Injecting Google Calendar data as ground truth to prevent LLM schedule hallucinations

Short summary

The author solved a problem where Claude hallucinated fictional schedules by misreading date ranges in Obsidian notes. The fix: fetch 21 days of Google Calendar events via API, convert to Markdown, and inject as canonical schedule data into the daily brief prompt. The pipeline uses gcloud ADC for unattended authentication and runs via launchd.

• •Claude was misreading prose date ranges as fully booked time blocks
• •Solution injects real Google Calendar data as canonical schedule into prompts
• •Pipeline uses gcloud ADC auth and runs unattended via launchd

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