feat: improved document, folder mentions rendering

surfsense_backend/app/agents/new_chat/context.py

@@ -46,6 +46,10 @@ class SurfSenseContextSchema:
             Read by ``KnowledgePriorityMiddleware`` to seed its priority
             list. Stays out of the compiled-agent cache key — that's the
             whole point of putting it here.
+        mentioned_folder_ids: KB folders the user @-mentioned this turn
+            (cloud filesystem mode). Surfaced as ``[USER-MENTIONED]``
+            entries in ``<priority_documents>`` so the agent prioritises
+            walking those folders with ``ls`` / ``find_documents``.
         file_operation_contract: One-shot file operation contract emitted
             by ``FileIntentMiddleware`` for the upcoming turn.
         turn_id / request_id: Correlation IDs surfaced by the streaming
@@ -59,6 +63,7 @@ class SurfSenseContextSchema:
 
     search_space_id: int | None = None
     mentioned_document_ids: list[int] = field(default_factory=list)
+    mentioned_folder_ids: list[int] = field(default_factory=list)
     file_operation_contract: FileOperationContractState | None = None
     turn_id: str | None = None
     request_id: str | None = None

surfsense_backend/app/agents/new_chat/mention_resolver.py

@@ -0,0 +1,281 @@
+"""Resolve @-mention chips to canonical virtual paths and substitute the
+user-visible ``@title`` tokens with backtick-wrapped paths in the prompt
+the agent sees.
+
+The frontend's mention seam is a single discriminated-union list of
+``{kind: "doc" | "folder", id, title, document_type?}`` chips (see
+``surfsense_web/atoms/chat/mentioned-documents.atom.ts``). When a turn
+reaches the backend stream task we have three needs that this module
+centralises:
+
+1. Map each chip to its canonical virtual path
+   (``/documents/.../file.xml`` for docs, ``/documents/MyFolder/`` for
+   folders) so the agent sees concrete filesystem locations instead of
+   ambiguous ``@``-titles.
+2. Substitute ``@title`` tokens in the user-typed text with backtick-
+   wrapped paths so the path becomes part of the ``HumanMessage`` body
+   the LLM consumes — without rewriting the persisted user message
+   text (which keeps ``@title`` so chip rendering on reload is
+   unchanged).
+3. Surface the resolved id sets (docs + folders) to the priority
+   middleware so it can render ``[USER-MENTIONED]`` priority entries
+   without re-doing path resolution.
+
+This is intentionally one module — see the architectural note in
+``mention-paths-and-folders`` plan: previously the doc-resolution lived
+inline in ``stream_new_chat`` and the folder mention had no resolution
+at all. Centralising both behind a single ``resolve_mentions`` call
+turns a leaky multi-field seam into a single deeper interface.
+"""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass, field
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.agents.new_chat.path_resolver import (
+    DOCUMENTS_ROOT,
+    build_path_index,
+    doc_to_virtual_path,
+)
+from app.db import Document, Folder
+from app.schemas.new_chat import MentionedDocumentInfo
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass(frozen=True)
+class ResolvedMention:
+    """Canonical view of a single @-mention chip.
+
+    ``virtual_path`` is the path the agent will see (no trailing slash
+    for documents, trailing ``/`` for folders to match the convention
+    used by ``KnowledgeTreeMiddleware``).
+    """
+
+    kind: str  # "doc" | "folder"
+    id: int
+    title: str
+    virtual_path: str
+
+
+@dataclass
+class ResolvedMentionSet:
+    """Aggregate result of resolving a turn's mention chips.
+
+    ``token_to_path`` maps ``@title`` (the literal token the user typed
+    and the editor emitted) to the canonical virtual path for that
+    chip. It is produced longest-token-first so substitution mirrors
+    ``parseMentionSegments`` on the frontend (a longer title like
+    ``@Project Roadmap`` is never shadowed by a shorter prefix
+    ``@Project``).
+
+    ``mentioned_document_ids`` collapses doc + surfsense_doc chips into
+    a single ordered, deduped list because the priority middleware
+    treats them uniformly downstream — see
+    ``KnowledgePriorityMiddleware._compute_priority_paths``.
+    """
+
+    mentions: list[ResolvedMention] = field(default_factory=list)
+    token_to_path: list[tuple[str, str]] = field(default_factory=list)
+    mentioned_document_ids: list[int] = field(default_factory=list)
+    mentioned_folder_ids: list[int] = field(default_factory=list)
+
+
+def _folder_virtual_path(folder_id: int, folder_paths: dict[int, str]) -> str:
+    """Return ``/documents/Folder/Sub/`` for a folder id.
+
+    Falls back to the documents root when the folder is missing from
+    the index (deleted or in a different search space). Trailing slash
+    matches ``KnowledgeTreeMiddleware`` (``/documents/MyFolder/``) so
+    the agent's ``ls`` can dispatch on it as a directory.
+    """
+    base = folder_paths.get(folder_id, DOCUMENTS_ROOT)
+    return f"{base}/" if not base.endswith("/") else base
+
+
+async def resolve_mentions(
+    session: AsyncSession,
+    *,
+    search_space_id: int,
+    mentioned_documents: list[MentionedDocumentInfo] | None,
+    mentioned_document_ids: list[int] | None = None,
+    mentioned_surfsense_doc_ids: list[int] | None = None,
+    mentioned_folder_ids: list[int] | None = None,
+) -> ResolvedMentionSet:
+    """Resolve every @-mention chip on a turn into virtual paths.
+
+    The function takes both the ``mentioned_documents`` discriminated
+    list (chip metadata used for substitution + persistence) and the
+    parallel id arrays (``mentioned_document_ids``,
+    ``mentioned_surfsense_doc_ids``, ``mentioned_folder_ids``) for two
+    reasons:
+
+    * Legacy clients that haven't migrated to the unified chip list
+      still send the id arrays — we treat the union as authoritative.
+    * The id arrays are the canonical input to
+      ``KnowledgePriorityMiddleware`` (via ``SurfSenseContextSchema``);
+      returning the deduped, validated lists lets the route forward
+      them unchanged.
+
+    Resolution is best-effort: a chip whose id no longer exists (e.g.
+    document was deleted between mention and submit) is silently
+    dropped. The agent still sees the user's original text, just
+    without a backtick-path substitution for that chip.
+    """
+    chip_doc_ids: list[int] = []
+    chip_folder_ids: list[int] = []
+    chip_titles_by_id: dict[tuple[str, int], str] = {}
+    if mentioned_documents:
+        for chip in mentioned_documents:
+            kind = chip.kind
+            if kind == "folder":
+                chip_folder_ids.append(chip.id)
+            else:
+                chip_doc_ids.append(chip.id)
+            chip_titles_by_id[(kind, chip.id)] = chip.title
+
+    doc_id_pool: list[int] = list(
+        dict.fromkeys(
+            [
+                *(mentioned_document_ids or []),
+                *(mentioned_surfsense_doc_ids or []),
+                *chip_doc_ids,
+            ]
+        )
+    )
+    folder_id_pool: list[int] = list(
+        dict.fromkeys([*(mentioned_folder_ids or []), *chip_folder_ids])
+    )
+
+    if not doc_id_pool and not folder_id_pool:
+        return ResolvedMentionSet()
+
+    index = await build_path_index(session, search_space_id)
+
+    doc_rows: dict[int, Document] = {}
+    if doc_id_pool:
+        result = await session.execute(
+            select(Document).where(
+                Document.search_space_id == search_space_id,
+                Document.id.in_(doc_id_pool),
+            )
+        )
+        for row in result.scalars().all():
+            doc_rows[row.id] = row
+
+    folder_rows: dict[int, Folder] = {}
+    if folder_id_pool:
+        result = await session.execute(
+            select(Folder).where(
+                Folder.search_space_id == search_space_id,
+                Folder.id.in_(folder_id_pool),
+            )
+        )
+        for row in result.scalars().all():
+            folder_rows[row.id] = row
+
+    resolved: list[ResolvedMention] = []
+    accepted_doc_ids: list[int] = []
+    accepted_folder_ids: list[int] = []
+
+    for doc_id in doc_id_pool:
+        row = doc_rows.get(doc_id)
+        if row is None:
+            logger.debug(
+                "mention_resolver: dropping doc id=%s (not found in space=%s)",
+                doc_id,
+                search_space_id,
+            )
+            continue
+        title = chip_titles_by_id.get(("doc", doc_id), str(row.title or ""))
+        path = doc_to_virtual_path(
+            doc_id=row.id,
+            title=str(row.title or "untitled"),
+            folder_id=row.folder_id,
+            index=index,
+        )
+        resolved.append(
+            ResolvedMention(kind="doc", id=row.id, title=title, virtual_path=path)
+        )
+        accepted_doc_ids.append(row.id)
+
+    for folder_id in folder_id_pool:
+        row = folder_rows.get(folder_id)
+        if row is None:
+            logger.debug(
+                "mention_resolver: dropping folder id=%s (not found in space=%s)",
+                folder_id,
+                search_space_id,
+            )
+            continue
+        title = chip_titles_by_id.get(("folder", folder_id), str(row.name or ""))
+        path = _folder_virtual_path(row.id, index.folder_paths)
+        resolved.append(
+            ResolvedMention(kind="folder", id=row.id, title=title, virtual_path=path)
+        )
+        accepted_folder_ids.append(row.id)
+
+    token_to_path: list[tuple[str, str]] = []
+    seen_tokens: set[str] = set()
+    for mention in resolved:
+        if not mention.title:
+            continue
+        token = f"@{mention.title}"
+        if token in seen_tokens:
+            continue
+        seen_tokens.add(token)
+        token_to_path.append((token, mention.virtual_path))
+    token_to_path.sort(key=lambda pair: len(pair[0]), reverse=True)
+
+    return ResolvedMentionSet(
+        mentions=resolved,
+        token_to_path=token_to_path,
+        mentioned_document_ids=accepted_doc_ids,
+        mentioned_folder_ids=accepted_folder_ids,
+    )
+
+
+def substitute_in_text(text: str, token_to_path: list[tuple[str, str]]) -> str:
+    """Replace each ``@title`` token with a backtick-wrapped virtual path.
+
+    Mirrors ``parseMentionSegments`` on the frontend: longest token
+    first, single forward pass, no regex (titles can contain regex
+    metacharacters). The substitution is idempotent for already-
+    substituted text because the backtick-wrapped path no longer
+    starts with ``@``.
+
+    Empty / no-op cases short-circuit so callers can pass this through
+    unconditionally without paying for a scan.
+    """
+    if not text or not token_to_path:
+        return text
+
+    out: list[str] = []
+    i = 0
+    n = len(text)
+    while i < n:
+        matched: tuple[str, str] | None = None
+        for token, path in token_to_path:
+            if text.startswith(token, i):
+                matched = (token, path)
+                break
+        if matched is None:
+            out.append(text[i])
+            i += 1
+            continue
+        token, path = matched
+        out.append(f"`{path}`")
+        i += len(token)
+    return "".join(out)
+
+
+__all__ = [
+    "ResolvedMention",
+    "ResolvedMentionSet",
+    "resolve_mentions",
+    "substitute_in_text",
+]

surfsense_backend/app/agents/new_chat/middleware/knowledge_search.py

@@ -54,6 +54,7 @@ from app.db import (
     NATIVE_TO_LEGACY_DOCTYPE,
     Chunk,
     Document,
+    Folder,
     shielded_async_session,
 )
 from app.retriever.chunks_hybrid_search import ChucksHybridSearchRetriever
@@ -832,6 +833,22 @@ class KnowledgePriorityMiddleware(AgentMiddleware):  # type: ignore[type-arg]
             mention_ids = list(self.mentioned_document_ids)
             self.mentioned_document_ids = []
 
+        # Folder mentions live alongside doc mentions on the runtime
+        # context. They never feed hybrid search (folders aren't
+        # embedded) — they're surfaced purely as ``[USER-MENTIONED]``
+        # priority entries so the agent walks the folder with ``ls`` /
+        # ``find_documents`` instead of ignoring it. Cloud filesystem
+        # mode only.
+        folder_mention_ids: list[int] = []
+        if (
+            ctx is not None
+            and getattr(self, "filesystem_mode", FilesystemMode.CLOUD)
+            == FilesystemMode.CLOUD
+        ):
+            ctx_folders = getattr(ctx, "mentioned_folder_ids", None)
+            if ctx_folders:
+                folder_mention_ids = list(ctx_folders)
+
         mentioned_results: list[dict[str, Any]] = []
         if mention_ids:
             mentioned_results = await fetch_mentioned_documents(
@@ -876,16 +893,21 @@ class KnowledgePriorityMiddleware(AgentMiddleware):  # type: ignore[type-arg]
 
         priority, matched_chunk_ids = await self._materialize_priority(merged)
 
+        if folder_mention_ids:
+            folder_entries = await self._materialize_folder_priority(folder_mention_ids)
+            priority = folder_entries + priority
+
         new_messages = list(messages)
         insert_at = max(len(new_messages) - 1, 0)
         new_messages.insert(insert_at, _render_priority_message(priority))
 
         _perf_log.info(
-            "[kb_priority] completed in %.3fs query=%r priority=%d mentioned=%d",
+            "[kb_priority] completed in %.3fs query=%r priority=%d mentioned=%d folders=%d",
             asyncio.get_event_loop().time() - t0,
             user_text[:80],
             len(priority),
             len(mentioned_results),
+            len(folder_mention_ids),
         )
 
         return {
@@ -894,6 +916,58 @@ class KnowledgePriorityMiddleware(AgentMiddleware):  # type: ignore[type-arg]
             "messages": new_messages,
         }
 
+    async def _materialize_folder_priority(
+        self, folder_ids: list[int]
+    ) -> list[dict[str, Any]]:
+        """Resolve user-mentioned folder ids to ``<priority_documents>`` entries.
+
+        Each entry uses the canonical ``/documents/Folder/Sub/`` virtual
+        path (matching ``KnowledgeTreeMiddleware`` and the agent's
+        ``ls`` adapter) and is flagged ``mentioned=True`` so the
+        rendered line carries ``[USER-MENTIONED]``. ``score`` is left
+        ``None`` so the renderer prints ``n/a`` — folders aren't
+        ranked, the agent decides which children to read.
+        """
+        if not folder_ids:
+            return []
+        async with shielded_async_session() as session:
+            index: PathIndex = await build_path_index(session, self.search_space_id)
+            folder_rows = await session.execute(
+                select(Folder.id, Folder.name).where(
+                    Folder.search_space_id == self.search_space_id,
+                    Folder.id.in_(folder_ids),
+                )
+            )
+            folder_titles: dict[int, str] = {
+                row.id: row.name for row in folder_rows.all()
+            }
+
+        entries: list[dict[str, Any]] = []
+        seen: set[int] = set()
+        for folder_id in folder_ids:
+            if folder_id in seen:
+                continue
+            seen.add(folder_id)
+            base = index.folder_paths.get(folder_id)
+            if base is None:
+                logger.debug(
+                    "kb_priority: dropping folder id=%s (missing from path index)",
+                    folder_id,
+                )
+                continue
+            path = base if base.endswith("/") else f"{base}/"
+            entries.append(
+                {
+                    "path": path,
+                    "score": None,
+                    "document_id": None,
+                    "folder_id": folder_id,
+                    "title": folder_titles.get(folder_id, ""),
+                    "mentioned": True,
+                }
+            )
+        return entries
+
     async def _materialize_priority(
         self, merged: list[dict[str, Any]]
     ) -> tuple[list[dict[str, Any]], dict[int, list[int]]]:

surfsense_backend/app/routes/documents_routes.py

@@ -7,6 +7,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.future import select
 from sqlalchemy.orm import selectinload
 
+from app.agents.new_chat.path_resolver import virtual_path_to_doc
 from app.db import (
     Chunk,
     Document,
@@ -752,7 +753,24 @@ async def get_document_by_virtual_path(
     session: AsyncSession = Depends(get_async_session),
     user: User = Depends(current_active_user),
 ):
-    """Resolve a knowledge-base document id by exact virtual path."""
+    """Resolve a knowledge-base document by its agent-facing virtual path.
+
+    The agent renders every document under ``/documents/...`` with a
+    ``.xml`` extension appended via ``safe_filename`` (so a PDF titled
+    ``2025-W2.pdf`` becomes ``/documents/2025-W2.pdf.xml``). When the user
+    clicks that path in an answer, this endpoint must round-trip back to
+    the underlying ``Document`` row regardless of its type — agent-created
+    NOTE docs (which carry ``virtual_path`` in metadata), uploaded PDFs,
+    and connector docs all flow through here.
+
+    Resolution is delegated to :func:`virtual_path_to_doc`, the single
+    source of truth that handles:
+
+    * ``unique_identifier_hash`` lookup (agent NOTE fast path)
+    * ``" (<doc_id>).xml"`` disambiguation suffixes
+    * ``.xml`` extension stripping for title-based fallback
+    * ``safe_filename`` round-trip for connector titles with lossy chars
+    """
     try:
         await check_permission(
             session,
@@ -762,24 +780,19 @@ async def get_document_by_virtual_path(
             "You don't have permission to read documents in this search space",
         )
 
-        result = await session.execute(
-            select(
-                Document.id,
-                Document.title,
-                Document.document_type,
-            ).filter(
-                Document.search_space_id == search_space_id,
-                Document.document_metadata["virtual_path"].as_string() == virtual_path,
-            )
+        document = await virtual_path_to_doc(
+            session,
+            search_space_id=search_space_id,
+            virtual_path=virtual_path,
         )
-        row = result.first()
-        if row is None:
+        if document is None:
             raise HTTPException(status_code=404, detail="Document not found")
 
         return DocumentTitleRead(
-            id=row.id,
-            title=row.title,
-            document_type=row.document_type,
+            id=document.id,
+            title=document.title,
+            document_type=document.document_type,
+            folder_id=document.folder_id,
         )
     except HTTPException:
         raise

surfsense_backend/app/routes/new_chat_routes.py

@@ -1781,6 +1781,7 @@ async def handle_new_chat(
                 llm_config_id=llm_config_id,
                 mentioned_document_ids=request.mentioned_document_ids,
                 mentioned_surfsense_doc_ids=request.mentioned_surfsense_doc_ids,
+                mentioned_folder_ids=request.mentioned_folder_ids,
                 mentioned_documents=mentioned_documents_payload,
                 needs_history_bootstrap=thread.needs_history_bootstrap,
                 thread_visibility=thread.visibility,
@@ -2266,6 +2267,7 @@ async def regenerate_response(
                     llm_config_id=llm_config_id,
                     mentioned_document_ids=request.mentioned_document_ids,
                     mentioned_surfsense_doc_ids=request.mentioned_surfsense_doc_ids,
+                    mentioned_folder_ids=request.mentioned_folder_ids,
                     mentioned_documents=mentioned_documents_payload,
                     checkpoint_id=target_checkpoint_id,
                     needs_history_bootstrap=thread.needs_history_bootstrap,

surfsense_backend/app/schemas/new_chat.py

@@ -201,18 +201,34 @@ class NewChatUserImagePart(BaseModel):
 
 
 class MentionedDocumentInfo(BaseModel):
-    """Display metadata for a single ``@``-mentioned document.
+    """Display metadata for a single ``@``-mention chip.
 
-    The full triple ``{id, title, document_type}`` is forwarded by the
-    frontend mention chip so the server can embed it in the persisted
-    user message ``ContentPart[]`` (single ``mentioned-documents`` part).
-    The history loader then renders the chips on reload without an extra
+    Carries either a knowledge-base document or a knowledge-base folder
+    (discriminated by ``kind``). The full triple
+    ``{id, title, document_type}`` is forwarded by the frontend mention
+    chip so the server can embed it in the persisted user message
+    ``ContentPart[]`` (single ``mentioned-documents`` part). The
+    history loader then renders the chips on reload without an extra
     fetch — mirrors the pre-refactor frontend ``persistUserTurn`` shape.
+
+    ``kind`` defaults to ``"doc"`` so legacy clients and persisted rows
+    that predate folder mentions deserialise unchanged.
     """
 
     id: int
     title: str = Field(..., min_length=1, max_length=500)
     document_type: str = Field(..., min_length=1, max_length=100)
+    kind: Literal["doc", "folder"] = Field(
+        default="doc",
+        description=(
+            "Discriminator for the chip's referent: ``doc`` is a "
+            "knowledge-base ``Document`` row, ``folder`` is a "
+            "knowledge-base ``Folder`` row. Folders carry the sentinel "
+            "``document_type='FOLDER'`` to keep the frontend dedup key "
+            "``(kind:document_type:id)`` from colliding doc and folder "
+            "ids that happen to share an integer value."
+        ),
+    )
 
 
 class NewChatRequest(BaseModel):
@@ -228,15 +244,26 @@ class NewChatRequest(BaseModel):
     mentioned_surfsense_doc_ids: list[int] | None = (
         None  # Optional SurfSense documentation IDs mentioned with @ in the chat
     )
+    mentioned_folder_ids: list[int] | None = Field(
+        default=None,
+        description=(
+            "Optional knowledge-base folder IDs the user mentioned with "
+            "@. Resolved to virtual paths (``/documents/.../``) by "
+            "``mention_resolver`` and surfaced to the agent via "
+            "(a) backtick-wrapped substitution in ``user_query`` and "
+            "(b) a ``[USER-MENTIONED]`` entry in ``<priority_documents>``. "
+            "The agent's ``ls`` tool can then walk the folder itself."
+        ),
+    )
     mentioned_documents: list[MentionedDocumentInfo] | None = Field(
         default=None,
         description=(
-            "Display metadata (id, title, document_type) for every "
-            "@-mentioned document. Persisted as a ``mentioned-documents`` "
-            "ContentPart on the user message so reload renders chips "
-            "without an extra fetch. Optional and additive — when None "
-            "the user message is persisted without a mentioned-documents "
-            "part."
+            "Display metadata (id, title, document_type, kind) for every "
+            "@-mention chip — both documents and folders. Persisted as a "
+            "``mentioned-documents`` ContentPart on the user message so "
+            "reload renders chips without an extra fetch. Optional and "
+            "additive — when None the user message is persisted without "
+            "a mentioned-documents part."
         ),
     )
     disabled_tools: list[str] | None = (
@@ -290,14 +317,22 @@ class RegenerateRequest(BaseModel):
     )
     mentioned_document_ids: list[int] | None = None
     mentioned_surfsense_doc_ids: list[int] | None = None
+    mentioned_folder_ids: list[int] | None = Field(
+        default=None,
+        description=(
+            "Optional knowledge-base folder IDs the user mentioned with "
+            "@ on the edited user turn. Only used when ``user_query`` is "
+            "non-None (edit). Mirrors ``NewChatRequest.mentioned_folder_ids``."
+        ),
+    )
     mentioned_documents: list[MentionedDocumentInfo] | None = Field(
         default=None,
         description=(
-            "Display metadata (id, title, document_type) for every "
-            "@-mentioned document on the edited user turn. Only used "
-            "when ``user_query`` is non-None (edit). Persisted as a "
-            "``mentioned-documents`` ContentPart on the new user "
-            "message. None means no chip metadata."
+            "Display metadata (id, title, document_type, kind) for every "
+            "@-mention chip on the edited user turn — both documents and "
+            "folders. Only used when ``user_query`` is non-None (edit). "
+            "Persisted as a ``mentioned-documents`` ContentPart on the "
+            "new user message. None means no chip metadata."
         ),
     )
     disabled_tools: list[str] | None = None
@@ -373,6 +408,16 @@ class ResumeRequest(BaseModel):
     filesystem_mode: Literal["cloud", "desktop_local_folder"] = "cloud"
     client_platform: Literal["web", "desktop"] = "web"
     local_filesystem_mounts: list[LocalFilesystemMountPayload] | None = None
+    mentioned_folder_ids: list[int] | None = Field(
+        default=None,
+        description=(
+            "Forwarded for symmetry with /new_chat and /regenerate. "
+            "Resume reuses the original interrupted user turn so this "
+            "field is informational only — the originating turn's "
+            "folder mentions already shaped the priority hints baked "
+            "into the agent's checkpoint."
+        ),
+    )
     mentioned_documents: list[MentionedDocumentInfo] | None = Field(
         default=None,
         description=(

surfsense_backend/app/services/streaming/emitter/registry.py

@@ -43,9 +43,7 @@ class EmitterRegistry:
         return main_emitter()
 
     def has_active_subagents(self) -> bool:
-        return any(
-            emitter.level == "subagent" for emitter in self._by_run_id.values()
-        )
+        return any(emitter.level == "subagent" for emitter in self._by_run_id.values())
 
     def clear(self) -> None:
         self._by_run_id.clear()

surfsense_backend/app/services/streaming/events/reasoning.py

@@ -6,9 +6,7 @@ from ..emitter import Emitter, attach_emitted_by
 from ..envelope import format_sse
 
 
-def format_reasoning_start(
-    reasoning_id: str, *, emitter: Emitter | None = None
-) -> str:
+def format_reasoning_start(reasoning_id: str, *, emitter: Emitter | None = None) -> str:
     return format_sse(
         attach_emitted_by({"type": "reasoning-start", "id": reasoning_id}, emitter)
     )
@@ -28,9 +26,7 @@ def format_reasoning_delta(
     )
 
 
-def format_reasoning_end(
-    reasoning_id: str, *, emitter: Emitter | None = None
-) -> str:
+def format_reasoning_end(reasoning_id: str, *, emitter: Emitter | None = None) -> str:
     return format_sse(
         attach_emitted_by({"type": "reasoning-end", "id": reasoning_id}, emitter)
     )

surfsense_backend/app/services/streaming/events/text.py

@@ -7,9 +7,7 @@ from ..envelope import format_sse
 
 
 def format_text_start(text_id: str, *, emitter: Emitter | None = None) -> str:
-    return format_sse(
-        attach_emitted_by({"type": "text-start", "id": text_id}, emitter)
-    )
+    return format_sse(attach_emitted_by({"type": "text-start", "id": text_id}, emitter))
 
 
 def format_text_delta(
@@ -26,6 +24,4 @@ def format_text_delta(
 
 
 def format_text_end(text_id: str, *, emitter: Emitter | None = None) -> str:
-    return format_sse(
-        attach_emitted_by({"type": "text-end", "id": text_id}, emitter)
-    )
+    return format_sse(attach_emitted_by({"type": "text-end", "id": text_id}, emitter))

surfsense_backend/app/services/streaming/service.py

@@ -84,9 +84,7 @@ class StreamingService:
     def format_step_finish(self, *, emitter: Emitter | None = None) -> str:
         return lifecycle.format_step_finish(emitter=emitter)
 
-    def format_text_start(
-        self, text_id: str, *, emitter: Emitter | None = None
-    ) -> str:
+    def format_text_start(self, text_id: str, *, emitter: Emitter | None = None) -> str:
         return text.format_text_start(text_id, emitter=emitter)
 
     def format_text_delta(
@@ -94,9 +92,7 @@ class StreamingService:
     ) -> str:
         return text.format_text_delta(text_id, delta, emitter=emitter)
 
-    def format_text_end(
-        self, text_id: str, *, emitter: Emitter | None = None
-    ) -> str:
+    def format_text_end(self, text_id: str, *, emitter: Emitter | None = None) -> str:
         return text.format_text_end(text_id, emitter=emitter)
 
     def format_reasoning_start(

surfsense_backend/app/tasks/chat/content_builder.py

@@ -51,7 +51,9 @@ logger = logging.getLogger(__name__)
 _MEANINGFUL_PART_TYPES: frozenset[str] = frozenset({"text", "reasoning", "tool-call"})
 
 
-def _merge_tool_part_metadata(part: dict[str, Any], metadata: dict[str, Any] | None) -> None:
+def _merge_tool_part_metadata(
+    part: dict[str, Any], metadata: dict[str, Any] | None
+) -> None:
     """Shallow-merge ``metadata`` into ``part["metadata"]``; first key wins.
 
     Used for tool-call linkage (``spanId``, ``thinkingStepId``, …): a later

surfsense_backend/app/tasks/chat/persistence.py

@@ -109,17 +109,18 @@ def _build_user_content(
         [{"type": "text", "text": "..."},
          {"type": "image", "image": "data:..."},
          {"type": "mentioned-documents", "documents": [{"id": int,
-            "title": str, "document_type": str}, ...]}]
+            "title": str, "document_type": str, "kind": "doc" | "folder"},
+            ...]}]
 
     The companion reader is
     ``app.utils.user_message_multimodal.split_persisted_user_content_parts``
     which expects exactly this shape — keep them in sync.
 
-    ``mentioned_documents``: optional list of ``{id, title, document_type}``
-    dicts. When non-empty (and a ``mentioned-documents`` part is not already
-    in some other input shape), a single ``{"type": "mentioned-documents",
-    "documents": [...]}`` part is appended. Mirrors the FE injection at
-    ``page.tsx:281-286`` (``persistUserTurn``).
+    ``mentioned_documents``: optional list of mention chip dicts. Each
+    dict may include a ``kind`` discriminator (``"doc"`` or ``"folder"``)
+    so the persisted ContentPart round-trips folder chips on reload.
+    When ``kind`` is missing we default to ``"doc"`` so legacy clients
+    that haven't migrated to the union schema still persist correctly.
     """
     parts: list[dict[str, Any]] = [{"type": "text", "text": user_query or ""}]
     for url in user_image_data_urls or ():
@@ -135,11 +136,14 @@ def _build_user_content(
             document_type = doc.get("document_type")
             if doc_id is None or title is None or document_type is None:
                 continue
+            kind_raw = doc.get("kind", "doc")
+            kind = kind_raw if kind_raw in ("doc", "folder") else "doc"
             normalized.append(
                 {
                     "id": doc_id,
                     "title": str(title),
                     "document_type": str(document_type),
+                    "kind": kind,
                 }
             )
         if normalized:

surfsense_backend/app/tasks/chat/stream_new_chat.py

@@ -43,6 +43,7 @@ from app.agents.new_chat.memory_extraction import (
     extract_and_save_memory,
     extract_and_save_team_memory,
 )
+from app.agents.new_chat.mention_resolver import resolve_mentions, substitute_in_text
 from app.agents.new_chat.middleware.busy_mutex import (
     end_turn,
     get_cancel_state,
@@ -929,6 +930,7 @@ async def stream_new_chat(
     llm_config_id: int = -1,
     mentioned_document_ids: list[int] | None = None,
     mentioned_surfsense_doc_ids: list[int] | None = None,
+    mentioned_folder_ids: list[int] | None = None,
     mentioned_documents: list[dict[str, Any]] | None = None,
     checkpoint_id: str | None = None,
     needs_history_bootstrap: bool = False,
@@ -958,6 +960,7 @@ async def stream_new_chat(
         needs_history_bootstrap: If True, load message history from DB (for cloned chats)
         mentioned_document_ids: Optional list of document IDs mentioned with @ in the chat
         mentioned_surfsense_doc_ids: Optional list of SurfSense doc IDs mentioned with @ in the chat
+        mentioned_folder_ids: Optional list of knowledge-base folder IDs mentioned with @ (cloud mode)
         checkpoint_id: Optional checkpoint ID to rewind/fork from (for edit/reload operations)
 
     Yields:
@@ -1502,6 +1505,53 @@ async def stream_new_chat(
         )
         recent_reports = list(recent_reports_result.scalars().all())
 
+        # Resolve @-mention chips to canonical virtual paths and rewrite
+        # the user-typed text so the LLM sees ``\`/documents/...\``` instead
+        # of bare ``@title``. The persisted user-message text keeps
+        # ``@title`` so chip rendering on reload is unchanged — see
+        # ``persistence._build_user_content``.
+        #
+        # Cloud mode only: local-folder mode keeps the legacy
+        # ``@title`` text path; mention support there is a follow-up
+        # task because the path scheme (mount-rooted) and the picker
+        # UI both need separate work.
+        accepted_folder_ids: list[int] = []
+        if fs_mode == FilesystemMode.CLOUD.value and (
+            mentioned_document_ids
+            or mentioned_surfsense_doc_ids
+            or mentioned_folder_ids
+            or mentioned_documents
+        ):
+            from app.schemas.new_chat import (
+                MentionedDocumentInfo as _MentionedDocumentInfo,
+            )
+
+            chip_objs: list[_MentionedDocumentInfo] | None = None
+            if mentioned_documents:
+                chip_objs = []
+                for raw in mentioned_documents:
+                    if isinstance(raw, _MentionedDocumentInfo):
+                        chip_objs.append(raw)
+                        continue
+                    try:
+                        chip_objs.append(_MentionedDocumentInfo.model_validate(raw))
+                    except Exception:
+                        logger.debug(
+                            "stream_new_chat: dropping malformed mention chip %r",
+                            raw,
+                        )
+
+            resolved = await resolve_mentions(
+                session,
+                search_space_id=search_space_id,
+                mentioned_documents=chip_objs,
+                mentioned_document_ids=mentioned_document_ids,
+                mentioned_surfsense_doc_ids=mentioned_surfsense_doc_ids,
+                mentioned_folder_ids=mentioned_folder_ids,
+            )
+            user_query = substitute_in_text(user_query, resolved.token_to_path)
+            accepted_folder_ids = resolved.mentioned_folder_ids
+
         # Format the user query with context (SurfSense docs + reports only)
         final_query = user_query
         context_parts = []
@@ -1901,6 +1951,9 @@ async def stream_new_chat(
         runtime_context = SurfSenseContextSchema(
             search_space_id=search_space_id,
             mentioned_document_ids=list(mentioned_document_ids or []),
+            mentioned_folder_ids=list(
+                accepted_folder_ids or mentioned_folder_ids or []
+            ),
             request_id=request_id,
             turn_id=stream_result.turn_id,
         )

surfsense_backend/app/tasks/chat/streaming/handlers/custom_events.py

@@ -26,9 +26,7 @@ def handle_report_progress(
         return None, last_active_step_items
 
     phase = data.get("phase", "")
-    topic_items = [
-        item for item in last_active_step_items if item.startswith("Topic:")
-    ]
+    topic_items = [item for item in last_active_step_items if item.startswith("Topic:")]
 
     if phase in ("revising_section", "adding_section"):
         plan_items = [
@@ -56,7 +54,9 @@ def handle_report_progress(
     return frame, new_items
 
 
-def handle_document_created(data: dict[str, Any], *, streaming_service: Any) -> str | None:
+def handle_document_created(
+    data: dict[str, Any], *, streaming_service: Any
+) -> str | None:
     if not data.get("id"):
         return None
     return streaming_service.format_data(

surfsense_backend/app/tasks/chat/streaming/handlers/tool_end.py

@@ -13,7 +13,9 @@ from app.tasks.chat.streaming.handlers.tools import (
 )
 from app.tasks.chat.streaming.helpers.tool_output import tool_output_has_error
 from app.tasks.chat.streaming.relay.state import AgentEventRelayState
-from app.tasks.chat.streaming.relay.task_span import clear_task_span_if_delegating_task_ended
+from app.tasks.chat.streaming.relay.task_span import (
+    clear_task_span_if_delegating_task_ended,
+)
 from app.tasks.chat.streaming.relay.thinking_step_sse import emit_thinking_step_frame
 
 
@@ -32,9 +34,7 @@ def iter_tool_end_frames(
     run_id = event.get("run_id", "")
     tool_name = event.get("name", "unknown_tool")
     raw_output = event.get("data", {}).get("output", "")
-    staged_file_path = (
-        state.file_path_by_run.pop(run_id, None) if run_id else None
-    )
+    staged_file_path = state.file_path_by_run.pop(run_id, None) if run_id else None
 
     if tool_name == "update_memory":
         state.called_update_memory = True
@@ -116,6 +116,4 @@ def iter_tool_end_frames(
     )
     yield from iter_tool_completion_emission_frames(emission_ctx)
 
-    clear_task_span_if_delegating_task_ended(
-        state, tool_name=tool_name, run_id=run_id
-    )
+    clear_task_span_if_delegating_task_ended(state, tool_name=tool_name, run_id=run_id)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/connector/shared/thinking.py

@@ -15,7 +15,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     return default_thinking.resolve_completed_thinking(
         tool_name, tool_output, last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/deliverables/generate_image/thinking.py

@@ -23,7 +23,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/deliverables/generate_podcast/thinking.py

@@ -34,7 +34,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/deliverables/generate_report/thinking.py

@@ -29,7 +29,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items
@@ -44,9 +46,7 @@ def resolve_completed_thinking(
         else "Report"
     )
     word_count = (
-        tool_output.get("word_count", 0)
-        if isinstance(tool_output, dict)
-        else 0
+        tool_output.get("word_count", 0) if isinstance(tool_output, dict) else 0
     )
     is_revision = (
         tool_output.get("is_revision", False)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/deliverables/generate_resume/thinking.py

@@ -17,7 +17,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     return default_thinking.resolve_completed_thinking(
         tool_name, tool_output, last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/deliverables/generate_video_presentation/thinking.py

@@ -17,7 +17,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/deliverables/save_document/thinking.py

@@ -21,7 +21,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/edit_file/thinking.py

@@ -21,7 +21,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Editing file", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/execute/emission.py

@@ -24,9 +24,7 @@ def iter_completion_emission_frames(
         output_text = om.group(1) if om else ""
     thread_id_str = ctx.langgraph_config.get("configurable", {}).get("thread_id", "")
 
-    for sf_match in re.finditer(
-        r"^SANDBOX_FILE:\s*(.+)$", output_text, re.MULTILINE
-    ):
+    for sf_match in re.finditer(r"^SANDBOX_FILE:\s*(.+)$", output_text, re.MULTILINE):
         fpath = sf_match.group(1).strip()
         if fpath and fpath not in ctx.stream_result.sandbox_files:
             ctx.stream_result.sandbox_files.append(fpath)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/execute/thinking.py

@@ -22,7 +22,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/glob/thinking.py

@@ -21,7 +21,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Searching files", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/grep/thinking.py

@@ -25,7 +25,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Searching content", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/ls/thinking.py

@@ -20,7 +20,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     if isinstance(tool_output, dict):
@@ -38,9 +40,7 @@ def resolve_completed_thinking(
                 paths = [str(p) for p in parsed]
         except (ValueError, SyntaxError):
             paths = [
-                line.strip()
-                for line in ls_output.strip().split("\n")
-                if line.strip()
+                line.strip() for line in ls_output.strip().split("\n") if line.strip()
             ]
         for p in paths:
             name = p.rstrip("/").split("/")[-1]

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/mkdir/thinking.py

@@ -17,11 +17,15 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
     d = as_tool_input_dict(tool_input)
     p = d.get("path", "") if isinstance(tool_input, dict) else str(tool_input)
     display = p if len(p) <= 80 else "…" + p[-77:]
-    return ToolStartThinking(title="Creating folder", items=[display] if display else [])
+    return ToolStartThinking(
+        title="Creating folder", items=[display] if display else []
+    )
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Creating folder", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/move_file/thinking.py

@@ -27,7 +27,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Moving file", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/read_file/thinking.py

@@ -21,7 +21,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Reading file", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/rm/thinking.py

@@ -22,7 +22,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Deleting file", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/rmdir/thinking.py

@@ -17,11 +17,15 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
     d = as_tool_input_dict(tool_input)
     p = d.get("path", "") if isinstance(tool_input, dict) else str(tool_input)
     display = p if len(p) <= 80 else "…" + p[-77:]
-    return ToolStartThinking(title="Deleting folder", items=[display] if display else [])
+    return ToolStartThinking(
+        title="Deleting folder", items=[display] if display else []
+    )
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Deleting folder", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/write_file/thinking.py

@@ -21,7 +21,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Writing file", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/filesystem/write_todos/thinking.py

@@ -20,15 +20,15 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
     return ToolStartThinking(
         title="Planning tasks",
         items=(
-            [f"{todo_count} task{'s' if todo_count != 1 else ''}"]
-            if todo_count
-            else []
+            [f"{todo_count} task{'s' if todo_count != 1 else ''}"] if todo_count else []
         ),
     )
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_output, tool_name
     return ("Planning tasks", last_items)

surfsense_backend/app/tasks/chat/streaming/handlers/tools/registry.py

@@ -58,14 +58,18 @@ def _emission_module(tool_name: str) -> str:
 
 def _import_thinking(tool_name: str):
     try:
-        return importlib.import_module(f"{_BASE}.{_thinking_module(tool_name)}.thinking")
+        return importlib.import_module(
+            f"{_BASE}.{_thinking_module(tool_name)}.thinking"
+        )
     except ModuleNotFoundError:
         return importlib.import_module(f"{_BASE}.default.thinking")
 
 
 def _import_emission(tool_name: str):
     try:
-        return importlib.import_module(f"{_BASE}.{_emission_module(tool_name)}.emission")
+        return importlib.import_module(
+            f"{_BASE}.{_emission_module(tool_name)}.emission"
+        )
     except ModuleNotFoundError:
         return importlib.import_module(f"{_BASE}.default.emission")
 

surfsense_backend/app/tasks/chat/streaming/handlers/tools/scrape_webpage/thinking.py

@@ -23,7 +23,9 @@ def resolve_start_thinking(tool_name: str, tool_input: Any) -> ToolStartThinking
 
 
 def resolve_completed_thinking(
-    tool_name: str, tool_output: Any, last_items: list[str],
+    tool_name: str,
+    tool_output: Any,
+    last_items: list[str],
 ) -> tuple[str, list[str]]:
     del tool_name
     items = last_items

surfsense_backend/app/tasks/chat/streaming/handlers/tools/web_search/emission.py

@@ -28,11 +28,7 @@ def iter_completion_emission_frames(
         xml,
     ):
         chunk_url, content = m.group(1).strip(), m.group(2).strip()
-        if (
-            chunk_url.startswith("http")
-            and chunk_url in citations
-            and content
-        ):
+        if chunk_url.startswith("http") and chunk_url in citations and content:
             citations[chunk_url]["snippet"] = (
                 content[:200] + "…" if len(content) > 200 else content
             )

surfsense_backend/tests/integration/chat/test_persistence.py

@@ -367,18 +367,26 @@ class TestPersistUserTurn:
         db_thread,
         patched_shielded_session,
     ):
-        """The full ``{id, title, document_type}`` triple forwarded by
-        the FE must round-trip into a single ``mentioned-documents``
-        ContentPart on the persisted user message — the history loader
-        renders the chips on reload from this part directly.
+        """The full ``{id, title, document_type, kind}`` chip metadata
+        forwarded by the FE must round-trip into a single
+        ``mentioned-documents`` ContentPart on the persisted user
+        message — the history loader renders the chips on reload from
+        this part directly. Folder chips ride alongside doc chips so
+        the FE can render mixed mention bars without a second fetch.
         """
         thread_id = db_thread.id
         user_id_str = str(db_user.id)
         turn_id = f"{thread_id}:8200"
 
         mentioned = [
-            {"id": 11, "title": "Alpha", "document_type": "GENERAL"},
-            {"id": 22, "title": "Beta", "document_type": "GENERAL"},
+            {"id": 11, "title": "Alpha", "document_type": "GENERAL", "kind": "doc"},
+            {"id": 22, "title": "Beta", "document_type": "GENERAL", "kind": "doc"},
+            {
+                "id": 33,
+                "title": "Reports",
+                "document_type": "FOLDER",
+                "kind": "folder",
+            },
         ]
         msg_id = await persist_user_turn(
             chat_id=thread_id,
@@ -397,8 +405,61 @@ class TestPersistUserTurn:
         assert row.content[1] == {
             "type": "mentioned-documents",
             "documents": [
-                {"id": 11, "title": "Alpha", "document_type": "GENERAL"},
-                {"id": 22, "title": "Beta", "document_type": "GENERAL"},
+                {"id": 11, "title": "Alpha", "document_type": "GENERAL", "kind": "doc"},
+                {"id": 22, "title": "Beta", "document_type": "GENERAL", "kind": "doc"},
+                {
+                    "id": 33,
+                    "title": "Reports",
+                    "document_type": "FOLDER",
+                    "kind": "folder",
+                },
+            ],
+        }
+
+    async def test_legacy_chip_without_kind_defaults_to_doc(
+        self,
+        db_session,
+        db_user,
+        db_thread,
+        patched_shielded_session,
+    ):
+        """Pre-folder clients send chips without ``kind``. The persistence
+        layer defaults them to ``"doc"`` so the round-trip stays
+        consistent on reload — the FE schema's optional default
+        produces the same value, but persisting it explicitly keeps
+        the DB row self-describing.
+        """
+        thread_id = db_thread.id
+        user_id_str = str(db_user.id)
+        turn_id = f"{thread_id}:8201"
+
+        mentioned = [
+            {"id": 77, "title": "Legacy", "document_type": "GENERAL"},
+        ]
+        msg_id = await persist_user_turn(
+            chat_id=thread_id,
+            user_id=user_id_str,
+            turn_id=turn_id,
+            user_query="hi",
+            mentioned_documents=mentioned,
+        )
+        assert isinstance(msg_id, int)
+
+        row = await db_session.get(NewChatMessage, msg_id)
+        assert row is not None
+        assert isinstance(row.content, list)
+        mentioned_part = next(
+            p for p in row.content if p.get("type") == "mentioned-documents"
+        )
+        assert mentioned_part == {
+            "type": "mentioned-documents",
+            "documents": [
+                {
+                    "id": 77,
+                    "title": "Legacy",
+                    "document_type": "GENERAL",
+                    "kind": "doc",
+                },
             ],
         }
 

surfsense_backend/tests/unit/agents/new_chat/test_mention_resolver.py

@@ -0,0 +1,285 @@
+"""Tests for the @-mention resolver.
+
+These tests pin down the contract that ``mention_resolver`` is the
+single seam between ``MentionedDocumentInfo`` chips (frontend) and the
+canonical ``/documents/...`` virtual paths (agent). The streaming task,
+priority middleware, and persistence layer all consume the resolver's
+output — keeping the tests focused on substitute-in-text + the
+returned id partition keeps the seam stable across refactors.
+"""
+
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from app.agents.new_chat import mention_resolver
+from app.agents.new_chat.mention_resolver import (
+    ResolvedMention,
+    ResolvedMentionSet,
+    resolve_mentions,
+    substitute_in_text,
+)
+from app.agents.new_chat.path_resolver import DOCUMENTS_ROOT, PathIndex
+from app.schemas.new_chat import MentionedDocumentInfo
+
+pytestmark = pytest.mark.unit
+
+
+class TestSubstituteInText:
+    """``substitute_in_text`` is a pure string transform and is exercised
+    on every cloud-mode turn, so it has to be both fast and behaviour-
+    identical to the frontend's ``parseMentionSegments`` (longest-token
+    first, single forward pass)."""
+
+    def test_returns_text_unchanged_when_no_tokens(self):
+        assert substitute_in_text("hello @foo", []) == "hello @foo"
+
+    def test_returns_text_unchanged_when_empty(self):
+        assert substitute_in_text("", [("@x", "/documents/x.xml")]) == ""
+
+    def test_replaces_single_token_with_backtick_path(self):
+        out = substitute_in_text(
+            "see @notes please",
+            [("@notes", "/documents/notes.xml")],
+        )
+        assert out == "see `/documents/notes.xml` please"
+
+    def test_longest_token_wins_over_prefix(self):
+        # ``@Project Roadmap`` must NOT be partially matched by ``@Project``.
+        # Mirrors the FE's parseMentionSegments contract.
+        token_to_path = [
+            ("@Project Roadmap", "/documents/Roadmap.xml"),
+            ("@Project", "/documents/Project.xml"),
+        ]
+        out = substitute_in_text("about @Project Roadmap today", token_to_path)
+        assert out == "about `/documents/Roadmap.xml` today"
+
+    def test_handles_repeated_mentions(self):
+        out = substitute_in_text(
+            "@A and @A again @B",
+            [
+                ("@A", "/documents/a.xml"),
+                ("@B", "/documents/b.xml"),
+            ],
+        )
+        assert (
+            out == "`/documents/a.xml` and `/documents/a.xml` again `/documents/b.xml`"
+        )
+
+    def test_does_not_match_inside_word(self):
+        # Substitution is positional — there's no word-boundary semantics.
+        # ``@Pro`` inside ``foo@Project`` still matches; this is the same
+        # behaviour as parseMentionSegments. The test pins it so a
+        # future "fix" doesn't accidentally diverge between FE/BE.
+        out = substitute_in_text("foo@Pro", [("@Pro", "/documents/p.xml")])
+        assert out == "foo`/documents/p.xml`"
+
+    def test_idempotent_after_substitution(self):
+        # The output starts with a backtick, not ``@``, so re-running
+        # the substitution leaves it alone.
+        once = substitute_in_text("@A", [("@A", "/documents/a.xml")])
+        twice = substitute_in_text(once, [("@A", "/documents/a.xml")])
+        assert once == twice
+
+
+class TestResolveMentions:
+    """``resolve_mentions`` resolves chip ids → virtual paths and emits
+    a ``ResolvedMentionSet`` whose id partitions feed
+    ``KnowledgePriorityMiddleware``."""
+
+    @pytest.mark.asyncio
+    async def test_returns_empty_when_no_mentions(self):
+        session = MagicMock()
+        session.execute = AsyncMock()
+        result = await resolve_mentions(
+            session,
+            search_space_id=1,
+            mentioned_documents=None,
+        )
+        assert isinstance(result, ResolvedMentionSet)
+        assert result.mentions == []
+        assert result.token_to_path == []
+        assert result.mentioned_document_ids == []
+        assert result.mentioned_folder_ids == []
+        # No DB roundtrips when there's nothing to resolve.
+        session.execute.assert_not_awaited()
+
+    @pytest.mark.asyncio
+    async def test_resolves_doc_chip_to_virtual_path(self, monkeypatch):
+        chip = MentionedDocumentInfo(
+            id=42,
+            title="Notes",
+            document_type="EXTENSION",
+            kind="doc",
+        )
+        doc_row = SimpleNamespace(id=42, title="Notes", folder_id=None)
+
+        async def fake_build_index(_session, _ssid):
+            return PathIndex()
+
+        monkeypatch.setattr(mention_resolver, "build_path_index", fake_build_index)
+
+        scalars = MagicMock()
+        scalars.all.return_value = [doc_row]
+        result = MagicMock()
+        result.scalars.return_value = scalars
+        session = MagicMock()
+        session.execute = AsyncMock(return_value=result)
+
+        out = await resolve_mentions(
+            session,
+            search_space_id=5,
+            mentioned_documents=[chip],
+        )
+        assert len(out.mentions) == 1
+        mention = out.mentions[0]
+        assert mention.kind == "doc"
+        assert mention.id == 42
+        assert mention.virtual_path == f"{DOCUMENTS_ROOT}/Notes.xml"
+        assert out.mentioned_document_ids == [42]
+        assert out.mentioned_folder_ids == []
+        assert ("@Notes", f"{DOCUMENTS_ROOT}/Notes.xml") in out.token_to_path
+
+    @pytest.mark.asyncio
+    async def test_resolves_folder_chip_with_trailing_slash(self, monkeypatch):
+        chip = MentionedDocumentInfo(
+            id=9,
+            title="Reports",
+            document_type="FOLDER",
+            kind="folder",
+        )
+        folder_row = SimpleNamespace(id=9, name="Reports")
+
+        async def fake_build_index(_session, _ssid):
+            return PathIndex(folder_paths={9: f"{DOCUMENTS_ROOT}/Reports"})
+
+        monkeypatch.setattr(mention_resolver, "build_path_index", fake_build_index)
+
+        scalars = MagicMock()
+        scalars.all.return_value = [folder_row]
+        result = MagicMock()
+        result.scalars.return_value = scalars
+        session = MagicMock()
+        session.execute = AsyncMock(return_value=result)
+
+        out = await resolve_mentions(
+            session,
+            search_space_id=3,
+            mentioned_documents=[chip],
+        )
+        assert len(out.mentions) == 1
+        mention = out.mentions[0]
+        assert mention.kind == "folder"
+        assert mention.id == 9
+        assert mention.virtual_path == f"{DOCUMENTS_ROOT}/Reports/"
+        assert out.mentioned_document_ids == []
+        assert out.mentioned_folder_ids == [9]
+
+    @pytest.mark.asyncio
+    async def test_drops_chip_when_doc_is_missing(self, monkeypatch):
+        chip = MentionedDocumentInfo(
+            id=99, title="ghost", document_type="EXTENSION", kind="doc"
+        )
+
+        async def fake_build_index(_session, _ssid):
+            return PathIndex()
+
+        monkeypatch.setattr(mention_resolver, "build_path_index", fake_build_index)
+
+        scalars = MagicMock()
+        scalars.all.return_value = []
+        result = MagicMock()
+        result.scalars.return_value = scalars
+        session = MagicMock()
+        session.execute = AsyncMock(return_value=result)
+
+        out = await resolve_mentions(
+            session,
+            search_space_id=1,
+            mentioned_documents=[chip],
+        )
+        assert out.mentions == []
+        assert out.mentioned_document_ids == []
+        assert out.token_to_path == []
+
+    @pytest.mark.asyncio
+    async def test_token_to_path_is_longest_first(self, monkeypatch):
+        # Two chips whose titles are prefixes of each other — the
+        # resolver MUST sort longest-first so substitution doesn't
+        # break the ``@Project Roadmap`` vs ``@Project`` invariant.
+        chip_short = MentionedDocumentInfo(
+            id=1, title="A", document_type="EXTENSION", kind="doc"
+        )
+        chip_long = MentionedDocumentInfo(
+            id=2, title="A long one", document_type="EXTENSION", kind="doc"
+        )
+        rows = [
+            SimpleNamespace(id=1, title="A", folder_id=None),
+            SimpleNamespace(id=2, title="A long one", folder_id=None),
+        ]
+
+        async def fake_build_index(_session, _ssid):
+            return PathIndex()
+
+        monkeypatch.setattr(mention_resolver, "build_path_index", fake_build_index)
+
+        scalars = MagicMock()
+        scalars.all.return_value = rows
+        result = MagicMock()
+        result.scalars.return_value = scalars
+        session = MagicMock()
+        session.execute = AsyncMock(return_value=result)
+
+        out = await resolve_mentions(
+            session,
+            search_space_id=1,
+            mentioned_documents=[chip_short, chip_long],
+        )
+        tokens = [tok for tok, _ in out.token_to_path]
+        assert tokens == sorted(tokens, key=len, reverse=True)
+
+    @pytest.mark.asyncio
+    async def test_legacy_id_arrays_resolve_without_chip_metadata(self, monkeypatch):
+        # ``mentioned_document_ids`` (the legacy parallel array) must
+        # still resolve when no chip metadata is available — covers
+        # callers that haven't migrated to the discriminated chip list.
+        doc_row = SimpleNamespace(id=7, title="Legacy", folder_id=None)
+
+        async def fake_build_index(_session, _ssid):
+            return PathIndex()
+
+        monkeypatch.setattr(mention_resolver, "build_path_index", fake_build_index)
+
+        scalars = MagicMock()
+        scalars.all.return_value = [doc_row]
+        result = MagicMock()
+        result.scalars.return_value = scalars
+        session = MagicMock()
+        session.execute = AsyncMock(return_value=result)
+
+        out = await resolve_mentions(
+            session,
+            search_space_id=2,
+            mentioned_documents=None,
+            mentioned_document_ids=[7],
+        )
+        assert out.mentioned_document_ids == [7]
+        assert len(out.mentions) == 1
+        assert out.mentions[0].title == "Legacy"
+
+
+class TestResolvedMentionEquality:
+    """Smoke check on the dataclass behaviour we rely on for asserting
+    test outputs."""
+
+    def test_equal_when_fields_equal(self):
+        a = ResolvedMention(
+            kind="doc", id=1, title="x", virtual_path="/documents/x.xml"
+        )
+        b = ResolvedMention(
+            kind="doc", id=1, title="x", virtual_path="/documents/x.xml"
+        )
+        assert a == b

surfsense_backend/tests/unit/agents/new_chat/test_path_resolver.py

@@ -196,3 +196,50 @@ class TestVirtualPathToDoc:
         )
         assert document is target_doc
         assert session.execute.await_count == 2
+
+    @pytest.mark.asyncio
+    async def test_resolves_double_extension_for_uploaded_pdf(self):
+        # Regression: the agent renders every KB document under
+        # ``/documents/`` with a trailing ``.xml`` (via ``safe_filename``),
+        # so an uploaded PDF whose DB title is ``2025-W2.pdf`` shows up as
+        # ``/documents/2025-W2.pdf.xml`` in answers. Clicking that path
+        # must round-trip back to the row even though the title itself
+        # does NOT end in ``.xml``.
+        target_doc = SimpleNamespace(id=99, title="2025-W2.pdf", folder_id=None)
+
+        session = MagicMock()
+        session.execute = AsyncMock(
+            side_effect=[
+                _result_from_one(None),
+                _result_from_scalars([target_doc]),
+            ]
+        )
+
+        document = await virtual_path_to_doc(
+            session,
+            search_space_id=5,
+            virtual_path=f"{DOCUMENTS_ROOT}/2025-W2.pdf.xml",
+        )
+        assert document is target_doc
+
+    @pytest.mark.asyncio
+    async def test_resolves_path_without_xml_suffix(self):
+        # The user (or a hand-edited link) may pass the title-only form
+        # ``/documents/2025-W2.pdf``. The resolver must still find the row
+        # by literal title equality.
+        target_doc = SimpleNamespace(id=99, title="2025-W2.pdf", folder_id=None)
+
+        session = MagicMock()
+        session.execute = AsyncMock(
+            side_effect=[
+                _result_from_one(None),
+                _result_from_scalars([target_doc]),
+            ]
+        )
+
+        document = await virtual_path_to_doc(
+            session,
+            search_space_id=5,
+            virtual_path=f"{DOCUMENTS_ROOT}/2025-W2.pdf",
+        )
+        assert document is target_doc

surfsense_backend/tests/unit/services/streaming/test_interrupt_correlation.py

@@ -118,12 +118,8 @@ def test_get_by_tool_call_id_matches_action_request_payload() -> None:
         tasks=(
             _Task(
                 interrupts=(
-                    _Interrupt(
-                        value=_hitl("a", tool_call_id="call_xxx"), id="int_a"
-                    ),
-                    _Interrupt(
-                        value=_hitl("b", tool_call_id="call_yyy"), id="int_b"
-                    ),
+                    _Interrupt(value=_hitl("a", tool_call_id="call_xxx"), id="int_a"),
+                    _Interrupt(value=_hitl("b", tool_call_id="call_yyy"), id="int_b"),
                 )
             ),
         )
@@ -146,9 +142,7 @@ def test_first_pending_interrupt_matches_legacy_first_wins_behaviour() -> None:
 
 def test_interrupt_without_id_falls_back_to_none() -> None:
     """Snapshots from older LangGraph versions may omit ``id`` — preserve that."""
-    state = _State(
-        tasks=(_Task(interrupts=(_Interrupt(value=_hitl("a"), id=None),)),)
-    )
+    state = _State(tasks=(_Task(interrupts=(_Interrupt(value=_hitl("a"), id=None),)),))
     pending = list_pending_interrupts(state)
     assert len(pending) == 1
     assert pending[0].interrupt_id is None

surfsense_backend/tests/unit/services/streaming/test_interrupt_events.py

@@ -37,9 +37,7 @@ def test_custom_interrupt_primitive_is_converted_to_canonical_shape() -> None:
         "context": {"reason": "destructive"},
     }
     out = normalize_interrupt_payload(raw)
-    assert out["action_requests"] == [
-        {"name": "send_email", "args": {"to": "a@b"}}
-    ]
+    assert out["action_requests"] == [{"name": "send_email", "args": {"to": "a@b"}}]
     assert out["review_configs"] == [
         {
             "action_name": "send_email",

surfsense_backend/tests/unit/tasks/chat/streaming/test_stage_1_parity.py

@@ -158,9 +158,7 @@ def _classify_cases() -> list[Exception]:
     """Inputs that the FE depends on being mapped to specific error codes."""
     return [
         Exception("totally generic error"),
-        Exception(
-            '{"error":{"type":"rate_limit_error","message":"slow down"}}'
-        ),
+        Exception('{"error":{"type":"rate_limit_error","message":"slow down"}}'),
         Exception(
             'OpenrouterException - {"error":{"message":"Provider returned error",'
             '"code":429}}'
@@ -220,7 +218,7 @@ class _FakeStreamingService:
         self.calls.append(
             {"message": message, "error_code": error_code, "extra": extra}
         )
-        return f"data: {{\"type\":\"error\",\"errorText\":\"{message}\"}}\n\n"
+        return f'data: {{"type":"error","errorText":"{message}"}}\n\n'
 
 
 def test_emit_stream_terminal_error_matches_old_output_and_logs(caplog) -> None:

surfsense_backend/tests/unit/tasks/chat/streaming/test_stream_output.py

@@ -60,8 +60,14 @@ async def test_stream_output_emits_text_lifecycle_and_updates_result() -> None:
     service = _StreamingService()
     agent = _Agent(
         [
-            {"event": "on_chat_model_stream", "data": {"chunk": _Chunk(content="Hello")}},
-            {"event": "on_chat_model_stream", "data": {"chunk": _Chunk(content=" world")}},
+            {
+                "event": "on_chat_model_stream",
+                "data": {"chunk": _Chunk(content="Hello")},
+            },
+            {
+                "event": "on_chat_model_stream",
+                "data": {"chunk": _Chunk(content=" world")},
+            },
         ]
     )
     result = StreamingResult()

surfsense_backend/tests/unit/tasks/chat/streaming/test_task_span.py

@@ -37,7 +37,9 @@ def test_clear_ignored_for_non_task_tool() -> None:
 def test_clear_ignored_when_task_run_id_mismatches() -> None:
     state = AgentEventRelayState.for_invocation()
     open_task_span(state, run_id="run-open")
-    clear_task_span_if_delegating_task_ended(state, tool_name="task", run_id="run-other")
+    clear_task_span_if_delegating_task_ended(
+        state, tool_name="task", run_id="run-other"
+    )
     assert state.active_span_id is not None
     assert state.active_task_run_id == "run-open"
 

surfsense_backend/tests/unit/tasks/chat/test_content_builder.py

@@ -240,9 +240,7 @@ class TestToolHeavyTurn:
 class TestToolCallSpanMetadata:
     def test_input_available_merges_new_metadata_keys_after_start(self):
         b = AssistantContentBuilder()
-        b.on_tool_input_start(
-            "call_t", "task", "lc_t", metadata={"spanId": "spn_1"}
-        )
+        b.on_tool_input_start("call_t", "task", "lc_t", metadata={"spanId": "spn_1"})
         b.on_tool_input_available(
             "call_t",
             "task",
@@ -257,9 +255,7 @@ class TestToolCallSpanMetadata:
 
     def test_input_available_does_not_overwrite_existing_metadata_keys(self):
         b = AssistantContentBuilder()
-        b.on_tool_input_start(
-            "call_t", "task", "lc_t", metadata={"spanId": "spn_keep"}
-        )
+        b.on_tool_input_start("call_t", "task", "lc_t", metadata={"spanId": "spn_keep"})
         b.on_tool_input_available(
             "call_t", "task", {}, "lc_t", metadata={"spanId": "spn_other"}
         )