github/copilot-sdk · error · ValueError

Missing required fields in ModelPolicy: state=

Error message

Missing required fields in ModelPolicy: state={state}, terms={terms}

What it means

ModelPolicy.from_dict requires both 'state' and 'terms' keys in a model's policy object and raises ValueError when either is missing/None. The library models per-model policy (enablement state plus terms) as mandatory so downstream code can rely on both values.

Solutions

Update the server/client versions so model policy payloads include both 'state' and 'terms'
Filter or skip models whose policy payload is incomplete before decoding
Fix fixtures/mocks to include a complete policy: {'state': ..., 'terms': ...}

Example fix

// before (mock)
{"policy": {"state": "enabled"}}
// after
{"policy": {"state": "enabled", "terms": "https://example.com/terms"}}

Defensive patterns

Strategy: validation

Validate before calling

def is_complete_model_policy(p: dict | None) -> bool:
    return isinstance(p, dict) and p.get("state") is not None and p.get("terms") is not None

Type guard

def has_model_policy(model: dict) -> bool:
    p = model.get("policy")
    return isinstance(p, dict) and "state" in p and "terms" in p

Try / catch

try:
    policy = ModelPolicy.from_dict(model["policy"])
except ValueError as e:
    if str(e).startswith("Missing required fields in ModelPolicy"):
        policy = None  # treat model as policy-less
    else:
        raise

Prevention

Validate model-catalog entries before batch decoding
Skip models with incomplete policy objects rather than failing the whole list
Pin client/server versions so the model-policy schema matches

When it happens

Trigger: The models/list response contains a model whose 'policy' object lacks 'state' or 'terms'; a server or mock emits policy as {} or with only one key.

Common situations: Newer/older server builds with a changed model-policy schema; models listed in preview states that omit terms; cached or mocked model catalogs in tests.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of github/copilot-sdk@cd8cf15dc3 (2026-09-09). Data as JSON: /api/errors/71ae25b59ae994ee. Report an issue: GitHub.

Appendix: source

Thrown at python/copilot/client.py:1084

        result["supports"] = self.supports.to_dict()
        result["limits"] = self.limits.to_dict()
        return result


@dataclass
class ModelPolicy:
    """Model policy state"""

    state: str  # "enabled", "disabled", or "unconfigured"
    terms: str

    @staticmethod
    def from_dict(obj: Any) -> ModelPolicy:
        assert isinstance(obj, dict)
        state = obj.get("state")
        terms = obj.get("terms")
        if state is None or terms is None:
            raise ValueError(
                f"Missing required fields in ModelPolicy: state={state}, terms={terms}"
            )
        return ModelPolicy(state=str(state), terms=str(terms))

    def to_dict(self) -> dict:
        result: dict = {}
        result["state"] = self.state
        result["terms"] = self.terms
        return result


@dataclass
class ModelBilling:
    """Model billing information"""

    multiplier: float | None = None
    token_prices: ModelBillingTokenPrices | None = None

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