Nexmo SMS API

Name: SMS API
Brand: SMS API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentCommunicationsSms MessagingapiKey1 EndpointsREST

For Agents

Send transactional and notification SMS messages from a Vonage virtual number or alphanumeric sender to E.164 phone numbers worldwide, with optional Unicode, binary, and delivery-receipt support.

Install Jentic One Beta

Connect the SMS API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the SMS API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with SMS API.

Send transactional SMS messages from a Vonage virtual number or alphanumeric sender ID to any E.164 mobile number

Deliver Unicode (UCS-2) text for non-Latin alphabets and emoji-bearing notifications

Send binary SMS payloads with user data header support for application-to-handset delivery

GET STARTED

Start building with SMS API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI specification for SMS API, keeping it validated and agent-ready. The Vonage SMS API sends one-way SMS messages from a Vonage virtual number or alphanumeric sender ID to mobile recipients in E.164 format, supporting text, Unicode, binary, WAP push, and vCard payloads. A single POST endpoint accepts the message, optional message class, status-report-request flag, callback URL, and TTL, returning delivery status and message reference IDs for each segment. API key and secret are passed as request parameters per Vonage's documented auth flow.

Use Cases

Patterns agents use SMS API for, with concrete tasks.

★ One-Time Password Delivery

Send numeric or alphanumeric OTP codes to customers during sign-up or step-up authentication. The single POST /{format} endpoint accepts to, from, and text fields and returns a per-segment delivery status. For locales requiring Unicode digits or non-Latin disclaimers, set type=unicode. Use a short time-to-live so codes that fail to deliver are not retried after they have expired in the application layer.

POST /json with to=+15551234567, from=Acme, text='Your code is 482913', and ttl=300000 to send a five-minute OTP and return the message reference

Operational Alert Notifications

Push deployment, monitoring, or on-call alerts directly to engineer mobile numbers. The SMS API takes the alert text and routes it through Vonage's global carrier network, with delivery receipt callbacks to a webhook so the alerting system can confirm receipt. Alphanumeric sender IDs make alerts identifiable in supported countries, while numeric senders are used where alphanumeric is restricted.

POST /json with to=+447700900123, from=Monitor, text='CPU at 95% on web-03', and status-report-req=1 to send the alert and request a delivery receipt

International Notification Campaign

Deliver order confirmations, shipping updates, and authentication messages to customers globally. The SMS API supports Unicode for international markets, message-class control for class 0 flash SMS, and client-ref tagging so each send can be reconciled against the source CRM record. Long messages are segmented automatically and the response lists each segment's delivery status.

POST /json with to=+819012345678, from=Shop, type=unicode, text containing the kana confirmation message, and client-ref='order-9821' to send a shipping update

AI Agent SMS Delivery

Through Jentic, an AI agent sends SMS without storing the Vonage API key or secret. The agent searches Jentic with the intent 'send an SMS message', loads the input schema for POST /{format}, and executes with to, from, and text. Jentic injects the API key and secret as request parameters from the MAXsystem vault, so the credentials never enter the agent's prompt context.

Use Jentic search query 'send an SMS message' to load POST /json, then execute with to, from, and text parameters to deliver a notification to a single recipient

Key Endpoints

1 endpoints — jentic publishes the only available openapi specification for sms api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/{format}

Send an SMS in JSON or XML response format

POST

/{format}

Send an SMS in JSON or XML response format

Why Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

Vonage api_key and api_secret are stored encrypted in the Jentic MAXsystem vault. Jentic injects them as request parameters at execution time, so the SMS API call carries valid credentials without exposing the secret to the agent.

Intent-based discovery

Agents search Jentic with the intent 'send an SMS message' and Jentic returns POST /{format} with its full input schema, so the agent populates to, from, and text without scraping Vonage docs.

Time to first call

Direct SMS API integration: a few hours to handle the credential parameters, response segments, and delivery receipt callback. Through Jentic: under 30 minutes to search, load, and execute the send operation.

FAQs

Specific to using SMS API through Jentic.

Why is there no official OpenAPI spec for SMS API?

Vonage does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call SMS API via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.

What authentication does the Vonage SMS API use?

The SMS API authenticates with your Vonage API key and API secret passed as api_key and api_secret request parameters on POST /{format}. Jentic stores both in the MAXsystem vault and injects them at execution time, so agents never handle the raw secret.

Can I send Unicode SMS for non-Latin alphabets?

Yes. Set type=unicode on POST /{format} to send UCS-2 encoded text for languages such as Japanese, Arabic, Hindi, or messages containing emoji. Note that Unicode segments hold 70 characters instead of 160, so longer messages will be split into multiple billed parts.

How do I receive delivery receipts for outbound SMS?

Set status-report-req=1 on the POST /{format} request and configure a delivery receipt callback URL in your Vonage account dashboard. Vonage will POST status updates to that URL once the carrier confirms delivery. Use the message-id field in the response to correlate receipts to the original send.

Can I send SMS from an alphanumeric sender ID?

Yes — pass an 11-character alphanumeric string in the from parameter on POST /{format}. Some destination countries (including the United States and Canada) require a numeric long code or short code instead, so check the Vonage country support matrix before relying on alphanumeric for global traffic.

How do I send an SMS through Jentic?

Run pip install jentic, then use the Jentic search query 'send an SMS message' to discover POST /{format}. Load the schema, then execute with to, from, and text — Jentic resolves the api_key and api_secret from the vault. Sign up at https://app.jentic.com/sign-up.