Two independent, live-reproduced causes of "Smart prompt-selection unavailable
(LLM response did not contain valid selection JSON)" in the gate:
- Cause B (openai.ts request): the response handler JSON.parsed the body with no
res.statusCode check, so a LiteLLM/vLLM HTTP 500 ("Connection error") parsed as
an empty completion and surfaced as generic "bad JSON", masking backend-down.
Now reject on status >= 400 with "OpenAI HTTP <status>: <body>" so the selector
reports the true degradedReason.
- Cause A (parseResponse + selector budget): a reasoning model (qwen3-thinking)
spends its whole 1024-token budget in reasoning_content and emits content=null,
so the {selectedNames} JSON never appears. parseResponse now falls back to
reasoning_content (incl. provider_specific_fields) when content is empty, and
the selector budget is raised 1024 -> 4000 (env MCPCTL_GATE_SELECT_MAX_TOKENS)
so thinking + the JSON answer both fit.
Note: mcpd's chat path got a reasoning_content fallback in PR #67; this is the
separate mcplocal gate-selection provider, which never did. Tests: openai-provider
(500 rejects, reasoning_content capture/preference). mcplocal suite green (749).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
