fix: model fallback routing for all model types and default model selection
Backend: When ENABLE_CUSTOM_MODEL_FALLBACK is active and a custom model's
base model is unavailable, the fallback now swaps the model and form data
to the configured default model directly. This ensures routing uses the
fallback model's type (pipe, Ollama, or OpenAI) instead of the original
model's type, which previously caused "Model not found" errors when the
fallback was a different backend type.
Frontend: Fixed default model selection in new chat initialization where
the admin-configured default models were always overwritten by the first
available model. The first-available fallback now only triggers when the
configured defaults don't resolve to valid available models.
The signup_handler function checks has_users() before inserting a new user
and assigns the admin role based on that check. With multiple uvicorn workers,
concurrent signup requests during first-user registration can all observe an
empty user table before any insert completes, causing multiple accounts to
receive the admin role.
Fix: insert with the default role first, then check user count after the
insert. Only promote to admin if this is the only user in the database.
This eliminates the TOCTOU window between the check and the insert.
* perf: eliminate 2 redundant full chat deserialization on every message send (#162)
Problem:
Every message send triggered get_chat_by_id_and_user_id which loads the
entire Chat row — including the potentially massive JSON blob containing
the full conversation history — even when the caller only needed a
simple yes/no ownership check or a single column value.
Two call sites in the message-send hot path were doing this:
1. main.py ownership verification: loaded the entire chat object including
all message history JSON, then checked `if chat is None`. The JSON blob
was immediately discarded — only the existence of the row mattered.
2. middleware.py folder check: loaded the entire chat object including all
message history JSON, then read only `chat.folder_id` — a plain column
on the chat table that requires zero JSON parsing.
Fix:
- Added `chat_exists_by_id_and_user_id()`: uses SQL EXISTS subquery which
returns a boolean without loading any row data. The database can satisfy
this from the primary key index alone.
- Added `get_chat_folder_id()`: queries only the `folder_id` column via
`db.query(Chat.folder_id)`, which tells SQLAlchemy to SELECT only that
single column instead of the entire row.
Both new methods preserve the same error handling semantics (return
False/None on exception) and user_id filtering (ownership check) as
the original get_chat_by_id_and_user_id.
Impact:
- Best case (typical): eliminates deserializing 2 full chat JSON blobs per
message send. For long conversations (hundreds of messages with tool
calls, images, file attachments), this blob can be multiple megabytes.
- Worst case: no regression — the new queries are strictly cheaper than
the old ones (less data transferred, less Python object construction,
no Pydantic model_validate overhead).
- The 3 remaining full chat loads in process_chat_payload (load_messages_from_db,
add_file_context, chat_image_generation_handler) are left untouched as
they genuinely need the full history and require separate analysis.
* Address maintainer feedback: rename method and inline call (#166)
- Rename chat_exists_by_id_and_user_id -> is_chat_owner
- Remove intermediate chat_owned variable; call is_chat_owner directly in if condition
feat: add citation sources for fetch_url tool results
URL fetches now produce clickable citation sources in the UI, matching
the existing behavior of search_web and knowledge file tools. When a
model calls fetch_url during native tool calling, the fetched URL
appears as a citable source with a content preview, giving users full
transparency into what pages the model referenced.
Previously loaded the entire ChatModel (including the full conversation JSON
blob) just to extract the title string. Now queries only the Chat.title
column directly, which is already a top-level DB column.
The GET /chats/shared endpoint was loading full Chat rows including
the entire conversation history JSON blob, only to discard it and
return SharedChatResponse (id, title, share_id, timestamps). Now
uses with_entities() to select only the 5 needed columns, avoiding
deserialization of potentially large chat JSON for every shared chat.
RFC 7644 §3.4.2.4 specifies that out-of-range pagination values MUST be
clamped, not rejected. The previous implementation used FastAPI Query
constraints (ge=1, le=100) which caused a 422 response for values like
startIndex=0 or count=9999 — violating the spec.
For both /Users and /Groups:
- startIndex < 1 is now treated as 1 (spec: "SHALL be interpreted as 1")
- count < 0 is now treated as 0 (spec: "SHALL be interpreted as 0")
- count > 100 is clamped to the server maximum of 100
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
When models reference functions (via filterIds/actionIds) that no longer
exist in the database, the /api/models endpoint crashes with a 500 error,
preventing the UI from loading chats entirely. This can happen after
upgrades when built-in functions are removed or when user-created
functions are deleted while still referenced by models.
Instead of raising an exception, log at INFO level and skip the missing
function so the rest of the models load successfully.
Fixes#21464https://claude.ai/code/session_015JRM7m2bNeZPBBmV2Gv4Mj
Co-authored-by: Claude <noreply@anthropic.com>
Classic298