypatch.setattr("coding_agent.remote.client.httpx.Client", FakeClient)
+
+    result = runner.invoke(
+        main,
+        ["remote", "diff", "dev", "--session", "sess-123"],
+        catch_exceptions=False,
+    )
+
+    assert result.exit_code == 0
+    assert "Remote workspace ws-123: 2 files changed, +7/-2" in result.output
+    assert "modified  src/app.py  +2/-1" in result.output
+    assert "added     new.bin  binary" in result.output
+    assert calls == [
+        (
+            "/sessions/sess-123/workspace/diff",
+            {"Authorization": "Bearer secret-token"},
+        )
+    ]
+
+
+def test_remote_patch_prints_unified_diff(tmp_path: Path, monkeypatch) -> None:
+    config_path = tmp_path / "remotes.json"
+    monkeypatch.setenv("CODING_AGENT_REMOTES_FILE", str(config_path))
+    runner = CliRunner()
+    runner.invoke(
+        main,
+        ["remote", "add", "dev", "http://agent.example", "--token", "secret-token"],
+        catch_exceptions=False,
+    )
+    calls: list[tuple[str, dict[str, str]]] = []
+
+    class FakeResponse:
+        def raise_for_status(self) -> None:
+            return None
+
+        def json(self) -> dict[str, object]:
+            return {
+                "workspace_id": "ws-123",
+                "format": "unified_diff",
+                "patch": "diff --git a/README.md b/README.md\n+hello\n",
+            }
+
+    class FakeClient:
+        def __init__(self, **kwargs: object) -> None:
+            headers = kwargs.get("headers")
+            self.headers = headers if isinstance(headers, dict) else {}
+
+        def __enter__(self) -> FakeClient:
+            return self
+
+        def __exit__(self, exc_type: object, exc: object, tb: object) -> None:
+            return None
+
+        def get(self, path: str) -> FakeResponse:
+            calls.append((path, self.headers))
+            return FakeResponse()
+
+    monkeypatch.setattr("coding_agent.remote.client.httpx.Client", FakeClient)
+
+    result = runner.invoke(
+        main,
+        ["remote", "patch", "dev", "--session", "sess-123"],
+        catch_exceptions=False,
+    )
+
+    assert result.exit_code == 0
+    assert result.output == "diff --git a/README.md b/README.md\n+hello\n"
+    assert calls == [
+        (
+            "/sessions/sess-123/workspace/patch",
+            {"Authorization": "Bearer secret-token"},
+        )
+    ]
+
+
 def test_remote_repl_with_repo_uploads_snapshot_and_downloads_workspace(
     tmp_path: Path, monkeypatch
 ) -> None: