{"record":{"id":"9567ea84d6b19c8e","repo":"odysseus-dev/odysseus","slug":"synthesis-failed-9567ea","errorCode":null,"errorMessage":"Synthesis failed","messagePattern":"Synthesis failed","errorType":"http","errorClass":"HTTPException","httpStatus":500,"severity":"error","filePath":"routes/tts_routes.py","lineNumber":43,"sourceCode":"            return tts_service.get_stats()\n        except Exception as e:\n            logger.error(f\"Failed to get TTS stats: {e}\")\n            raise HTTPException(status_code=500, detail=str(e))\n\n    @router.post(\"/synthesize\")\n    async def synthesize_speech(request: TTSRequest):\n        \"\"\"Synthesize speech from text\"\"\"\n        try:\n            if not tts_service.available:\n                raise HTTPException(\n                    status_code=503,\n                    detail={\"message\": \"TTS service not available\"}\n                )\n            \n            if request.format == \"base64\":\n                audio_b64 = tts_service.synthesize_to_base64(request.text)\n                if not audio_b64:\n                    raise HTTPException(\n                        status_code=500,\n                        detail={\"message\": \"Synthesis failed\"}\n                    )\n                return {\"audio\": audio_b64}\n            \n            else:  # audio format\n                audio_data = tts_service.synthesize(request.text)\n                if not audio_data:\n                    raise HTTPException(\n                        status_code=500,\n                        detail={\"message\": \"Synthesis failed\"}\n                    )\n                \n                # Detect format from magic bytes (MP3: ID3 tag or sync word ff e0+)\n                is_mp3 = audio_data[:3] == b'ID3' or (len(audio_data) >= 2 and audio_data[0] == 0xff and (audio_data[1] & 0xe0) == 0xe0)\n                mime = \"audio/mpeg\" if is_mp3 else \"audio/wav\"\n                return Response(\n                    content=audio_data,","sourceCodeStart":25,"sourceCodeEnd":61,"githubUrl":"https://github.com/odysseus-dev/odysseus/blob/f9235ebbf13f693a6fd29ce70b097f6ec83705bf/routes/tts_routes.py#L25-L61","documentation":"HTTP 500 from POST /api/tts/synthesize with format=='base64' when tts_service.synthesize_to_base64(text) returns an empty/falsy value. The call completed without raising but produced no audio, which the route treats as a hard failure rather than returning an empty clip.","triggerScenarios":"POST /api/tts/synthesize with {\"format\":\"base64\"} where the engine silently produces nothing: text made only of characters the engine drops (emoji/whitespace), provider returned HTTP 200 with an empty body, or a corrupt cache entry served as empty.","commonSituations":"Text containing only emoji or invisible characters; provider quota exhausted and errors swallowed; corrupted cache entry returning an empty hit.","solutions":["Retry with plain alphanumeric text to confirm the engine works at all","Check service logs for swallowed provider errors during synthesis; verify provider credentials/quota","Clear the TTS cache (POST /api/tts/clear-cache) in case a corrupt empty entry is being served","If reproducible, instrument tts_service.synthesize_to_base64 — the falsy return hides the real error"],"exampleFix":null,"handlingStrategy":"retry","validationCode":"if (!text.trim()) throw new Error('nothing to synthesize');","typeGuard":null,"tryCatchPattern":"if (resp.status === 500 && body.message === 'Synthesis failed') { backoffRetry(2); }","preventionTips":["Strip emoji/zero-width characters from text before synthesis","Fall back to plain text if rich text synthesis keeps failing","Cache successful syntheses to avoid repeated engine load"],"tags":["http","tts","synthesis","base64"],"backgroundTag":null,"analyzedSha":"f9235ebbf13f693a6fd29ce70b097f6ec83705bf","analyzedAt":"2026-08-14T21:47:48.359Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}