canonical: https://jentic.com/apis/hilos.io/hilos

# Hilos API

Jentic publishes the only available OpenAPI specification for Hilos API, keeping it validated and agent-ready. Hilos is a WhatsApp Business messaging platform aimed at sales and support teams who run conversations at scale through the official WhatsApp Business API. The exposed surface is small but sharp: send a message, list messages, and list contacts, all authenticated with an API key in the Authorization header. Agents typically use Hilos to send templated outbound notifications and to read inbound replies for triage.

## For AI agents

Send and retrieve WhatsApp Business messages and look up contacts via Hilos. Authenticated with an API key in the Authorization header.

## Scope

Does not handle SMS, voice calls, or push notifications - use for WhatsApp Business messaging via Hilos only.

## Capabilities

- Send a WhatsApp message to a contact through POST /messages
- Retrieve message history with GET /messages for inbound triage and audit
- List Hilos contacts to choose recipients before sending
- Trigger templated outbound WhatsApp notifications from a backend job
- Pull inbound replies into an agent loop for response generation
- Audit conversation history by paging through /messages results

## Use cases

### WhatsApp Order Notifications

E-commerce teams send order confirmations and shipping updates over WhatsApp because open rates beat email. Hilos's POST /messages endpoint accepts a recipient and message body, so an agent can fire a notification from an order-events queue. Templates are managed in Hilos itself and selected by name in the message payload.

Example prompt: When an order is shipped, send a WhatsApp message via POST /messages to the customer's phone number with the shipping confirmation template.

### Sales Reply Triage

A sales team wants every inbound WhatsApp reply scored and routed. An agent polls GET /messages, classifies each new inbound message, and pushes high-intent leads into the CRM. Because the API surface is small, the integration is straightforward and most engineering effort goes into the classifier.

Example prompt: Every 5 minutes, fetch new messages from GET /messages, classify each as 'hot', 'warm', or 'spam', and push hot leads to the CRM.

### Customer Support Conversation History

Support agents need full message history when picking up a conversation. Hilos exposes /messages and /contacts so an interface can render the contact list and the historical thread for the selected customer, all driven by the API key configured for the workspace.

Example prompt: Given a contact ID from /contacts, fetch the last 50 messages from /messages filtered by that contact and render the thread.

### AI Agent WhatsApp Assistant

An AI agent answers customer questions over WhatsApp by consuming inbound messages via Hilos and replying with generated answers. Through Jentic, the agent searches for the send and list operations, loads their schemas, and executes them with the user's vault-stored Hilos API key.

Example prompt: When a new inbound message arrives, search Jentic for 'send a WhatsApp message via Hilos', generate an answer, and execute POST /messages to reply.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| POST | `/messages` | Send a WhatsApp message |
| GET | `/messages` | List messages and replies |
| GET | `/contacts` | List contacts in the workspace |

## Key resources

- **Messages** — Send outbound WhatsApp messages and list message history.
- **Contacts** — Retrieve the list of WhatsApp contacts in the workspace.

## Why Jentic

- **Setup:** Wiring the Hilos API by hand means managing an API key in the Authorization header and shaping WhatsApp message bodies with recipient and template fields. Through Jentic you install once, import the Hilos API from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** Hilos carries the recipient and contact in the request body rather than the URL path, so scoping stays at the operation level: limit the agent to the operations it needs, such as sending a WhatsApp message or listing contacts. You choose that set, so read-only listing can stand alone if you leave out the send operation.
- **Credential handling:** Your Hilos API key is stored once, encrypted, by your own Jentic One instance and injected into the Authorization header at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'send a WhatsApp message via Hilos', and Jentic returns the POST /messages operation with its body schema so the agent calls it with a recipient and template name without reading the reference docs.

## Related APIs

- **Twilio API** — Multi-channel messaging including WhatsApp, SMS, and voice with a much larger surface than Hilos.
- **MessageBird SMS API** — Multi-channel CPaaS provider with SMS-first heritage and a WhatsApp channel.
- **Sinch API** — Enterprise messaging and verification platform that pairs with Hilos for fallback channels.

## FAQ

### Why is there no official OpenAPI spec for Hilos API?

Hilos does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Hilos 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 Hilos API use?

The Hilos API uses an API key passed in the Authorization header. Through Jentic, your Hilos API key is held in your Jentic One instance and injected into the Authorization header at execution time, so the raw key never enters the agent context.

### Can I send WhatsApp messages with the Hilos API?

Yes. POST /messages sends an outbound WhatsApp message from your Hilos workspace to a contact. Templates are configured in the Hilos UI and referenced by name in the request payload to comply with WhatsApp Business policy.

### What are the rate limits for the Hilos API?

The Hilos OpenAPI specification does not declare rate limits, but WhatsApp Business itself enforces messaging tiers based on quality rating. Build retry-with-backoff and respect template restrictions to avoid having your number throttled by Meta.

### How do I read the latest replies through Jentic?

Run pip install jentic, then await client.search('list Hilos messages'), load the GET /messages schema, and execute it on a polling schedule. Persist the last seen message ID so you only process new inbound messages.

### Does Hilos handle SMS or voice as well as WhatsApp?

No. The Hilos API in this spec exposes WhatsApp messaging and contacts only. For SMS or voice you need a dedicated provider such as Twilio or MessageBird.

### Can I limit what my agent is allowed to do with the Hilos API?

Yes. Because Jentic One is self-hosted, you set the rules that decide which Hilos operations and credentials your agent may use. Hilos passes the recipient and contact in the request body rather than the URL, so scoping happens at the operation level: you pick the exact set from sending a WhatsApp message with POST /messages, listing message history with GET /messages, and listing contacts with GET /contacts. Leave out POST /messages and the agent gets read-only access to message history and contacts while your stored API key stays out of its context.