Contract negotiation

Contract negotiation is the process by which a consumer and a provider reach a binding agreement on the terms of a data transfer. The full state machine and all valid transitions are defined in the IDSA Dataspace Protocol specification. RUN-DSP implements this state machine as specified.

Contract hook

At each state transition, RUN-DSP calls the configured contract service via gRPC to determine whether to proceed. This hook is the extension point for policy enforcement.

sequenceDiagram
    participant CR as Consumer RUN-DSP
    participant PR as Provider RUN-DSP
    participant CS as Contract service

    CR->>PR: DSP negotiation message (e.g. REQUESTED)
    PR->>CS: gRPC — should transition be accepted?
    CS-->>PR: Accept / Reject
    alt Accepted
        PR->>CR: DSP response (next state)
    else Rejected
        PR->>CR: DSP TERMINATED
    end

The Reference Contract Service accepts all transitions without applying any policy logic. For production use, replace it with an implementation that evaluates the actual data sharing policies of your deployment.