Summary

When current_provider is the bare "custom" string (e.g. pointing to a local Ollama/llama-swap instance), the /model picker fails to highlight the active custom endpoint as current.

Root Cause

In list_authenticated_providers() section 4 (custom providers), the slug is resolved to "custom:<name>" form (e.g. "custom:ollama"), but the is_current check only does slug == current_provider. When current_provider = "custom" and the slug is "custom:ollama", the comparison fails.

Additionally, the CLI and TUI callers of list_authenticated_providers() did not pass current_base_url, so the existing URL-matching logic in section 4 (which could have set the slug to current_provider) was never triggered.

Fix

1. hermes_cli/model_switch.py — Add URL-based fallback for is_current: when slug != current_provider, also check if the custom endpoint's base_url matches current_base_url (case-insensitive, trailing-slash-normalized).

2. cli.py — Pass current_base_url=self.base_url or "" to list_authenticated_providers() so the URL fallback works in the CLI picker.

3. tui_gateway/server.py — Pass current_base_url=getattr(agent, "base_url", "") or "" to list_authenticated_providers() so the URL fallback works in the TUI picker.

Regression Coverage

Three new tests in tests/hermes_cli/test_model_switch_custom_providers.py:

• test_is_current_matches_bare_custom_via_base_url — verifies the URL fallback highlights the correct endpoint when current_provider="custom" and current_base_url matches
• test_is_current_bare_custom_without_base_url_not_false_positive — verifies no false positive when current_base_url is empty
• test_is_current_url_match_is_case_insensitive — verifies case-insensitive URL comparison

Testing

43 passed in 12.86s (hermetic, scripts/run_tests.sh)

Fixes Fix: is_current check fails for bare 'custom' provider in custom endpoints section #20811