Documentation

Cadence HTTP API

Overview

Cadence HTTP API allows users to interact with the Cadence server using the HTTP protocol. You can leverage this functionality to initiate or terminate workflows from your bash scripts, monitor the status of your cluster, or execute any other operation that the Cadence RPC declaration supports.

Cadence HTTP API is provided via port 8800 and only available from Cadence v1.2.2.

To create a Cadence cluster with HTTP API enabled, please check out Creating a Cadence Cluster with HTTP API.

Examples

Curl command

You can run the following curl command to start a dummy workflow in the Cadence server assuming the domain sample-domain has already been created.

curl -X POST http://<load balancer address or node IP>:8800 \
    -H 'context-ttl-ms: 2000' \
    -H 'rpc-caller: curl-client' \
    -H 'rpc-service: cadence-frontend' \
    -H 'rpc-encoding: json' \
    -H 'rpc-procedure: uber.cadence.api.v1.WorkflowAPI::StartWorkflowExecution' \
    -d \
    '{
      "domain": "sample-domain",
      "workflow_id": "sample-workflow-id",
      "execution_start_to_close_timeout": "61s",
      "task_start_to_close_timeout": "60s",
      "workflow_type": {
        "name": "sample-workflow-type"
      },
      "task_list": {
        "name": "sample-task-list"
      },
      "identity": "client-name-visible-in-history",
      "request_id": "8049B932-6C2F-415A-9BB2-241DCF4CFC9C",
      "input": {
        "data": "IkN1cmwhIg=="
      }
    }'

curl -X POST http://<load balancer address or node IP>:8800 \

-H 'context-ttl-ms: 2000' \

-H 'rpc-caller: curl-client' \

-H 'rpc-service: cadence-frontend' \

-H 'rpc-encoding: json' \

-H 'rpc-procedure: uber.cadence.api.v1.WorkflowAPI::StartWorkflowExecution' \

-d \

"domain": "sample-domain",

"workflow_id": "sample-workflow-id",

"execution_start_to_close_timeout": "61s",

"task_start_to_close_timeout": "60s",

"workflow_type": {

"name": "sample-workflow-type"

"task_list": {

"name": "sample-task-list"

"identity": "client-name-visible-in-history",

"request_id": "8049B932-6C2F-415A-9BB2-241DCF4CFC9C",

"input": {

"data": "IkN1cmwhIg=="

}

Python

The following Python script starts a dummy workflow in the sample-domain as well.

import requests

url = "http://<load balancer address or node IP>:8800"

payload = {
    "domain": "sample-domain",
    "workflow_id": "sample-workflow-id",
    "execution_start_to_close_timeout": "10s",
    "task_start_to_close_timeout": "5s",
    "workflow_type": {"name": "sample-workflow-type"},
    "task_list": {"name": "sample-task-list"},
    "identity": "sample-worker",
    "request_id": "8049B932-6C2F-415A-9BB2-241DCF4CFC9C"
}

headers = {
    "Content-Type": "application/json",
    "context-ttl-ms": "2000",
    "rpc-caller": "curl-client",
    "rpc-service": "cadence-frontend",
    "rpc-encoding": "json",
    "rpc-procedure": "uber.cadence.api.v1.WorkflowAPI::StartWorkflowExecution"
}

response = requests.post(url, json=payload, headers=headers)

data = response.json()
print(data)

import requests

url = "http://<load balancer address or node IP>:8800"

payload = {

"domain": "sample-domain",

"workflow_id": "sample-workflow-id",

"execution_start_to_close_timeout": "10s",

"task_start_to_close_timeout": "5s",

"workflow_type": {"name": "sample-workflow-type"},

"task_list": {"name": "sample-task-list"},

"identity": "sample-worker",

"request_id": "8049B932-6C2F-415A-9BB2-241DCF4CFC9C"

}

headers = {

"Content-Type": "application/json",

"context-ttl-ms": "2000",

"rpc-caller": "curl-client",

"rpc-service": "cadence-frontend",

"rpc-encoding": "json",

"rpc-procedure": "uber.cadence.api.v1.WorkflowAPI::StartWorkflowExecution"

}

response = requests.post(url, json=payload, headers=headers)

data = response.json()

print(data)

C#

You can also use C# to start a dummy workflow in the sample-domain.

using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;

class StartWorkflowExecution
{
    static async Task Main()
    {
        string url = "http://<load balancer address or node IP>:8800";

        var payload = new
        {
            domain = "sample-domain",
            workflow_id = "sample-workflow-id",
            execution_start_to_close_timeout = "10s",
            task_start_to_close_timeout = "5s",
            workflow_type = new { name = "sample-workflow-type" },
            task_list = new { name = "sample-task-list" },
            identity = "sample-worker",
            request_id = "8049B932-6C2F-415A-9BB2-241DCF4CFC9C"
        };

        var headers = new
        {
            Content_Type = "application/json",
            context_ttl_ms = "2000",
            rpc_caller = "curl-client",
            rpc_service = "cadence-frontend",
            rpc_encoding = "json",
            rpc_procedure = "uber.cadence.api.v1.WorkflowAPI::StartWorkflowExecution"
        };

        var jsonPayload = JsonSerializer.Serialize(payload);
        var httpContent = new StringContent(jsonPayload, Encoding.UTF8, headers.Content_Type);

        httpContent.Headers.Add("context-ttl-ms", headers.context_ttl_ms);
        httpContent.Headers.Add("rpc-caller", headers.rpc_caller);
        httpContent.Headers.Add("rpc-service", headers.rpc_service);
        httpContent.Headers.Add("rpc-encoding", headers.rpc_encoding);
        httpContent.Headers.Add("rpc-procedure", headers.rpc_procedure);

        var client = new HttpClient();
        var response = await client.PostAsync(url, httpContent);

        if (response.IsSuccessStatusCode)
        {
            var responseContent = await response.Content.ReadAsStringAsync();
            var data = JsonSerializer.Deserialize<object>(responseContent);
            Console.WriteLine(data);
        }
    }
}

using System;

using System.Net.Http;

using System.Text;

using System.Text.Json;

using System.Threading.Tasks;

class StartWorkflowExecution

{

static async Task Main()

{

string url = "http://<load balancer address or node IP>:8800";

var payload = new

{

domain = "sample-domain",

workflow_id = "sample-workflow-id",

execution_start_to_close_timeout = "10s",

task_start_to_close_timeout = "5s",

workflow_type = new { name = "sample-workflow-type" },

task_list = new { name = "sample-task-list" },

identity = "sample-worker",

request_id = "8049B932-6C2F-415A-9BB2-241DCF4CFC9C"

};

var headers = new

{

Content_Type = "application/json",

context_ttl_ms = "2000",

rpc_caller = "curl-client",

rpc_service = "cadence-frontend",

rpc_encoding = "json",

rpc_procedure = "uber.cadence.api.v1.WorkflowAPI::StartWorkflowExecution"

};

var jsonPayload = JsonSerializer.Serialize(payload);

var httpContent = new StringContent(jsonPayload, Encoding.UTF8, headers.Content_Type);

httpContent.Headers.Add("context-ttl-ms", headers.context_ttl_ms);

httpContent.Headers.Add("rpc-caller", headers.rpc_caller);

httpContent.Headers.Add("rpc-service", headers.rpc_service);

httpContent.Headers.Add("rpc-encoding", headers.rpc_encoding);

httpContent.Headers.Add("rpc-procedure", headers.rpc_procedure);

var client = new HttpClient();

var response = await client.PostAsync(url, httpContent);

if (response.IsSuccessStatusCode)

{

var responseContent = await response.Content.ReadAsStringAsync();

var data = JsonSerializer.Deserialize<object>(responseContent);

Console.WriteLine(data);

}

HTTP API Endpoints

Following are the HTTP API endpoints currently supported in our managed Cadence service. For more information about Cadence HTTP API, please check out the Cadence HTTP API documentation.