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POST
/
v2
/
interactive-submission
/
prepare
/v2/interactive-submission/prepare
curl --request POST \
  --url https://api.example.com/v2/interactive-submission/prepare \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "commandId": "<string>",
  "commands": [
    {
      "CreateAndExerciseCommand": {
        "templateId": "<string>",
        "createArguments": "<unknown>",
        "choice": "<string>",
        "choiceArgument": "<unknown>"
      }
    }
  ],
  "actAs": [
    "<string>"
  ],
  "userId": "<string>",
  "minLedgerTime": {
    "time": {
      "Empty": {}
    }
  },
  "readAs": [
    "<string>"
  ],
  "disclosedContracts": [
    {
      "createdEventBlob": "<string>",
      "templateId": "<string>",
      "contractId": "<string>",
      "synchronizerId": "<string>"
    }
  ],
  "synchronizerId": "<string>",
  "packageIdSelectionPreference": [
    "<string>"
  ],
  "verboseHashing": true,
  "prefetchContractKeys": [
    {
      "templateId": "<string>",
      "contractKey": "<unknown>"
    }
  ],
  "maxRecordTime": "<string>",
  "estimateTrafficCost": {
    "disabled": true,
    "expectedSignatures": [
      "SIGNING_ALGORITHM_SPEC_UNSPECIFIED"
    ]
  },
  "tapsMaxPasses": 123,
  "hashingSchemeVersion": "HASHING_SCHEME_VERSION_UNSPECIFIED"
}
'
{
  "preparedTransaction": "<string>",
  "preparedTransactionHash": "<string>",
  "hashingSchemeVersion": "HASHING_SCHEME_VERSION_UNSPECIFIED",
  "hashingDetails": "<string>",
  "costEstimation": {
    "estimationTimestamp": "<string>",
    "confirmationRequestTrafficCostEstimation": 123,
    "confirmationResponseTrafficCostEstimation": 123,
    "totalTrafficCostEstimation": 123
  }
}

Documentation Index

Fetch the complete documentation index at: https://docs.canton.network/llms.txt

Use this file to discover all available pages before exploring further.

Authorizations

​
Authorization
string
header
required

Ledger API standard JWT token

Body

application/json
​
commandId
string
required

Uniquely identifies the command. The triple (user_id, act_as, command_id) constitutes the change ID for the intended ledger change, where act_as is interpreted as a set of party names. The change ID can be used for matching the intended ledger changes with all their completions. Must be a valid LedgerString (as described in value.proto).

Required

​
commands
Command · object[]
required

Individual elements of this atomic command. Must be non-empty. Limitation: Only single command transaction are currently supported by the API. The field is marked as repeated in preparation for future support of multiple commands.

Required: must be non-empty

A command can either create a new contract or exercise a choice on an existing contract.

​
actAs
string[]
required

Set of parties on whose behalf the command should be executed, if submitted. If ledger API authorization is enabled, then the authorization metadata must authorize the sender of the request to read (not act) on behalf of each of the given parties. This is because this RPC merely prepares a transaction and does not execute it. Therefore read authorization is sufficient even for actAs parties. Note: This may change, and more specific authorization scope may be introduced in the future. Each element must be a valid PartyIdString (as described in value.proto).

Required: must be non-empty

​
userId
string

Uniquely identifies the participant user that prepares the transaction. Must be a valid UserIdString (as described in value.proto). Required unless authentication is used with a user token. In that case, the token's user-id will be used for the request's user_id.

Optional

​
minLedgerTime
MinLedgerTime · object

Optional

​
readAs
string[]

Set of parties on whose behalf (in addition to all parties listed in act_as) contracts can be retrieved. This affects Daml operations such as fetch, fetchByKey, lookupByKey, exercise, and exerciseByKey. Note: A command can only use contracts that are visible to at least one of the parties in act_as or read_as. This visibility check is independent from the Daml authorization rules for fetch operations. If ledger API authorization is enabled, then the authorization metadata must authorize the sender of the request to read contract data on behalf of each of the given parties.

Optional: can be empty

​
disclosedContracts
DisclosedContract · object[]

Additional contracts used to resolve contract & contract key lookups.

Optional: can be empty

​
synchronizerId
string

Must be a valid synchronizer id If not set, a suitable synchronizer that this node is connected to will be chosen

Optional

​
packageIdSelectionPreference
string[]

The package-id selection preference of the client for resolving package names and interface instances in command submission and interpretation

Optional: can be empty

​
verboseHashing
boolean

When true, the response will contain additional details on how the transaction was encoded and hashed This can be useful for troubleshooting of hash mismatches. Should only be used for debugging. Defaults to false

Optional

​
prefetchContractKeys
PrefetchContractKey · object[]

Fetches the contract keys into the caches to speed up the command processing. Should only contain contract keys that are expected to be resolved during interpretation of the commands. Keys of disclosed contracts do not need prefetching.

Optional: can be empty

​
maxRecordTime
string

Maximum timestamp at which the transaction can be recorded onto the ledger via the synchronizer specified in the PrepareSubmissionResponse. If submitted after it will be rejected even if otherwise valid, in which case it needs to be prepared and signed again with a new valid max_record_time. Use this to limit the time-to-life of a prepared transaction, which is useful to know when it can definitely not be accepted anymore and resorting to preparing another transaction for the same intent is safe again.

Optional

​
estimateTrafficCost
CostEstimationHints · object

Hints to improve the accuracy of traffic cost estimation. The estimation logic assumes that this node will be used for the execution of the transaction If another node is used instead, the estimation may be less precise. Request amplification is not accounted for in the estimation: each amplified request will result in the cost of the confirmation request to be charged additionally.

Traffic cost estimation is enabled by default if this field is not set To turn off cost estimation, set the CostEstimationHints#disabled field to true

Optional

​
tapsMaxPasses
integer<int32>

The maximum number of passes for the Topology-Aware Package Selection (TAPS). Higher values can increase the chance of successful package selection for routing of interpreted transactions. If unset, this defaults to the value defined in the participant configuration. The provided value must not exceed the limit specified in the participant configuration.

Optional

​
hashingSchemeVersion
enum<string>

The hashing scheme version to be used when building the hash. Defaults to HASHING_SCHEME_VERSION_V2.

Optional

Available options:
HASHING_SCHEME_VERSION_UNSPECIFIED,
HASHING_SCHEME_VERSION_V2,
HASHING_SCHEME_VERSION_V3

Response

[docs-entry-end: HashingSchemeVersion]

​
preparedTransaction
string
required

The interpreted transaction, it represents the ledger changes necessary to execute the commands specified in the request. Clients MUST display the content of the transaction to the user for them to validate before signing the hash if the preparing participant is not trusted.

Required

​
preparedTransactionHash
string
required

Hash of the transaction, this is what needs to be signed by the party to authorize the transaction. Only provided for convenience, clients MUST recompute the hash from the raw transaction if the preparing participant is not trusted. May be removed in future versions

Required: must be non-empty

​
hashingSchemeVersion
enum<string>
required

The hashing scheme version used when building the hash

Required

Available options:
HASHING_SCHEME_VERSION_UNSPECIFIED,
HASHING_SCHEME_VERSION_V2,
HASHING_SCHEME_VERSION_V3
​
hashingDetails
string

Optional additional details on how the transaction was encoded and hashed. Only set if verbose_hashing = true in the request Note that there are no guarantees on the stability of the format or content of this field. Its content should NOT be parsed and should only be used for troubleshooting purposes.

Optional

​
costEstimation
CostEstimation · object

Traffic cost estimation of the prepared transaction

Optional