MCP preview after the server lost a session (it expired, or the MCP
process restarted):
- Every server state has an id, made when the state is created. The tab
notices a new id even when the version numbers happen to match, and
every push names the state it was based on, so one based on a lost state
is refused, also when it comes before the tab's first poll (the server
recovers the saved file first).
- The tab keeps the newest canvas XML, saved or not. When the server knows
nothing (no file) or exactly what the tab last saved, the canvas wins and
is saved, so edits made while the server was down are kept. Otherwise
the server's diagram (an AI write the tab missed, a cleared document
that was saved) is shown and the tab's copy goes to History.
- Late answers to an old state's push or poll are dropped; a failed push
says the server is unreachable; Download as .drawio saves the canvas.
Settings and server:
- Saved providers this version does not know stay in storage with their
keys, and sending no longer trips over them.
- The desktop "Ollama (Local)" preset with a key goes to local Ollama
again; a server model's Ollama URL variable is read; the admin panel
writes Ollama Cloud's URL for a key without one.
- Provider error texts show again in the desktop app and for EdgeOne.
- .env: a quoted value followed by a comment ending in a quote is read as
dotenv reads it; unquoted values are unchanged.
- Desktop app: the next launch opens the port where a chat was last
saved; a launch elsewhere that saves nothing does not move it, and a
page with no chats lets the next launch try the other port once.
- The Test button no longer stays busy after another tab changed the key.
- A completed append_diagram is no longer undone by an earlier failed
edit's preview; a file read once in vain is saved again once it is read
or gone.
From the first batch's review:
- The admin panel's Test of an entry without a URL now tests the server's
<P>_BASE_URL, where chat sends the entry's key; chat is unchanged (the
first fix rerouted working setups).
- The model list ends downloads that are too large, accepts answers
without a body, and keeps the "redirects are not allowed" explanation.
- A test covers the preview's History rendering.
- Bedrock: a request's AWS region must be a region name. It becomes part
of the endpoint's host name, so a value such as
"us-east-1.attacker.example/" sent the server's bearer token or signed
request to another host.
- MCP preview server: only the preview page itself (Origin equal to the
Host) or a non-browser client may call it; a page on another localhost
port could replace the diagram with a plain text POST. History builds
its thumbnails element by element and shows only SVG data images, so a
stored value can no longer run script in the preview.
- chat, validate-model, validate-diagram, provider-models and parse-url
take JSON bodies only, so another website cannot make the user's own
server (the desktop app, a local install) run models with their keys;
the desktop app also refuses a foreign Host (DNS rebinding).
- The model list reads at most 2 MB, also through the Gateway SDK, and
answers only with its own error texts: the URL is the caller's and may
be an internal address.
- An admin panel provider with its own key and no URL no longer inherits
the global <P>_BASE_URL, which may be a proxy for another key; OpenAI
then gets the official endpoint, as its Test. Azure keeps the server's
resource.
Found by the second PR review:
- With AWS_BEARER_TOKEN_BEDROCK set on the server, a request with the
user's AWS keys ran on the server's token: the Bedrock SDK prefers it.
Checked with Bedrock: invalid user keys used to get an answer.
- An OpenAI key with the official URL filled in (the settings form does
that) went to the Responses API. Back to main's rule: a configured base
URL uses Chat Completions.
- A user's Ollama key went to the server's OLLAMA_BASE_URL, for chat and
for the model list. Like every other provider, it goes to the user's
base URL or Ollama Cloud.
- The server's keyless Ollama and EdgeOne were not counted in the quota.
- AI_MODEL models on the server's keys ran on any provider with a server
key, not only on AI_PROVIDER.
- A user's Azure key without a base URL used the server's resource name.
- The admin panel's Test button failed whenever access codes were set.
- DeepSeek's errors in the stream (plain text) were shown as they were,
without a hint and also on the server's keys. Bedrock's throttling in
the stream was not recognised as a rate limit.
- The EdgeOne function accepted text/plain; x=application/json, which
other sites can send without a CORS preflight.
- Desktop app: a launch that found the old port taken for a moment (the
previous version still quitting after an update) remembered the new
port for good. The new port is kept only when Windows reserves the old
one. A failed read of the presets file moved it aside as corrupt, and a
save could then replace the presets. Switching presets on the same port
now reloads the page. The dev launcher no longer misses a preset change
made before or during a restart.
Found by the PR review, each with a test that failed first:
- Quota: any key header skipped it, even one the provider never reads
(x-aws-access-key-id with OpenAI), so a request ran on the server's
key without being counted. The check now runs after the model is
resolved and uses usesServerCredentials. On main already.
- usesServerCredentials read the raw base URL; "/" cleans up to none, so
an Ollama request ran on the server's key past the server-model check.
- SGLang's default 127.0.0.1:8000 only fills the settings form. Chat and
the model list used it as a real address, so the server called its own
machine even with private URLs blocked. Now a base URL is required.
- With a user's OpenAI key and no base URL, the SDK read the server's
OPENAI_BASE_URL. The official endpoint is now passed. On main already.
- The Test button refused nothing on the server's keys (Ollama Cloud),
and a 15 s timeout reported "connected, no tool call".
- The model list for Ollama without a base URL came from ollama.com while
chat went to the server's Ollama.
- Bedrock's "Too many tokens, please wait" counted as context too long.
- On the server's keys the provider's error text stays in the server log;
it can name the server's AWS account, role or internal hosts.
- Desktop app: the preset keys are the user's own (NEXT_AI_DRAWIO_DESKTOP),
so Max Output Tokens can be raised and keyless models in settings work
again. A launch that found the remembered port taken no longer replaces
it, which hid the user's chats and settings for good.
The "Fetch models" button asks the provider for its models (OpenAI-style
/models, Anthropic, Google, Ollama, OpenRouter, Vercel Gateway, AIHubMix)
and shows them in a searchable picker. This replaces the route that only
worked for AIHubMix.
A snapshot of models.dev (MIT) says which models support tool calls.
Models without them get a "no tool calls" badge in the picker and a hint
in the model list, since drawing needs tool calls. Refresh the snapshot
with scripts/update-model-catalog.mjs.
dayuan.jiang