Why do ContractOffers require a "1:" at the start of their ID?

[mark-olchanski]

As the title says, I can only bring the Contract Negotiation process to work when the Contract Offer-ID starts with a "1:". What is the intention behind this?

[DominikPinsel]

The ID of the contract offer consists of a contract definition id and a unique offer part, that are sparated by a semicolon. E.g. [contractDefinitionId]:[uuid].
The reason you are finding a '1' there is, that the sample ContractDefinition, that was used to generate the offer, has probably the id '1'.

_{Dominik Pinsel dominik.pinsel@daimler.com, Daimler TSS GmbH, legal info/Impressum}

[ndr-brt]

Yes. I was wondering what was the reason for this choice, in my opinion would be better to separate those id in two different fields, giving to the agreement its own id.

[DominikPinsel]

The ContractDefinition id is there is to find the corresponding ContractDefinition in case of a future negotation for a ContractOffer(which are not persisted as long as no negotiation exist). The second part is there to have a unique ID, as it would be possible to generate thousands of ContractOffers from a single ContractDefinition.
But you are probably right that there might be a better solution. Putting the ContractDefinition in the offer-id feels like a workaround.

_{Dominik Pinsel dominik.pinsel@daimler.com, Daimler TSS GmbH, legal info/Impressum}

[mark-olchanski]

Thank you for your explanation. But how come that I can't perform a successful contract negotiation with any other ContractDefinition? Doing something along the line of id("${contractDefinition.id}:${UUID.randomUUID()}") still resultes in a rejection.

[DominikPinsel]

At the moment all ContractOffers that do not match excatly an already existing ContractOffer are rejected. Therefore, initiating a custom negotiation, that does not contain something that is already offered, is not possible.

[jimmarino]

As the title says, I can only bring the Contract Negotiation process to work when the Contract Offer-ID starts with a "1:". What is the intention behind this?

Contract offers by design must originate from the provider, particularly given that allowing consumer-generated contract offers for data originating at a provider is a security risk. The contract offer id is opaque from the standpoint of the client. The fact that it is a concatenated id is an implementation detail of the EDC and not relevant to the client.

For contract negotiation to work, the client must pass back an id that was provided in a previous request.