FastAPI 0.140.0 reduces dependency memory usage significantly
Less RAM with the same code – FastAPI's latest release optimizes dependency resolution.
FastAPI 0.140.0, released on July 24, 2024, is a maintenance and performance-focused update from creator Sebastián Ramírez (tiangolo). The standout change is a refactor that reduces memory usage in dependencies (PR #16049). While the release notes don't quantify the improvement, this optimization targets FastAPI's dependency injection system, which can become memory-intensive in large applications with many nested dependencies. For developers running complex APIs with multiple interrelated dependencies, this update may free up significant RAM without any code changes.
The release also includes numerous documentation improvements: links were fixed (PR #15967), a new Library Skills documentation page was added (PR #16041), and the FastAPI People and related pages were restructured (PR #16015). Documentation now defaults to using uv projects instead of previous setup methods (PR #16032). On the internal side, a CI memory benchmark was introduced (PR #16046) to catch regressions, and obsolete scripts for generating FastAPI People data were removed (PR #16016). The release is signed with a verified GPG key and has received 7 rocket reactions from the community.
- Memory usage in dependencies reduced via PR #16049 by tiangolo – no code changes needed
- Documentation restructured: new Library Skills page, uv projects set as default, fixed links
- CI now includes a memory benchmark (PR #16046) to prevent future regressions
Why It Matters
Less memory overhead in dependency injection means faster, more scalable FastAPI apps for production loads.