| type |
status |
superseded_by |
date |
agent_author |
tags |
related_files |
| decision |
superseded |
011-opt-in-vendor-fallback |
2026-03-17 |
claude |
| data |
| alpha-vantage |
| yfinance |
| fallback |
|
| tradingagents/dataflows/interface.py |
| tradingagents/dataflows/alpha_vantage_scanner.py |
| tradingagents/dataflows/yfinance_scanner.py |
|
Context
Alpha Vantage free/demo key doesn't support ETF symbols and has strict rate limits. Need reliable data for scanner.
The Decision
route_to_vendor() catches AlphaVantageError (base class) plus ConnectionError and TimeoutError to trigger fallback.- AV scanner functions raise
AlphaVantageError when ALL queries fail (not silently embedding errors in output strings).
- yfinance is the fallback vendor and uses SPDR ETF proxies for sector performance instead of broken
Sector.overview.
Constraints
- Functions inside
route_to_vendor must RAISE on failure, not embed errors in return values.
- Fallback catch must include
(AlphaVantageError, ConnectionError, TimeoutError), not just RateLimitError.
Actionable Rules
- Any new data vendor function used with
route_to_vendor must raise on total failure.
- Test both the primary and fallback paths when adding new vendor functions.