Server Frontend API Reference
While it's usually easiest to interact with Temporal Server via a Client SDK or the Temporal CLI, you can also use its gRPC API.
gRPC API
Our Client and Worker SDKs use the gRPC API. The API reference is located here:
Use with code
Usually you interact with the API via high-level methods like client.workflow.start(). However, Client SDKs also expose the underlying gRPC services. For instance, the TypeScript SDK has:
- WorkflowService: Client.connection.workflowService
- OperatorService: Client.connection.operatorService
- HealthService: Client.connection.healthService
If you're not using an SDK Client (rare), you can generate gRPC client stubs by:
- Cloning temporalio/api(repo with the protobuf files)
- Generating code in your language
Use manually
To query the API manually via command line or a GUI, first:
- If you don't already have a Server to connect to, run temporal server start-dev
- Clone this repo:
git clone https://github.com/temporalio/api.git
cd api
With command line
Install evans.
cd /path/to/api
evans --proto temporal/api/workflowservice/v1/service.proto --port 7233
To connect to Temporal Cloud, set the host, cert, cert key, and TLS flag:
evans --proto temporal/api/workflowservice/v1/service.proto --host devrel.a2dd6.tmprl.cloud --port 7233 --tls --cert /Users/me/certs/temporal.pem --certkey /Users/me/certs/temporal.key
Once inside the evans prompt, you can run commands like help, show service to list available methods, and call ListWorkflowExecutions.
With a GUI
- Install BloomRPC.
- Open the app
- Select "Import Paths" button on the top-left and enter the path to the cloned repo: /path/to/api
- Select the "Import protos" + button and select this file:
/path/to/api/temporal/api/workflowservice/v1/service.proto
- A list of methods should appear in the sidebar. Select one.
- Edit the JSON in the left pane.
- Hit Cmd/Ctrl-Enteror click the play button to get a response from the server on the right.
ListWorkflowExecutions

One downside compared to command line is it doesn't show enum names, just numbers like "task_queue_type": 1.
DescribeTaskQueue

HTTP API
The Web UI uses temporalio/ui-server, an HTTP proxy for the gRPC API.
As soon as this HTTP API proposal is implemented, it will be the recommended HTTP API, at which point the ui-server API may be discontinued. Further, ui-server was designed for use in the UI, and may make breaking changes.
To view the API docs, run temporal server start-dev and open:
To make a request, run:
$ curl localhost:8233/api/v1/namespaces/default/workflows
{
  "executions": [
    {
      "execution": {
        "workflowId": "workflow-_homozdkzYWLRpX6Rfou5",
        "runId": "c981cb26-baa4-4af8-ac5f-866451d3f83c"
      },
      "type": {
        "name": "example"
      },
      "startTime": ...
    },
    ...
  ],
  "nextPageToken": null
}
```
*/}