Nexmo External Accounts API
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AI ReadinessAI-Aware (A-)71/100
Agent-ready OpenAPI document · curated by JenticCommunicationsChat Messagingbasic, bearer9 EndpointsREST
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For Agents
Manage Facebook Messenger, Viber Service Message, and WhatsApp sender accounts and link them to Nexmo applications so Messages and Dispatch can use them. Nine endpoints under /beta/chatapp-accounts.
Use for: Register a new Facebook Messenger page with Nexmo, Retrieve the WhatsApp account configured for sending business messages, Update the page access token for a Messenger account, Link a Viber Service Message account to a Nexmo application
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 specification for Nexmo External Accounts API, keeping it validated and agent-ready. The External Accounts API manages the per-channel chat-app identities that Nexmo's Messages and Dispatch APIs send through - Facebook Messenger pages, Viber Service Message senders, and WhatsApp business numbers. It exposes nine endpoints for creating Messenger accounts, retrieving Viber and WhatsApp account state, updating tokens, and linking or unlinking each account to a Nexmo application so that messages routed via that application can use the right sender identity.
Install Jentic One Beta
Connect the Nexmo External Accounts API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Nexmo External Accounts 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.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fnexmo.com%2Fnexmo-external-accounts" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fnexmo.com%2Fnexmo-external-accounts" | sh
jentic register # connects your agent to your Jentic One instanceJentic 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 External Accounts API.
Register a Facebook Messenger sender via POST /messenger with the page-id and a long-lived page access token
Retrieve a Messenger, Viber Service Message, or WhatsApp account by external_id via the matching GET endpoint
Update a Messenger account's name or token via PATCH /messenger/{external_id}
Delete a Messenger account via DELETE /messenger/{external_id}
Link a chat-app account to a Nexmo application via POST /{provider}/{external_id}/applications
Unlink an account from an application via DELETE /{provider}/{external_id}/applications/{application_id}
List every chat-app account the authenticated user owns via GET /
Use Cases
Patterns agents use Nexmo External Accounts API for, with concrete tasks.
★ Onboarding a Messenger page for outbound chat
Before sending a Facebook Messenger message via the Messages API, the page must be registered with Nexmo. POST /messenger creates the account with the Facebook page-id and a long-lived page access token, and POST /{provider}/{external_id}/applications then links the page to a Nexmo application so messages routed through that application use it as the sender.
POST /messenger with the page-id and page access token, then POST /messenger/{external_id}/applications with the target Nexmo application_id.
Token rotation for a WhatsApp or Messenger sender
Page access tokens and chat-app credentials expire. PATCH /messenger/{external_id} updates the stored token without recreating the account or relinking applications. Equivalent retrieval via GET /whatsapp/{external_id} and /viber_service_msg/{external_id} confirms the new state. The whole rotation is two HTTP calls.
PATCH /messenger/{external_id} with the new page access token, then GET /messenger/{external_id} to verify the updated state.
Application-scoped chat-app provisioning by an agent
An AI agent provisioning a new application can list existing chat-app accounts, register any missing ones, and link them all to the new application in a small batch of calls. Through Jentic the agent searches by intent ('link a chat-app account to a Nexmo application'), loads the link operation schema, and executes it once per provider/external_id pair.
GET / to list existing accounts, then for each missing provider call POST /messenger or rely on existing Viber/WhatsApp accounts and POST /{provider}/{external_id}/applications with the target application_id.
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 owned by the authenticated user
POST
/messenger
Create a Facebook Messenger account
PATCH
/messenger/{external_id}
Update a Messenger account's token or name
DELETE
/messenger/{external_id}
Delete a Messenger account
GET
/whatsapp/{external_id}
Retrieve a WhatsApp account by external_id
POST
/{provider}/{external_id}/applications
Link a chat-app account to a Nexmo application
DELETE
/{provider}/{external_id}/applications/{application_id}
Unlink a chat-app account from a Nexmo application
GET
/
List all chat-app accounts owned by the authenticated user
POST
/messenger
Create a Facebook Messenger account
PATCH
/messenger/{external_id}
Update a Messenger account's token or name
DELETE
/messenger/{external_id}
Delete a Messenger account
GET
/whatsapp/{external_id}
Retrieve a WhatsApp account by external_id
POST
/{provider}/{external_id}/applications
Link a chat-app account to a Nexmo application
DELETE
/{provider}/{external_id}/applications/{application_id}
Unlink a chat-app account from a Nexmo application
Jentic AI Readiness Score
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
E
External Accounts API
- AI-Aware (A-)71/100
100
Foundational Compliance73
Developer Experience & Jentic Compatibility59
AI-Readiness & Agent Experience94
Agent Usability43
Security100
AI DiscoverabilityPowered by JenticScoring Framework 1.0.0 | Scoring Engine 0.4.0
Show dimension breakdown
100
Foundational Compliance
Base layer of spec validity and structural soundness.
Grade: A+Signals: 4
98%
Lint Results
Aggregated quality score from linter diagnostics, weighted by severity.
100%
Resolution Completeness
Percentage of `$ref` references that resolve successfully.
100%
Specification Validity
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
100%
Structural Integrity
Structural correctness score based on schema issues using logarithmic dampening.
73
Developer Experience & Jentic Compatibility
Clarity, completeness, and ingestion readiness for developers and tooling.
Grade: A-Signals: 4
45%
Example Density
How richly the API is illustrated with examples.
97%
Example Validity
Percentage of examples that conform to their schemas.
50%
Response Coverage
Percentage of operations with complete response definitions (success, client error, server error).
100%
Tooling Readiness
Health of API ingestion, bundling, and resolution within Jentic pipelines.
59
AI-Readiness & Agent Experience
Semantic breadth, depth, and agent comprehension for AI systems.
Grade: C+Signals: 4
47%
Description Coverage
Coverage of descriptions across API elements.
33%
Error Standardization
Coverage of RFC 9457 Problem Details for error responses.
100%
OperationId Quality
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
56%
Summary Coverage
Coverage of summaries across operations/tags/info.
94
Agent Usability
Functional utility, complexity comfort, and AI orchestration readiness.
Grade: A+Signals: 1
94%
Complexity Comfort
Agent comfort level based on API operational and structural complexity.
43
Security
Trust, risk posture, and security compliance.
Grade: D-Signals: 1
42%
Authentication Strength
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
100
AI Discoverability
Findability, semantic richness, and reasoning readiness.
Grade: A+Signals: 1
100%
Descriptive Richness
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Nexmo External Accounts API by hand means supporting both HTTP basic and JWT bearer auth, minting per-call JWTs from your Application signing key, and routing account calls to the api.nexmo.com/beta/chatapp-accounts host. Through Jentic you install once, import the External Accounts API from the API Directory, store the credentials once, and your agent calls it.
Permission scoping
The External Accounts API puts the external account id in the URL path (/{provider}/{external_id}/...), so a rule can pin your agent to one chat-app sender account: it can read that account and link it to applications. You choose the operations it may call, so destructive ones like deleting a Messenger account or unlinking an application are not included unless you add them.
Credential isolation
Your Nexmo basic credentials and Application signing key are stored once, encrypted, by your own Jentic One instance and used to mint per-call JWTs at execution time. They never enter the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'link a chat-app account to a Nexmo application', and Jentic returns the matching operation among the endpoints with its parameter schema so the agent picks the right provider and method without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Nexmo External Accounts 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 with Jentic One, the self-hosted execution layer.
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 chooses per call so the agent never handles the page access tokens or signing keys directly.
Can I create a WhatsApp account through this API?
No. The spec exposes POST /messenger for creating Messenger accounts but only GET /whatsapp/{external_id} and GET /viber_service_msg/{external_id} for those providers. WhatsApp and Viber accounts are provisioned via the Vonage onboarding process and surface here for retrieval and application-linking only.
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. Account-level throttles apply, and chat-app account changes are typically infrequent operations.
How do I link a Messenger page 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=messenger, the page external_id, and the target application_id in the body.
How do I rotate a Messenger page access token without losing my application links?
PATCH /messenger/{external_id} updates only the token (and name). The links created via POST /{provider}/{external_id}/applications remain intact, so messages continue routing through the same Nexmo applications.
Can I limit what my agent is allowed to do with the Nexmo External Accounts API?
Yes. Because you run Jentic One yourself, your own rules decide which of the nine operations the agent may call and which credentials it may use. Since the external account id sits in the URL path (/{provider}/{external_id}/...), you can pin the agent to a single chat-app sender: for example allow it to read that account with GET /whatsapp/{external_id} and link it via POST /{provider}/{external_id}/applications, while withholding destructive calls like DELETE /messenger/{external_id} or unlinking an application. Only the operations you grant are ever exposed to the agent.
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