5 posts tagged with "FastAPI"

Debugging a silent failure where a document sync task marked everything failed in a RAG knowledge base project — full writeup below.

TL;DR​

A shared method was refactored with a new parameter signature, but one caller was missed. The caller passed arguments under the old contract and threw TypeError — except the call sat inside a try/except that quietly funneled the exception into a failed counter. No crash, no ERROR in the logs, just a number ticking up. These "silent failures" are the hardest bugs to track down. Two fixes: grep all callers after a signature refactor; and make except blocks log or re-raise, never swallow silently.

Encountered this issue while building an AI Agent platform for a client: needed to support multiple search providers (Tavily, Serper, Brave, Bing) while ensuring tool call failures don't interrupt the Agent's conversation flow.

TL;DR​

1. Define SearchProvider abstract base class + SearchResult data model for unified interface and output
2. Each provider inherits the base class, implements search() method with field mapping
3. Key design: Return SearchResult with error info on failure, never raise exceptions

在为客户构建 AI 客服自动化系统时遇到此问题，记录根因与解法。

TL;DR​

FastAPI 的 StreamingResponse 在客户端断开连接时会取消生成器任务，导致 asyncio.CancelledError。正确做法是在生成器中捕获该异常并 re-raise，否则会导致异常日志污染和资源泄漏。

TL;DR​

Pydantic v2 no longer supports class Config. Use model_config = ConfigDict(from_attributes=True) instead. If your model has a field named model_config, you must rename it to avoid conflict with the reserved attribute.

在为客户构建 SaaS 认证系统时遇到此问题，记录根因与解法。

TL;DR​

Supabase Auth + FastAPI 集成有三个常见坑：JWKS 路径不是标准路径、ES256 签名需转换为 DER 格式、用户首次登录时本地数据库无记录。本文提供完整解决方案。