Fix JSON schema flow state kickoff inputs

[vinibrsl]

Allow required JSON schema state fields to be supplied by kickoff inputs instead of requiring every field to exist in state.default before runtime.

Example: a flow with required lead_name and no state.default can now run with kickoff inputs={"lead_name": "Ada Lovelace"}.

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Note

Low Risk
Small, targeted change to initial state construction; non-missing validation still fails fast, and kickoff continues to validate merged state.

Overview
JSON-schema flows no longer fail at startup when required fields are absent from state.default. _build_definition_state_model still tries normal construction from defaults; if Pydantic reports only missing field errors, it falls back to model_construct so kickoff can supply those values via _initialize_state. Any other validation errors are unchanged and still raise.

A regression test covers a declarative flow with a required lead_name and no default, kicked off with inputs={"lead_name": "Ada Lovelace"}.

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Summary by CodeRabbit

• Bug Fixes
  • Improved handling of required input fields when starting a flow, so missing-field validation no longer blocks runs that provide those values at launch.
  • Flows using structured state now preserve supplied input data more reliably, including required fields and generated identifiers.
• Tests
  • Added coverage for flows with required structured state fields provided through kickoff inputs.

[corridor-security]

Summary: This PR changes JSON schema flow state construction to permit missing required state fields at initialization when they are expected to be provided later via kickoff inputs; no exploitable security vulnerabilities were identified.

Risk: Low risk. The change affects internal state validation behavior and does not introduce a new public endpoint, authentication/authorization boundary, external integration, or direct handling of sensitive data.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 83f952bd-17eb-4547-b2a0-61b1f435b223

📥 Commits

Reviewing files that changed from the base of the PR and between 5827abb and d3c2fff.

📒 Files selected for processing (2)

• lib/crewai/src/crewai/flow/runtime/__init__.py
• lib/crewai/tests/test_flow_from_definition.py

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📝 Walkthrough

Walkthrough

Flow state construction now falls back to unvalidated model construction when validation fails only because required fields are missing. Tests add a json_schema flow fixture and verify required state values can be supplied through kickoff(inputs=...).

Changes

JSON schema state fallback

Layer / File(s)	Summary
State construction fallback lib/crewai/src/crewai/flow/runtime/__init__.py	_build_definition_state_model catches missing-field ValidationErrors and uses model_construct(**kwargs) in that case; other validation errors are re-raised.
Required-input fixture and kickoff test lib/crewai/tests/test_flow_from_definition.py	A new fixture defines a required lead_name field in json_schema state, and a test checks kickoff(inputs=...) populates the field, returns it from begin, and includes an id in the resulting state.

Suggested reviewers

• joaomdmoura

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: allowing required JSON schema flow state fields to be provided via kickoff inputs.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-flow-definition-defaults

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