| license: mit | |
| tags: | |
| - fastapi | |
| - python-3.13 | |
| - bcrypt | |
| - passlib | |
| - jwt-authentication | |
| # 🛡️ Fixing `ValueError: password cannot be longer than 72 bytes` in Python 3.12 / 3.13 (`passlib` + `bcrypt`) | |
| [](https://yahiaoui26.gumroad.com/l/fastapi-gemini-blueprint) | |
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| When deploying **FastAPI** authentication routes using `passlib[bcrypt]` on **Python 3.12 or Python 3.13**, newer versions of `bcrypt` (`>= 4.1.0`) raise: | |
| ```text | |
| ValueError: password cannot be longer than 72 bytes, truncate manually if necessary | |
| ``` | |
| during `passlib`'s internal `detect_wrap_bug` startup check. | |
| ## ✅ The Instant Production Fix | |
| Pin `bcrypt==4.0.1` alongside `passlib[bcrypt]` in your `requirements.txt`: | |
| ```txt | |
| fastapi | |
| uvicorn | |
| passlib[bcrypt] | |
| bcrypt==4.0.1 | |
| python-jose[cryptography] | |
| pydantic[email] | |
| ``` | |
| --- | |
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