canonical: https://jentic.com/apis/callloop.com/callloop

# CallLoop API

The CallLoop API sends SMS, voice, and ringless voicemail messages from your own number and manages the contacts and lists behind them. A send is accepted and queued, then you poll the message by id until it reaches a terminal delivery status. Contacts and lists support bulk operations, do-not-call verification, and audio-file management for voice and ringless messages.

## For AI agents

Send SMS, voice, and ringless voicemail, then poll delivery status. Manage contacts and lists in bulk and verify them against do-not-call records.

## Scope

Does not handle email delivery, RCS messaging, or payment processing. Use for SMS, voice, and ringless messaging with contact and list management only.

## Capabilities

- Send SMS, voice, and ringless voicemail messages from your own number
- Poll a message by id until it reaches a terminal delivery status
- Add and remove contacts and lists, including bulk subscribe and unsubscribe
- Verify contacts and lists against do-not-call records
- Upload and replace audio files for voice and ringless messages
- Search contacts and lists and read list statistics

## Use cases

### Agent-sent SMS with delivery tracking

An AI agent can send an SMS from the account's own number, receive a queued status with a message id, then poll that id until it reaches a terminal status such as Delivered or Failed. The agent never treats a queued response as proof of delivery.

Example prompt: Send an SMS to +15551234567 from the account number and poll the message id until it is delivered

### Bulk contact list management

A campaign agent can add contacts to a list in bulk, verify the list against do-not-call records, and read list statistics before a broadcast, so a send never reaches a number on a suppression list. Bulk subscribe, unsubscribe, archive, and delete are each available.

Example prompt: Add a batch of contacts to a list, verify the list against do-not-call records, and read its statistics

### Voice and ringless campaigns

A voice-outreach agent can upload an audio file, send it as a voice message or ringless voicemail to a list, and poll each message for delivery. Audio files can be replaced and checked for existence by name before a campaign.

Example prompt: Upload an audio file, send it as a ringless voicemail to a contact, and poll the message until it completes

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| POST | `/api/public/v1/message/sms` | Send an SMS message |
| POST | `/api/public/v1/message/ringless` | Send a ringless voicemail |
| GET | `/api/public/v1/message/{id}` | Get a message by id or state UUID |
| POST | `/api/public/v1/contacts/bulk/add-to-lists` | Add contacts to lists in bulk |
| POST | `/api/public/v1/lists/verify-dnc` | Verify lists against do-not-call records |
| POST | `/api/public/v1/audio/upload` | Upload an audio file |

## Key resources

- **Messages** — Send SMS, voice, and ringless messages and poll delivery status
- **Contacts** — Create, search, and bulk-manage contacts and their subscription status
- **Lists** — Create lists, verify against do-not-call records, and read statistics
- **Audio** — Upload, replace, and manage audio files for voice and ringless messages

## AI readiness

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.

- **Score:** 60 / 100
- **Maturity:** AI-Aware
- **Dimensions:**
  - Foundational Compliance: 99 / 100
  - Developer Experience & Jentic Compatibility: 55 / 100
  - AI-Readiness & Agent Experience: 38 / 100
  - Agent Usability: 94 / 100
  - Security: 60 / 100
  - AI Discoverability: 79 / 100
- **View full report:** https://jentic.com/apis/callloop.com/callloop/scorecard
- **How the score is calculated:** https://docs.jentic.com/reference/api-readiness-framework/overview/
- **More about the dimensions:** https://docs.jentic.com/reference/api-readiness-framework/specification/#dimensional-model-overview

### Score it yourself

Every API in the directory is allowlisted, so you can re-score it with no key required.

- **Score your own API:** https://jentic.com/scorecard.md
- **Scoring CLI agent skill:** https://github.com/jentic/jentic-api-scorecard/blob/main/skills/jentic-api-scorecard/SKILL.md

```sh
npx @jentic/api-scorecard-cli score <openapi-url>
```

## Why Jentic

- **Setup:** Wiring CallLoop by hand means handling its personal-access-token bearer auth with the required prefix, and the send-then-poll pattern where a queued status is not a delivery. Through Jentic you install once, import CallLoop from the API Directory, store the token once, and your agent calls it.
- **Permission scoping:** You choose which CallLoop operations the agent may call, such as sending messages and polling status, so bulk operations like deleting contacts are not included unless you add them.
- **Credential handling:** Your CallLoop token is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'send an SMS message', and Jentic returns the matching CallLoop operation with its input schema so the agent calls the right endpoint without browsing the docs.

## Related APIs

- **Plivo** — Plivo sends SMS and voice globally; CallLoop adds ringless voicemail and list management.
- **Telnyx** — Telnyx is a programmable SMS and voice platform; CallLoop targets list-based broadcasts.
- **ClickSend** — ClickSend sends SMS, voice, and more from lists; CallLoop focuses on SMS, voice, and ringless.
- **TextMagic** — TextMagic is an SMS marketing platform; CallLoop adds ringless voicemail alongside SMS and voice.

## FAQ

### What authentication does the CallLoop API use?

The CallLoop API authenticates with a personal access token sent as a bearer token in the Authorization header, per its OpenAPI spec. The token carries contact and message read or write scopes, and the required prefix must be kept intact.

### Is there a CallLoop MCP server?

You do not need an MCP server to give your agent CallLoop. Jentic connects it directly from the API Directory: import it, store your token once, and your agent calls the message, contact, and list operations without loading another server's tool definitions into its context.

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

Yes. Write a rule that allows only the message-send and status-poll operations, so the agent can send and track messages but cannot bulk-delete contacts or lists until you add those operations, and every call it makes is logged.

### Can I check message delivery status with the CallLoop API?

Yes. A send returns a queued status with a message id, and the message endpoint lets you poll that id or its state UUID until it reaches a terminal status such as Delivered, Sent, or Failed.

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

The OpenAPI spec does not publish a numeric rate limit. The gateway returns HTTP 429 when the organization exceeds its request quota, and per-number sending may be throttled separately.

### How do I send an SMS with the CallLoop API through Jentic?

Search Jentic for 'send an SMS message', and it returns the CallLoop send-SMS operation with its input schema. Send from a number on your account, then poll the returned message id until it reaches a terminal status. To run it on your own infrastructure, install Jentic One from its GitHub repo.