Send an SMS through the API.

Before you start

• A Tremi workspace on Basic or a paid plan, and an owner or admin who can manage connections, publish workflows, and create API keys.
• Your own Twilio account with a Messaging Service. Connect it in Connections and confirm that the service appears among the imported resources.
• A terminal with cURL. Keep the API key in your local environment or server-side secret store.

This simulation sends no messages, uses 0 credits, and keeps results inside Tremi. To test external delivery, explicitly select a result webhook in the console simulation options.

Step 1

Publish one SMS attempt

Open Workflows, choose Create workflow, and enter these values:

Workflow name

Quickstart SMS

Workflow description

Open Workflow details, enter Send one test SMS and inspect its run evidence., then choose Save details.

Attempt

Choose Add attempt, select SMS, and select your Twilio Messaging Service.

Message

Hi {{first_name}}, this is your Tremi test message.

Timing

Keep the single attempt immediate, with no delay.

Variable

In Integrations → Workflow inputs, select first_name. Keep String, enter Recipient first name. as its description, use User as the example, and choose Save input.

Choose Review publish, then Publish v1. Publishing saves a fixed version; it does not send the message.

Open the workflow's API contract and check its slug. A new workflow named Quickstart SMS uses quickstart-sms; substitute your actual slug in the command below.

Step 2

Create an API key

In Settings → API keys, create a key with workflows:run and runs:read. Copy the secret when it appears, then replace the placeholder in your terminal:

export TREMI_API_KEY='<YOUR_KEY>'
export TREMI_WORKFLOW_SLUG='quickstart-sms'

workflows:run authorizes this REST simulation. The separate workflows:simulate scope is for MCP simulations.

Step 3

Simulate the run

Send the published workflow a recipient and the first_name variable. Keep mode set to simulation.

curl --request POST \
  "https://www.tremi.ai/api/v1/workflows/$TREMI_WORKFLOW_SLUG/runs" \
  --header "Authorization: Bearer $TREMI_API_KEY" \
  --header "Content-Type: application/json" \
  --header "Idempotency-Key: quickstart-sms-simulation-001" \
  --data '{
  "recipient": {
    "externalId": "quickstart-contact-001",
    "phone": "+15555550123",
    "timezone": "America/New_York"
  },
  "variables": {
    "first_name": "User"
  },
  "mode": "simulation"
}'

A successful request returns 202 Accepted with a run ID. Your ID and timestamp will differ:

Step 4

Inspect the result

Replace the placeholder with the returned run ID and retrieve its evidence:

export TREMI_RUN_ID='RUN_ID_FROM_THE_RESPONSE'

curl "https://www.tremi.ai/api/v1/runs/$TREMI_RUN_ID" \
  --header "Authorization: Bearer $TREMI_API_KEY"

The run completes asynchronously. If it is still queued or running, retrieve it again. For the one-step workflow above, expect these fields:

{
  "state": "completed",
  "outcome": "sequence_exhausted",
  "workflowVersion": 
   

Step 5

Send a live test

When the simulation looks right:

1. Confirm that Twilio is active, its Messaging Service has a sending number, and its messaging setup is ready for your test destination.
2. Replace the fictional phone number with a test number you control and are authorized to message. Set its actual time zone and the intended message variables.
3. Change mode to live and use a new idempotency key, such as quickstart-sms-live-001, before sending the request.
4. Retrieve the new run and inspect the actual provider evidence. Live SMS can wait for the recipient's sending window.

A live workflow start uses 1 Tremi credit. A provider-accepted SMS attempt uses 1 more; Twilio bills its usage separately.