This specification defines a RESTful API over HTTPS for the Contract Negotiation Protocol.
The OpenAPI definitions for this specification can be accessed here.
-
The
<base>
notation indicates the base URL for a connector endpoint. For example, if the base connector URL isconnector.example.com
, the URLhttps://<base>/negotiation/request
will map tohttps//connector.example.com/negotiation/request
. -
All request and response messages must use the
application/json
media type.
In the event of a client request error, the connector must return an appropriate HTTP 4xxx client error code. If an error body is returned it must be a ContractNegotiationError with the following properties:
Field | Type | Description |
---|---|---|
processId | UUID | The contract negotiation unique id. |
code | string | An optional implementation-specific error code. |
reasons | Array[object] | An optional array of implementation-specific error objects. |
If a client or provider connector makes a request that results in an invalid contract negotiation state transition as defined by the Contract Negotiation Protocol, it must return
an HTTP code 400 (Bad Request) with an ContractNegotiationError
in the response body.
All requests should use the Authorizartion
header to include authorization data as specified by an authorization protocol such as OAuth2
. The Authorization
HTTP header is optional if the connector does not require authorization. This specification does not mandate the use of a particular authorization standard.
GET https://connector.provider.com/negotiations/:id
Authorization: ...
If the negotiation is found and the client is authorized, the provider connector must return an HTTP 200 (OK) response and a body containing the ContractNegotiation:
{
"@context": "https://w3id.org/dspace/v0.8/context.json",
"@type": "dspace:ContractNegotiation"
"@id": "urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3",
"dspace:state" :"REQUESTED"
}
Predefined states are: REQUESTED
, OFFERED
, ACCEPTED
, AGREED
, VERIFIED
, FINALIZED
, and TERMINATED
.
If the negotiation does not exist or the client is not authorized, the provider connector must return an HTTP 404 (Not Found) response.
A contract negotiation is started and placed in the REQUESTED
state when a consumer POSTs
a ContractRequestMessageto negotiations/request
:
POST https://connector.provider.com/negotiations/request
Authorization: ...
{
"@context": "https://w3id.org/dspace/v0.8/context.json",
"@type": "dspace:ContractRequest"
"@id": "urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3",
"dspace:dataSet": "urn:uuid:3dd1add8-4d2d-569e-d634-8394a8836a88",
"dspace:offerId": "urn:uuid:2828282:3dd1add8-4d2d-569e-d634-8394a8836a88",
"dspace:callbackAddress": "https://......"
}
The callbackAddress
property specifies the base endpoint URL
where the client receives messages associated with the contract negotiation. Support for the HTTPS
scheme is
required. Implementations may optionally support other URL schemes.
Callback messages will be sent to paths under the base URL as described by this specification. Note that provider connectors should properly handle the cases where a trailing /
is included with or absent from the callbackAddress
when resolving full URL.
The @id is the correlation id that will be used for callback messages.
The provider connector must return an HTTP 201 (Created) response with the location header set to the location of the contract negotiation and a body containing the ContractNegotiation message:
Location: /negotiations/urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3
{
"@context": "https://w3id.org/dspace/v0.8/context.json",
"@type": "dspace:ContractNegotiation"
"@id": "urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3",
"dspace:state" :"REQUESTED"
}
Note that if the location header is not an absolute URL, it must resolve to an address that is relative to the base address of the request.
A consumer may make an offer by POSTing a ContractRequestMessage to negotiations/:id/request
:
POST https://connector.provider.com/negotiations/urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3/offers
Authorization: ...
{
"@context": "https://w3id.org/dspace/v0.8/context.jsonn",
"@type": "dspace:ContractRequestMessage",
"dspace:processId": "urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3",
"dspace:offer": {
"@type": "odrl:Offer",
"@id": "...",
"target": "urn:uuid:3dd1add8-4d2d-569e-d634-8394a8836a88"
}
}
The consumer must include the processId
. The consumer must include either the offer
or offerId
property.
If the message is successfully processed, the provider connector must return and HTTP 200 (OK) response. The response body is not specified and clients are not required to process it.
A consumer connector can POST a ContractNegotiationEventMessage to negotiations/:id/events
to accept the current
provider contract offer. If the negotiation state is successfully transitioned, the provider must return HTTP code 200 (OK). The response body is not specified and clients are not
required to process it.
If the current contract offer was created by the consumer, the provider must return HTTP code 400 (Bad Request) with an NegotiationErrorMessage
in the response body.
The consumer connector can POST a ContractAgreementVerificationMessage to verify an agreement. If the negotiation state is successfully transitioned, the provider must return HTTP code 200 (OK). The response body is not specified and clients are not required to process it.
POST https://connector.provider.com/negotiations/urn:uuid:a343fcbf-99fc-4ce8-8e9b-148c97605aab/agreement/verification
Authorization: ...
{
"@context": "https://w3id.org/dspace/v0.8/context.json",
"@type": "dspace:ContractAgreementVerificationMessage",
"dspace:processId": "urn:uuid:a343fcbf-99fc-4ce8-8e9b-148c97605aab",
"dspace:consumerSignature": {
"timestamp": 121212,
"hash": "....",
"signature": ""
}
}
The consumer connector can POST a ContractNegotiationTerminationMessage to terminate a negotiation. If the negotiation state is successfully transitioned, the provider must return HTTP code 200 (OK). The response body is not specified and clients are not required to process it.
All callback paths are relative to the callbackAddress
base URL specified in the ContractRequestMessage
that initiated a contract negotiation. For example, if
the callbackAddress
is specified as https://connector.consumer/callback
and a callback path binding is negotiations/:id/offers
, the resolved URL will
be https://connector.consumer.com/callback/negotiations/:id/offers
.
A provider may make an offer by POSTing a ContractOfferMessage to the negotiations/:id/offers
callback:
POST https://connector.consumer.com/callback/negotiations/urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3/offers
Authorization: ...
{
"@context": "https://w3id.org/dspace/v0.8/context.json",
"@type": "dspace:ContractOfferMessage",
"dspace:processId": "urn:uuid:dcbf434c-eacf-4582-9a02-f8dd50120fd3",
"dspace:offer": {
"@type": "odrl:Offer",
"@id": "...",
"target": "urn:uuid:3dd1add8-4d2d-569e-d634-8394a8836a88"
}
}
If the message is successfully processed, the consumer provider connector must return an HTTP 200 (OK) response. The response body is not specified and clients are not required to process it.
The provider connector can POST a ContractAgreementMessage to the negotiations/:id/agreement
callback to create an agreement. If the
negotiation state is successfully transitioned, the consumer must return HTTP code 200 (OK). The response body is not specified and clients are not required to process it.
POST https://connector.consumer.com/negotiations/urn:uuid:a343fcbf-99fc-4ce8-8e9b-148c97605aab/agreement
Authorization: ...
{
"@context": "https://w3id.org/dspace/v0.8/context.json",
"@type": "dspace:ContractAgreementMessage",
"dspace:processId": "urn:uuid:a343fcbf-99fc-4ce8-8e9b-148c97605aab",
"dspace:agreement": {
"@type": "odrl:Agreement",
"@id": "e8dc8655-44c2-46ef-b701-4cffdc2faa44",
"dspace:consumerId": "...",
"dspace:providerId": "...",
}
}
}
A provider can POST a ContractNegotiationEventMessage to the negotiations/:id/events
callback with an eventType
of finalized
to finalize a contract agreement. If the negotiation state is successfully transitioned, the consumer must return HTTP code 200 (OK). The response body is not
specified and clients are not required to process it.