System Contract

What a connected system emits and what it can do.

A system contract is the written way to define the capabilities of a connected system. This contract will be used later by D.E.S.P in order to take a decision.

Per Connected System you have a System Contract that includes:

• What State events this system will emit.
• What are the capabilities of this system.

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How Deltas are checked against the contract

When a Delta arrives, Aether checks its event against the system’s contract:

Case	What happens
The system has no contract yet	Aether creates one containing the event.
The event is not in the contract	Aether adds it to the contract. Its payload schema is inferred from this first payload.
The event is in the contract	The payload is validated against the event’s schema. A mismatch is rejected with 422 contract_violation.

An event added this way is marked PROGRESS (not final). Review it in the Aether Dashboard and edit its kind or schema if needed.

A misspelled or invented event name is not rejected: it becomes a new event in the contract. Make sure your systems only send the events you declared, e.g. by passing the contract to AI agents in their prompt.

The first payload of a new event must give each field a clear type. A field that is null, or an array that is empty or mixes types, is rejected with 422 contract_violation. Declare the event in the contract first, or send typed values.