When a message dispatch fails (provider error, rate limit, empty response), Telegram now sends the user a meaningful fallback message. All other channels silently drop the failure — the user receives nothing and has no way to know something went wrong. | Channel | On dispatch error | | LINE | Sends a hardcoded "Sorry, I encountered an error..." string (no error routing) ⚠️ | Extract the error-message-selection logic into a shared helper (e.g. src/auto-reply/reply/delivery-fallback.ts) so it isn't duplicated across channel files.

TL;DR

Implement a fallback message pattern for each channel, similar to Telegram, by tracking errors and sending user-visible messages when dispatch fails.

Guidance

• Extract the error-message-selection logic into a shared helper, such as src/auto-reply/reply/delivery-fallback.ts, to avoid duplication across channel files.
• Use the onError callback and outer try/catch to track lastError for each channel.
• Check delivery state after dispatch and send a user-visible message using resolveFailoverReasonFromError when nothing is delivered and a failure occurs.
• Leverage the existing EmptyResponseError routing and resolveFailoverReasonFromError logic to classify and handle different error types, such as rate limits and timeouts.

Example

No explicit code example is provided, but the proposed fix suggests creating a shared helper function, e.g., delivery-fallback.ts, to contain the error-message-selection logic.

Notes

The implementation details may vary depending on the specific requirements and constraints of each channel. The proposed fix assumes that the resolveFailoverReasonFromError function is already handling rate-limit, auth, and timeout classification.

Recommendation

Apply the workaround by implementing the proposed fix for each channel, as it provides a more robust and user-friendly experience by sending meaningful fallback messages when dispatch fails.