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Fixed (verified)Last checked CrewAI#state#parsing

SQLiteFlowPersistence crashes when Flow state contains datetime, UUID, or set

A Flow with @persist or SQLiteFlowPersistence raises RuntimeError: State persistence failed: Object of type datetime is not JSON serializable when the Pydantic state includes datetime, UUID, or set.

From GitHub

crewAIInc/crewAI

IssuePull request

Difficulty
Easy
Time
~5 min
Steps
2
Fixed in
1.15.22
Last checked

Verified fix: PR #7376 merged on . Fixed in 1.15.22 (first published release whose tag contains the merge commit). Last checked .

Symptom

A Flow with @persist or SQLiteFlowPersistence raises RuntimeError: State persistence failed: Object of type datetime is not JSON serializable when the Pydantic state includes datetime, UUID, or set.

Evidence what you'll see

  • The report's failure line is Failed to persist state for method step_one: Object of type datetime is not JSON serializable, then FLOW CRASHED: RuntimeError: State persistence failed: Object of type datetime is not JSON serializable.
  • The crash is in lib/crewai/src/crewai/flow/persistence/sqlite.py: _to_state_dict calls state_data.model_dump() without mode="json", then _save_state_sql calls json.dumps(state_dict).

Why it happens

Pydantic v2 model_dump() keeps native Python types. json.dumps then raises TypeError: Object of type datetime is not JSON serializable. Pull request 7376 uses model_dump(mode="json") for BaseModel state, serializes dict state through to_serializable, and adds default=str on those json.dumps calls.

Affected versions

crewAI 1.15.20, crewAI Tools 1.15.20, Python 3.12, macOS Sonoma, venv. The repro uses SQLiteFlowPersistence("test_flow.db").

Fix steps

0 of 2 done

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How to check it worked

  • The report's SampleFlow with datetime, UUID, and set fields in WorkflowState completes flow.kickoff() without Object of type datetime is not JSON serializable.

If it still fails

  • Tag 1.15.21 does not contain pull request 7376. Stay on 1.15.22 or later.
  • The linked issue does not describe a remaining datetime persistence failure on 1.15.22.

Sources and credit

Summarized in our own words from these public reports. Credit goes to their authors.

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