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 back to Nexmo so the platform can tune routing and reliability for future verification traffic.

Quickstart

Get started with Nexmo Conversion API in minutes using your preferred integration method.

# Add to your MCP client config (Claude Desktop, Cursor, Windsurf)
{
  "jentic": {
    "url": "https://api.jentic.com/mcp",
    "auth": "oauth"
  }
}

# Then ask your agent:
"report sms 2fa conversion to nexmo"

# → Jentic returns the GET /events tool with parameter schema, agent executes.

Capabilities

What an agent can do with Nexmo Conversion API API.

Report whether a 2FA SMS code was successfully entered by the end user

Report whether a 2FA voice call code was successfully entered by the end user

Attach a delivery timestamp to each conversion record for accurate latency tracking

Tag SMS message-ids returned by the SMS API with conversion status to improve routing

GET STARTED

Start building with Nexmo Conversion API API

Explore with Jentic

View OpenAPI Document

Use for: I want to report a successful SMS 2FA verification back to Nexmo, Send conversion data for a voice OTP that the user completed, Confirm that a verification SMS message-id resulted in a real conversion, Mark a Nexmo voice call as not converted when the code was never entered

Not supported: Does not send messages, verify codes, or manage phone numbers — use for posting 2FA conversion outcomes back to Nexmo only.

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

The Nexmo Conversion API lets developers report back to Vonage whether a 2FA SMS or voice verification message was actually delivered and acted on by the recipient. Feeding this conversion signal back into the Nexmo platform helps optimise carrier routes, improve future delivery reliability, and surface fraudulent traffic patterns. The API exposes two simple POST endpoints, one for SMS and one for voice, each accepting a message-id, a delivered flag, and an optional timestamp.

Use Cases

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

★ 2FA SMS conversion feedback

When an application sends a 2FA code via the Nexmo SMS API, the Conversion API closes the loop by reporting whether the user actually entered the code. Posting a delivered=true or delivered=false flag against the original message-id lets Nexmo learn which carrier routes deliver real conversions versus silent failures, which directly improves future deliverability.

POST /sms with message-id from a previously sent verification SMS and delivered=true once the user submits the correct code

Voice OTP conversion tracking

Applications that deliver one-time passwords by automated voice call can report whether the recipient successfully entered the spoken code. The /voice endpoint accepts the call-id returned by the Voice API along with a delivered flag, allowing Nexmo to discriminate between answered-and-converted, answered-but-abandoned, and undelivered call outcomes.

POST /voice with the call-id from a Voice API verification call, delivered=true, and the timestamp the user completed the code

Routing optimisation feedback loop

Operations and trust teams send batch conversion updates back to Nexmo at the end of each verification session so the platform can recalculate carrier-route quality. Reporting both successful and failed conversions, rather than only successes, gives the routing engine balanced signal and reduces silent failure rates over time.

Loop through yesterday's verification messages and POST /sms or /voice for each with the appropriate delivered flag and timestamp

AI agent posting verification outcomes via Jentic

An AI agent that orchestrates a sign-up flow can call the Nexmo Conversion API through Jentic immediately after the user completes verification. Jentic handles the API key and secret, so the agent simply searches for the conversion operation, supplies the message-id and delivered flag, and Jentic executes the POST against api.nexmo.com/conversions.

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

Key Endpoints

2 endpoints — the nexmo conversion api lets developers report back to vonage whether a 2fa sms or voice verification message was actually delivered and acted on by the recipient.

METHOD

PATH

DESCRIPTION

POST

/sms

Report SMS 2FA conversion outcome

POST

/voice

Report voice OTP conversion outcome

POST

/sms

Report SMS 2FA conversion outcome

POST

/voice

Report voice OTP conversion outcome

Why though Jentic?

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

Credential isolation

Nexmo apiKey and apiSecret are stored encrypted in the Jentic vault. Agents receive scoped access tokens, so the raw secret never enters the agent's prompt or logs.

Intent-based discovery

Agents search Jentic by intent (e.g. 'report sms 2fa conversion') and Jentic returns the POST /sms or POST /voice operation with the input schema, ready to execute.

Time to first call

Direct integration: half a day to wire up apiKey/apiSecret handling and post-verify hooks. Through Jentic: under 15 minutes — search, load, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Complementary

Nexmo Verify API

Verify is the higher-level 2FA orchestration API whose verifications you would report back through Conversion.

Use Verify to send and check 2FA codes end-to-end; use Conversion to feed the outcome back into routing optimisation.

Complementary

Nexmo SMS API

The SMS API issues the message-ids that the Conversion API's /sms endpoint expects.

Send the verification SMS via the SMS API first, then post the resulting message-id to the Conversion API.

Alternative

Twilio Verify

Twilio's verification platform with built-in conversion analytics, available as an alternative provider.

Choose Twilio Verify if the project is already on Twilio infrastructure and wants conversion analytics in the same dashboard.

FAQs

Specific to using Nexmo Conversion API API through Jentic.

What authentication does the Nexmo Conversion API use?

The Conversion API uses Nexmo's standard apiKey and apiSecret query parameters, with optional apiSig for signed requests. Through Jentic these credentials live in the encrypted vault, so the agent only sees a scoped token and never the raw api_key or api_secret.

Can I report both SMS and voice conversions with the same API?

Yes. POST /sms accepts message-ids returned by the Nexmo SMS API and POST /voice accepts call-ids returned by the Nexmo Voice API. Both endpoints share the same delivered flag and timestamp parameters, so a single integration covers both verification channels.

What are the rate limits for the Nexmo Conversion API?

Vonage does not publish a hard per-second rate limit for the Conversion API and the OpenAPI spec does not encode one. In practice the endpoint is designed to absorb post-hoc batch reporting, so spreading conversion posts over the same window in which messages were sent is the safest pattern.

How do I report a converted SMS through Jentic?

Run pip install jentic, search for 'report sms 2fa conversion to nexmo', load the POST /sms operation, and execute with message-id, delivered=true, and an optional timestamp. Jentic injects the apiKey credentials and returns the Nexmo response.

Is the Nexmo Conversion API free?

Reporting conversion data does not incur a per-call charge from Vonage; the cost sits with the underlying SMS or voice verification message you originally sent. Only customers already using the Nexmo SMS or Voice APIs would have message-ids to report against.

Should I report failed conversions as well as successful ones?

Yes. Sending only delivered=true skews the routing engine because Nexmo cannot distinguish silent failures from messages you simply never followed up on. Posting delivered=false for OTPs that were never entered gives the platform balanced signal.