Sample
fastapi 0.141.1: Exclude default values in Pydantic models nested in dict keys and values when serializing with jsonable_encoder as fixed in FastAPI 0.140.9
Verified sample for pypi fastapi 0.141.1: Exclude default values in Pydantic models nested in dict keys and values when serializing with jsonable_encoder as…
sha256:b09b062b12f13c860852641882840dceca140b65e173f95222f347f4f95b25b6
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MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
python linux x64 python python pip
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| python 3.12 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1 |
2026-08-16 |
| python 3.12 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1 |
2026-08-18 |
Case
HOW- Goal
- Exclude default values in Pydantic models nested in dict keys and values when serializing with jsonable_encoder as fixed in FastAPI 0.140.9
- Symbols
-
- fastapi.encoders.jsonable_encoder
- fastapi.FastAPI
- fastapi.testclient.TestClient
- Environment
- python
- Created
- 2026-08-16T06:22:41Z
Contract
- assert TestClient targets http://testserver, so the contract runs with network off and no DNS sockets
- assert jsonable_encoder([item], exclude_defaults=True) excludes default fields from items in top-level lists
- assert jsonable_encoder({'item': item}, exclude_defaults=True) propagates exclude_defaults into dict values instead of leaking default fields
- assert jsonable_encoder({'items': [item]}, exclude_defaults=True) propagates exclude_defaults through dicts containing lists
- assert jsonable_encoder({'data': {'items': [item]}}, exclude_defaults=True) propagates exclude_defaults through deeply nested dicts
- assert jsonable_encoder preserves default fields when exclude_defaults is False or omitted
- assert jsonable_encoder preserves non-default overridden fields when exclude_defaults is True
- assert exclude_defaults=True strips fields explicitly assigned their default value whereas exclude_unset=True retains them
- assert jsonable_encoder excludes defaults from nested Pydantic container models inside dictionaries
- assert jsonable_encoder({'data': null_model}, exclude_none=True) excludes None fields consistently
- assert FastAPI route responses returning dicts with exclude_defaults=True omit default fields over the wire
Files
- NOTES.md
- csx.json
- requirements.txt
- src/__init__.py
- src/app.py
- test/contract.py