Nexmo SMS API

Name: SMS API
Brand: SMS API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentCommunicationsSms MessagingapiKey1 EndpointsREST

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

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.

Use for: I need to send a one-time password to a customer's phone, Send an SMS notification when a deployment finishes, Deliver a Unicode order confirmation to a Japanese phone number, Send a transactional SMS from an alphanumeric sender ID

Not supported: Does not handle inbound SMS reception, voice calls, or WhatsApp delivery - use for outbound SMS sending only.

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 your Jentic One instance, 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

Your Vonage api_key and api_secret are stored once, encrypted, by your own Jentic One instance and injected as request parameters at execution time. They never enter the agent's prompt, logs, or context.

Intent-based discovery

Agents search Jentic by intent such as 'send an SMS message' and Jentic returns the POST /{format} operation with its input schema so the agent populates to, from, and text without browsing the reference docs.

Time to first call

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 with Jentic One, the self-hosted execution layer.

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 your Jentic One instance 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. Run it through Jentic One, the self-hosted execution layer.

Can I limit what my agent is allowed to do with the Vonage SMS API?

Yes. Because Jentic One is self-hosted, your own rules decide which operations and credentials the agent may use, and this API exposes only a single outbound send operation, POST /{format}, so you choose whether that one send is in the agent's allowed set. The recipient number travels in the request body rather than the URL path, and your Vonage api_key and api_secret are injected at execution time, so the agent never handles the raw secret. If you leave the send operation out of the allowed set, the agent cannot dispatch any SMS.