## Summary
Follow-up to #751/#752. Code review identified a case where `_normalize_session_model_in_place` could call `session.save()` (which triggers a full session index rebuild) for sessions with `model: null` or missing model field.
Root cause: `_resolve_compatible_session_model(None)` returns `(default_model, True)` when a default exists — which was interpreted as "changed, needs save." But there's nothing to correct for a session with no model; the default is just a fallback for display purposes, not a cross-provider correction worth persisting.
Fix: capture `original_model` before calling `_resolve_compatible_session_model`. Only call `session.save()` if `original_model` was non-empty and actually changed.
Adds a test asserting `save_calls == []` when `session.model is None`.
No behavior change for sessions with a real model (the primary use case of #751 is unaffected).
## Summary
Regression fix for #751.
Models with custom or unrecognized prefixes (e.g. `custom-provider/my-model`, `test/import-model`) were being incorrectly replaced with the active provider default. Root cause: `_normalize_provider_id("custom-provider")` matched the `"custom"` prefix and returned `"custom"`, which ≠ `active_provider` → normalization fired.
Two-part fix:
1. Add `"custom"` and `"openrouter"` to the `model_provider` exclusion set in `_resolve_compatible_session_model` (parallel to the existing `active_provider` guard)
2. Return `""` for unknown prefixes in `_normalize_provider_id` so the `if model_provider` truthiness check safely short-circuits
Adds a regression test covering `custom-provider/`, `test/`, `my-local-llm/`, and `lmstudio-community/` prefixes.
## Tests
1499 passed, 0 failures (was 2 failures before this fix)
## Summary
Rebased-on-behalf of @likawa3b (originally PR #748 — stale base).
Sessions can outlive provider changes. When an old session still points to a model from a previous provider (e.g. `gemini-3.1-pro-preview` after switching the agent to OpenAI Codex), starting a chat hits the wrong backend and fails silently.
This PR adds a lightweight normalization pass:
- `_normalize_provider_id()` maps common prefixes to canonical provider IDs
- `_resolve_compatible_session_model()` checks the session model's provider against `active_provider` and returns the default model if they differ
- `_normalize_session_model_in_place()` is called at GET `/api/session` — corrects and persists stale models once
- Chat start also normalizes via `_resolve_compatible_session_model()` and returns `effective_model` in the response
- `messages.js` applies `effective_model` back to the UI/localStorage/dropdown if set
Closes#748
## Tests
1498 passed (2 pre-existing ordering failures unrelated to this PR; 5 new tests added in `test_provider_mismatch.py`).
**Original author:** @likawa3b
When a user switches the model via the model picker while a session has
existing messages, a toast now informs them: 'Model change takes effect
in your next conversation'. This prevents confusion when the model
dropdown updates visually but the running conversation continues with
the original model.
Implementation: 4-line addition in modelSelect.onchange in boot.js,
after the existing provider-mismatch warning. Checks S.messages.length
(the reliable in-memory array) and guards showToast with typeof.
Synthesized from PRs #516 (armorbreak001), #517 and #518 (cloudyun888).
Placement follows #518's correct boot.js approach. Reference corrected
from S.session.messages to S.messages (always initialized by loadSession).
4 new tests in test_provider_mismatch.py::TestModelSwitchToast.
Co-authored-by: armorbreak001 <armorbreak001@users.noreply.github.com>
Co-authored-by: cloudyun888 <cloudyun888@users.noreply.github.com>
* fix: warn on provider/model mismatch, surface auth errors (#266)
Fixes#266 — WebUI silently ignores provider/model selection mismatch.
The problem: selecting an OpenRouter (or Anthropic/OpenAI) model while
Hermes is configured for a different provider (e.g. local Ollama) sends
the request to the wrong endpoint, which returns a 401 Unauthorized error
with no UI indication of why.
Three-layer fix:
1. api/streaming.py — detect 401/auth errors explicitly
Added is_auth_error detection covering '401', 'AuthenticationError',
'authentication', 'unauthorized', 'invalid api key', and the specific
Ollama error string 'no cookie auth credentials'. Auth errors emit
apperror with type='auth_mismatch' and a hint pointing to 'hermes model'.
2. static/ui.js — expose active_provider and warn on selection
- populateModelDropdown() stores data.active_provider from /api/models
as window._activeProvider (the field was already in the response but
the frontend never used it)
- New _checkProviderMismatch(modelId) helper: compares the selected
model's slash-prefix (e.g. 'openai/' from 'openai/gpt-4o') against
the active provider. Skips the check for 'openrouter' and 'custom'
to avoid false positives on configs that legitimately route any model.
3. static/boot.js — warn on model dropdown change
modelSelect.onchange calls _checkProviderMismatch() and shows a toast
when the selected model looks incompatible with the configured provider.
4. static/messages.js — distinct UI label for auth errors
apperror handler now distinguishes type='auth_mismatch' and shows
'Provider mismatch' as the error label instead of 'Error'.
5. static/i18n.js — provider_mismatch_warning and provider_mismatch_label
keys added to all 5 locales (en, es, de, zh-Hans, zh-Hant).
Tests: 21 new tests in tests/test_provider_mismatch.py covering all
five change areas. 679/679 total pass (658 baseline + 21 new).
* fix: t() call args spread + use i18n label for auth mismatch
1. ui.js: _checkProviderMismatch passed [modelId, ap] as a single
array arg to t(). Since t(key, ...args) spreads, the function
received the array as m and undefined as p. Fixed to pass as
separate args: t('provider_mismatch_warning', modelId, ap).
2. messages.js: 'Provider mismatch' label was hardcoded instead of
using t('provider_mismatch_label'). Now uses the i18n key with
fallback for when t() isn't available.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
