Nexmo Conversion API

Name: Nexmo Conversion API API
Brand: Nexmo Conversion API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentCommunicationsSms MessagingapiKey2 EndpointsREST

For Agents

Report SMS and voice 2FA conversion outcomes to Nexmo so its routing engine can learn which carriers actually deliver. Two POST endpoints: /sms and /voice.

Connect the Nexmo Conversion API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Nexmo Conversion 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.

Install Jentic One Beta (Self-Hosted)

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

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 Nexmo Conversion API API.

Report whether a 2FA SMS reached the user via POST /sms with the original message-id and a delivered timestamp

Report whether a 2FA voice call completed successfully via POST /voice with the call message-id

Improve future SMS and voice routing by feeding Nexmo's Adaptive Routing engine real conversion outcomes

Submit a delivered flag and ISO-8601 timestamp alongside each conversion to record when the user actually engaged

GET STARTED

Start building with Nexmo Conversion API API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for Nexmo Conversion API, keeping it validated and agent-ready.

Jentic publishes the only available OpenAPI specification for Nexmo Conversion API, keeping it validated and agent-ready. The Conversion API lets senders report whether a 2FA SMS or voice call ultimately reached and was acted on by the recipient. Nexmo (now Vonage) feeds these signals into its Adaptive Routing system, which continuously rebalances carrier paths to favour those producing higher real-world delivery success. The surface is intentionally tiny: two POST endpoints, one for SMS conversions and one for voice conversions.

Use Cases

Patterns agents use Nexmo Conversion API API for, with concrete tasks.

★ 2FA SMS conversion reporting

After a user enters a one-time code received by SMS, the application reports the outcome to Nexmo so its Adaptive Routing engine can prefer carriers that actually deliver. The Conversion API accepts the original message-id, a delivered boolean, and an optional ISO-8601 timestamp. There is a single POST /sms endpoint, and integration is typically a one-line call from the OTP verification handler.

POST to /sms with message-id from the original SMS send, delivered=true, and the current ISO-8601 timestamp using api_key and api_secret query parameters.

Voice OTP outcome logging

When a user receives a verification code by voice call, the application can report back whether the call connected and the code was used. POST /voice takes the same message-id, delivered, and timestamp shape as the SMS variant. This is the only voice-specific endpoint on the API and is used purely to improve future voice routing decisions.

POST to /voice with message-id from the original voice call response, delivered=true, and timestamp in ISO-8601 format.

Closing the loop on Verify flows from an agent

An AI agent that sends 2FA messages on behalf of a user can complete the loop by reporting the verification outcome through Jentic. After a Verify or Messages send, once the user enters the correct code, the agent issues a single conversion call so future sends route through better-performing carriers. Discovery is by intent ('report 2fa conversion'); execution is one POST per outcome.

Search Jentic for 'report 2fa conversion to nexmo', load the /sms operation schema, and execute it with the message-id, delivered=true, and current timestamp.

Key Endpoints

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

METHOD

PATH

DESCRIPTION

POST

/sms

Report whether an SMS message was successfully delivered

POST

/voice

Report whether a voice call was successfully delivered

POST

/sms

Report whether an SMS message was successfully delivered

POST

/voice

Report whether a voice call was successfully delivered

Why though Jentic?

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

Credential isolation

Nexmo api_key and api_secret are stored encrypted in the Jentic vault. Agents receive scoped execution access — the raw query-string credentials never enter the agent's context window or logs.

Intent-based discovery

Agents search by intent (e.g., 'report 2fa conversion to nexmo') and Jentic returns the matching POST /sms or POST /voice operation with its input schema, so the agent picks the right endpoint without reading developer.nexmo.com.

Time to first call

Direct integration: 1-2 hours for credential setup, request signing, and error handling. Through Jentic: under 10 minutes — search, load the schema, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Complementary

Nexmo Messages API

Sends the SMS, MMS, WhatsApp, Viber, and Messenger messages whose outcomes you then report through Conversion

Use Messages API to send the original 2FA message, then call Conversion to report whether the recipient acted on it.

Alternative

Twilio API

Twilio offers Verify and Messaging Insights as a competing approach to 2FA delivery and outcome tracking

Choose Twilio when the rest of the stack already runs on Twilio Verify and you want a single vendor for sending and analysing OTP traffic.

Alternative

MessageBird SMS API

MessageBird's SMS API is a direct competitor for transactional and 2FA SMS delivery in Europe

Pick MessageBird when European routing and a simpler pricing model matter more than Nexmo's Adaptive Routing feedback loop.

FAQs

Specific to using Nexmo Conversion API API through Jentic.

Why is there no official OpenAPI spec for Nexmo Conversion API?

Vonage (formerly Nexmo) does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Nexmo Conversion 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 Nexmo Conversion API use?

It accepts api_key and api_secret as query parameters, with an optional sig parameter for signed requests. Through Jentic these credentials are stored encrypted in the vault and injected at execution time, so the agent never sees raw account secrets.

Can I report both SMS and voice conversions through this API?

Yes. POST /sms reports SMS outcomes and POST /voice reports voice call outcomes. Both take the same body shape: message-id from the original send, a delivered boolean, and an optional ISO-8601 timestamp.

What are the rate limits for the Nexmo Conversion API?

The OpenAPI spec does not declare rate limits. Conversion reporting is generally low-volume relative to message sends, and Vonage applies account-level throttles documented at developer.nexmo.com rather than per-endpoint quotas.

How do I report a successful 2FA SMS through Jentic?

Search Jentic for 'report 2fa conversion to nexmo', load the POST /sms operation, and execute it with the message-id from your original Messages or SMS send response, delivered=true, and the timestamp at which the user verified.

Does this API affect billing or simply improve routing?

Conversion reporting does not generate charges or refunds. The data is used by Nexmo's Adaptive Routing system to choose better carriers on subsequent sends, so the financial impact is indirect via higher delivery rates.