Nexmo External Accounts API

Name: Nexmo External Accounts API API
Brand: Nexmo External Accounts API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentCommunicationsChat Messagingbasic, bearer9 EndpointsREST

For Agents

Manage Facebook Messenger, Viber Service Message, and WhatsApp sender accounts and link them to Nexmo applications. Nine endpoints under /beta/chatapp-accounts.

Quickstart

Get started with Nexmo External Accounts 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:
"list nexmo chat-app accounts"

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

Capabilities

What an agent can do with Nexmo External Accounts API API.

List all chat-app accounts owned by the authenticated user via GET /

Create a Facebook Messenger sender via POST /messenger

Retrieve Messenger, Viber Service Message, or WhatsApp account state via the matching GET endpoint

Update a Messenger account's token via PATCH /messenger/{external_id}

GET STARTED

Start building with Nexmo External Accounts API API

Explore with Jentic

View OpenAPI Document

Use for: Register a Facebook Messenger page with Nexmo, Retrieve a WhatsApp account by external_id, Link a Viber Service Message account to a Nexmo application, List the chat-app accounts owned by this Nexmo user

Not supported: Does not send messages, manage WhatsApp templates, or onboard new WhatsApp/Viber numbers — use only to register, retrieve, and link Messenger/Viber/WhatsApp sender accounts to Nexmo applications.

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

Jentic publishes the only available OpenAPI specification for Nexmo External Accounts API, keeping it validated and agent-ready. This external-accounts-api slug is the alternate-named copy of Nexmo's chat-app account service. It exposes the same nine endpoints under /beta/chatapp-accounts for managing Facebook Messenger, Viber Service Message, and WhatsApp sender identities, plus the link/unlink operations that bind those identities to a Nexmo application so the Messages and Dispatch APIs route through the right sender.

Use Cases

Patterns agents use Nexmo External Accounts API API for, with concrete tasks.

★ Provisioning chat-app senders for a new Nexmo application

When a team spins up a new Nexmo application, they need to register or relink the chat-app accounts that will act as senders. POST /messenger registers a Messenger page; POST /{provider}/{external_id}/applications then links Messenger, Viber, or WhatsApp accounts to the application_id. The whole flow is a handful of calls.

POST /messenger to create the Messenger account, then POST /messenger/{external_id}/applications with application_id to bind it to the new Nexmo application.

Migrating chat-app senders between applications

When applications are split or merged, chat-app senders need to be unlinked from one application and linked to another. DELETE /{provider}/{external_id}/applications/{application_id} removes the old binding; POST /{provider}/{external_id}/applications creates the new one. Account state itself is preserved across the migration.

DELETE /messenger/{external_id}/applications/{old_app_id}, then POST /messenger/{external_id}/applications with the new application_id.

Agent-driven inventory and audit of chat-app accounts

An AI agent auditing a Nexmo tenant can list all chat-app accounts, fetch each account's full state, and check which applications they link to. Through Jentic the agent searches once for 'list chat-app accounts on nexmo' and walks through the GET endpoints without needing to hand-build base URL paths.

GET / to list all accounts, then for each account fetch GET /messenger/{external_id} or /whatsapp/{external_id} as appropriate to capture the linked applications.

Key Endpoints

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

METHOD

PATH

DESCRIPTION

GET

List all chat-app accounts the authenticated user owns

POST

/messenger

Create a Facebook Messenger account

PATCH

/messenger/{external_id}

Update a Messenger account

DELETE

/messenger/{external_id}

Delete a Messenger account

GET

/whatsapp/{external_id}

Retrieve a WhatsApp account

POST

/{provider}/{external_id}/applications

Link an account to a Nexmo application

DELETE

/{provider}/{external_id}/applications/{application_id}

Unlink an account from a Nexmo application

GET

List all chat-app accounts the authenticated user owns

POST

/messenger

Create a Facebook Messenger account

PATCH

/messenger/{external_id}

Update a Messenger account

DELETE

/messenger/{external_id}

Delete a Messenger account

GET

/whatsapp/{external_id}

Retrieve a WhatsApp account

Why though Jentic?

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

Credential isolation

Nexmo basic credentials, application signing keys, and Messenger page access tokens stay encrypted in the Jentic vault. Agents trigger operations via scoped execution that signs JWTs and assembles auth headers server-side.

Intent-based discovery

Agents search by intent (e.g., 'link a chat-app account to a Nexmo application') and Jentic returns the correct path among the nine endpoints with its parameter schema.

Time to first call

Direct integration: half a day to a day to wire up auth and the link/unlink flows. Through Jentic: under an hour.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Complementary

Nexmo Messages API

Sends Messenger, Viber, and WhatsApp messages through the senders managed here

After registering and linking accounts via this API, use Messages to send through them.

Complementary

Nexmo Application API v2

Manages the applications you bind chat-app accounts to

Create or list applications via Application API first, then bind chat-app accounts to them here.

Alternative

Twilio API

Twilio Conversations and Messaging Services cover similar sender management for Messenger and WhatsApp

Pick Twilio when the existing stack already uses Twilio Conversations or a unified Twilio Messaging Service.

FAQs

Specific to using Nexmo External Accounts API API through Jentic.

Why is there no official OpenAPI spec for Nexmo External Accounts 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 External Accounts 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 External Accounts API use?

Either HTTP basic auth (api_key/api_secret) or HTTP bearer with a JWT signed by an application's private key. Jentic stores both forms encrypted and injects them at execution time so the agent does not see Facebook page tokens or signing keys.

Can I create WhatsApp or Viber accounts via this API?

No. Only POST /messenger creates new accounts. WhatsApp and Viber Service Message senders are provisioned via Vonage onboarding and surface here through GET /whatsapp/{external_id} and GET /viber_service_msg/{external_id} for retrieval and application-linking.

What are the rate limits for the Nexmo External Accounts API?

The OpenAPI spec does not declare rate limits for the /beta/chatapp-accounts endpoints. Limits are imposed at account level by Vonage and these provisioning operations are typically very low frequency.

How do I link a chat-app account to a Nexmo application through Jentic?

Search Jentic for 'link a chat-app account to a Nexmo application', load POST /{provider}/{external_id}/applications, and execute with provider, external_id, and the target application_id.

How does this external-accounts-api slug differ from the external-accounts slug?

Both slugs index the same underlying API at /beta/chatapp-accounts with the same nine endpoints. The duplication exists from the original spec ingest; either slug resolves to the same operations.