Capability Contract Error • AI Agent SDK

CapabilityContractError: A declared “supports_*“ capability has no backing implementation.

CapabilityContractError

Defined in the base module.

A declared `supports_*` capability has no backing implementation.

Raised once, early — when an adapter is built/registered — so a declared-but-unbacked capability can never reach a live turn as a lazy `NotImplementedError` buried in the delivery loop. The message names the offending flag and the method that must be overridden to back it.

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