Session title generation silently fails with no fallback or logging #29734

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1. github-actions commented on May 28, 2026

   

   github-actionsBot

   on May 28, 2026 – with GitHub Actions

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   This issue might be a duplicate of existing issues. Please check:

   • Auto-title generation silently fails when provider has no small model #25344: Auto-title generation silently fails when provider has no small model (same silent failure behavior)
   • [BUG] Session title generation fails silently since v1.3.3 — effort parameter leaks into small model call #20269: Session title generation fails silently since v1.3.3 (same symptom: silent failure with timestamp titles)
   • Title generation fails from unavailable gpt-5-nano fallback and possible variant leakage into OpenAI small_model #26181: Title generation fails from unavailable gpt-5-nano fallback (related: failed title generation with no logging)

   Please review these issues and confirm whether your report adds new information not covered by the above.
2. github-actions

   assigned

   nexxeln

   on May 28, 2026
3. BenSharir commented on May 28, 2026

   

   BenSharir

   on May 28, 2026

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   Thanks for flagging. After reviewing:

   • Auto-title generation silently fails when provider has no small model #25344 - Same root cause (silent failure via Effect.ignore), but focuses on the ?? operator not handling Effect errors
   • [BUG] Session title generation fails silently since v1.3.3 — effort parameter leaks into small model call #20269 - Different cause (variant/effort parameter leaking into small model calls)
   • Title generation fails from unavailable gpt-5-nano fallback and possible variant leakage into OpenAI small_model #26181 - Combines both: unavailable fallback model + variant leakage

   This issue (#29734) and PR #29735 address the fallback and logging side:

   1. Add cross-provider fallback chain when primary model fails
   2. Replace Effect.ignore with warning logs so failures are visible

   This complements but doesn't fully replace #25344's fix for the ?? vs Effect.orElse semantics. The PR should help with #26181's "unavailable gpt-5-nano" scenario by trying other providers.

   Should I close this as a duplicate of #25344, or keep it open as the "solution" counterpart to that issue's "diagnosis"?
4. skwid138 commented on Jun 3, 2026

   

   skwid138

   on Jun 3, 2026

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   Reproduced on 1.15.13 — swallowed title-gen failure hid an actionable HTTP 400

   Concrete instance of swallowed title-generation failure (ensureTitle wrapped in Effect.ignore in session/prompt.ts). Version: opencode 1.15.13.

   Symptom: new sessions stayed titled "New session". I didn't see any warning at the default log level; I only found the cause with --log-level DEBUG.

   What the debug log showed:

   1. The configured small_model (openai/gpt-5-mini) returned model_not_found (unavailable for my account).
   2. The title call then routed to the session model instead of a small model — log fields small=false agent=gandalf, providerID=github-copilot modelID=claude-opus-4.7.
   3. That call sent reasoning_effort: "low", which the model rejected:

      HTTP 400 invalid_reasoning_effort:
      reasoning_effort "low" is not supported by model claude-opus-4.7; supported values: [medium]
      

   4. The 400 was swallowed by Effect.ignore, so the session silently kept its default title.

   Repro I used:

   1. In opencode.jsonc: session model github-copilot/claude-opus-4.7, small_model set to openai/gpt-5-mini (unavailable for my account — any model returning model_not_found for yours should do).
   2. Start a new session and send a first prompt (title generation fires on the first message).
   3. Title stays "New session"; the 400 appears only at DEBUG level.

   Workaround: set small_model to a model available for my account (openai/gpt-5.4-mini); the title call then routes providerID=openai modelID=gpt-5.4-mini small=true agent=title and succeeds.

   The underlying error was actionable (unavailable small model + an incompatible param on the session-model call), but the silent swallow meant it couldn't be diagnosed without reading the DEBUG log. A single WARN like "title generation failed: " would surface the cause without DEBUG-level log inspection. Related: #29737 (logging) and #27939 (configurable fallback chains via agent.title.fallbacks). See also #20269 for the effort-parameter angle.
5. BenSharir commented on Jun 11, 2026

   

   BenSharir

   on Jun 11, 2026

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   Update (2026-08-12): This issue continues to affect users. Since filing, 4 more reports have appeared: #30662, #31042, #31592, #31879 — all describing the same silent title generation failure.

   Our workaround for local setups: avoid setting agent.title.model in project configs entirely, and rely on small_model with a subscription-included model (e.g., anthropic/claude-haiku-4-5). The agent.title.model override has no fallback chain, so a single model failure silently degrades to timestamp titles.

   PR #29737 (this issue's fix) is a minimal 4-line change that replaces Effect.ignore with Effect.catchCause + warning log, making failures visible. Just rebased onto latest dev — all CI checks passed previously. Would appreciate a review when maintainers have time.

   For the fuller solution (fallback chains), see PR #27939 by @loss-and-quick.
6. BenSharir

   added a commit that references this issue on Jun 11, 2026

   fix(session): log warning when title generation fails

   ...

   This issue will close once commit d5ec277 is merged into the 'dev' branch.

   d5ec277
7. github-actions commented on Aug 11, 2026

   

   github-actionsBot

   on Aug 11, 2026 – with GitHub Actions

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   To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.
8. github-actions

   closed this as not plannedon Aug 11, 2026