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Build Log — January 17, 2026

Build Log — January 17, 2026

Context / Focus for Today

Focused day on improving AI coach data quality through structured_data validation. Fixed regression where structured workouts were being accepted without proper structured_data, causing inconsistent interval definitions. Added comprehensive validation and improved JSON fallback prompts.

Things I Got Done Today

Structured Data Validation

Validation Functions

  • Added structured_data validation and improved JSON fallback prompt:
    • New workoutRequiresStructuredData() function to detect interval/tempo workouts
    • New validateStructuredData() function to validate buildConfig and steps format
    • Updated validateWorkouts() to warn when structured workouts lack structured_data
    • Catches regression where structured workouts were accepted without proper data
    • Ensures consistent interval definitions across all workouts

JSON Fallback Prompt Improvements

  • Expanded JSON_FALLBACK_PROMPT with complete structured_data schema:
    • Full structured_data schema documentation
    • Complete example of VO2 max workout with proper structure
    • Running pace reference table for JSON fallback mode
    • Better guidance for AI when tool-calling fails
    • Improves reliability of workout generation in fallback scenarios

Test Coverage

Structured Data Validation Tests

  • Added comprehensive tests for structured_data validation:
    • Tests verify interval workouts without structured_data log a warning
    • Tests verify interval workouts with proper structured_data pass validation
    • Tests for malformed structured_data logging warnings
    • Tests verify simple easy runs don't require structured_data
    • Ensures validation logic works correctly across all scenarios

In Progress

  • Structured data validation (core implementation complete)
  • JSON fallback prompt improvements (documentation expanded)
  • AI coach reliability improvements (ongoing)

Targets for Tomorrow

  1. Expand test coverage — add more comprehensive tests for Garmin, AI, and component modules
  2. Monitor structured data validation — verify fix prevents regression in production
  3. Continue AI reliability improvements — improve fallback behavior

Notes / Observations

  • Fixed critical regression where structured workouts lacked proper structured_data
  • Validation functions provide clear warnings for debugging
  • JSON fallback prompt now includes complete schema and examples
  • Running pace reference table helps AI generate accurate paces in fallback mode
  • Tests ensure validation logic catches missing/malformed structured_data
  • Focused, targeted improvements to AI coach data quality
  • All changes maintain backward compatibility

Momentum Score: 7 / 10

Focused day addressing a specific regression in structured workout data handling. Added validation functions and improved JSON fallback prompts to ensure consistent workout data quality. Comprehensive tests verify the fix works correctly. While not a high-volume day in terms of features, the targeted fix prevents data quality issues that could affect user experience. Good progress on AI coach reliability.