How to interact with daml smart contracts through json api?

Tutorials and Guides
,
1 
module Main where

import Daml.Script

type AssetId = ContractId Asset

template Asset
  with
    issuer : Party
    owner  : Party
    name   : Text
  where
    ensure name /= ""
    signatory issuer
    observer owner
    choice Give : AssetId
      with
        newOwner : Party
      controller owner
      do create this with
           owner = newOwner

setup : Script AssetId
setup = script do
-- user_setup_begin
  alice <- allocatePartyWithHint "Alice" (PartyIdHint "Alice")
  bob <- allocatePartyWithHint "Bob" (PartyIdHint "Bob")
  aliceId <- validateUserId "alice"
  bobId <- validateUserId "bob"
  createUser (User aliceId (Some alice)) [CanActAs alice]
  createUser (User bobId (Some bob)) [CanActAs bob]
-- user_setup_end

  aliceTV <- submit alice do
    createCmd Asset with
      issuer = alice
      owner = alice
      name = "TV"

  bobTV <- submit alice do
    exerciseCmd aliceTV Give with newOwner = bob

  submit bob do
    exerciseCmd bobTV Give with newOwner = alice

" daml start "

daml damlc inspect-dar .\.daml\dist\ownership-0.0.1.dar --json


 "main_package_id": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4"

Payload for jwt.io

{
  "https://daml.com/ledger-api": {
    "ledgerId": "sandbox",
    "applicationId": "your-app-id",
    "actAs": [
      "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
    ],
    "readAs": [
      "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
    ],
    "admin": true
  }
}


Authorization : Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJodHRwczovL2RhbWwuY29tL2xlZGdlci1hcGkiOnsibGVkZ2VySWQiOiJzYW5kYm94IiwiYXBwbGljYXRpb25JZCI6InlvdXItYXBwLWlkIiwiYWN0QXMiOlsiQWxpY2U6OjEyMjA0MTg5NGM1OTQ2YzlhN2ZiYWRiNTk4MGU0MjEyNjkyYjA5MTVkNzVmZDRkZTQxNjNmZjdkOWM2ZTc5ZTFlMWRlIl0sInJlYWRBcyI6WyJCb2I6OjEyMjA0MTg5NGM1OTQ2YzlhN2ZiYWRiNTk4MGU0MjEyNjkyYjA5MTVkNzVmZDRkZTQxNjNmZjdkOWM2ZTc5ZTFlMWRlIl0sImFkbWluIjp0cnVlfX0.Sqd997oqXjWM6wTTQUG7HInFqD0rx3VrlykG0cKrKMc

Requests :

  1. Creating a contract

POST

http://localhost:7575/v1/create

payload :

{
    "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset",
    "payload": {
        "issuer": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
        "owner": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
        "name": "TV"
    }
}

Response :

{
    "result": {
        "agreementText": "",
        "completionOffset": "00000000000000000a",
        "contractId": "00797ddc13220046702b74e1eaf55023a71f01a42561ab64a8d5d2360895cf1a61ca0312200d1a0e344535911d18b09043d8a2027b967855c3346479411e7fa04df0b17542",
        "observers": [],
        "payload": {
            "issuer": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
            "owner": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
            "name": "TV"
        },
        "signatories": [
            "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
        ],
        "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"
    },
    "status": 200
}
  1. To retrieve users

GET

http://localhost:7575/v1/users

{
    "result": [
        {
            "primaryParty": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
            "userId": "alice"
        },
        {
            "primaryParty": "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
            "userId": "bob"
        },
        {
            "userId": "participant_admin"
        }
    ],
    "status": 200
}

3.Excersing a choice Give

POST

http://localhost:7575/v1/exercise

Payload :

{
    "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset",
    "contractId": "00797ddc13220046702b74e1eaf55023a71f01a42561ab64a8d5d2360895cf1a61ca0312200d1a0e344535911d18b09043d8a2027b967855c3346479411e7fa04df0b17542",
    "choice": "Give",
    "argument": {
        "newOwner": "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
    }
}

Response :

{
    "result": {
        "completionOffset": "00000000000000000b",
        "events": [
            {
                "archived": {
                    "contractId": "00797ddc13220046702b74e1eaf55023a71f01a42561ab64a8d5d2360895cf1a61ca0312200d1a0e344535911d18b09043d8a2027b967855c3346479411e7fa04df0b17542",
                    "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"
                }
            },
            {
                "created": {
                    "agreementText": "",
                    "contractId": "008e4cea3a383465d37719654916ad4494fd08b60bdeb5ddaa26475c28f3d12b82ca031220901cc80bc39af569a3211f495da024ae4d5c4d5e7e6640fc992198cd51b33209",
                    "observers": [
                        "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
                    ],
                    "payload": {
                        "issuer": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
                        "owner": "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
                        "name": "TV"
                    },
                    "signatories": [
                        "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
                    ],
                    "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"
                }
            }
        ],
        "exerciseResult": "008e4cea3a383465d37719654916ad4494fd08b60bdeb5ddaa26475c28f3d12b82ca031220901cc80bc39af569a3211f495da024ae4d5c4d5e7e6640fc992198cd51b33209"
    },
    "status": 200
}
  1. Fetch Contract by ID

POST

http://localhost:7575/v1/fetch

payload :

{
    "contractId": "008e4cea3a383465d37719654916ad4494fd08b60bdeb5ddaa26475c28f3d12b82ca031220901cc80bc39af569a3211f495da024ae4d5c4d5e7e6640fc992198cd51b33209",
    "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"
}

Response :

{
    "result": {
        "agreementText": "",
        "contractId": "008e4cea3a383465d37719654916ad4494fd08b60bdeb5ddaa26475c28f3d12b82ca031220901cc80bc39af569a3211f495da024ae4d5c4d5e7e6640fc992198cd51b33209",
        "observers": [
            "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
        ],
        "payload": {
            "issuer": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
            "owner": "Bob::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
            "name": "TV"
        },
        "signatories": [
            "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
        ],
        "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"
    },
    "status": 200
}
  1. Query contract by owner

POST

http://localhost:7575/v1/query

payload :

{
  "templateIds": ["fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"],
  "query": {
    "owner": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
  }
}

Response :

{
    "result": [
        {
            "agreementText": "",
            "contractId": "0027a89d25894149d7eb92720d30523687d46cdcbca55fa7bd02724e1575bebcc6ca0312202d4089b0f2fa5a871f5a86f0fc53c9ab94500a1d1ca56ec9dc73e5ac5f61fe99",
            "observers": [],
            "payload": {
                "issuer": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
                "owner": "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de",
                "name": "TV"
            },
            "signatories": [
                "Alice::122041894c5946c9a7fbadb5980e4212692b0915d75fd4de4163ff7d9c6e79e1e1de"
            ],
            "templateId": "fc3df5fd2d44c946c40646f04913f576d2707dade4f6fa1dcbec89f6895e68d4:Main:Asset"
        }
    ],
    "status": 200
}
1 Like
2

Hope this will be of help guys for beginners like me in daml .