SMS API for two-way AI agent conversations
Claw Messenger gives AI agents one API for two-way iMessage, RCS, and SMS conversations. An agent sends a message to a registered phone number, receives a send status, and listens for the person's reply. For a first test, let the API choose the available channel and confirm the reply reaches your agent. See the API docs and channel guidance.
When does an SMS API fit an AI agent?
An SMS API fits when your agent needs to send a phone message and act on the response. The useful result is a complete conversation: the outbound request, its status, and an inbound message routed to the right agent. Claw Messenger supports SMS alongside iMessage and RCS, with managed messaging infrastructure and REST or WebSocket access for agents running without a Mac. Product overview · API docs.
Claw is designed for registered contacts and ongoing conversations. It is not a bulk cold-outreach tool: self-serve plans have monthly message allowances and a separate safeguard for new recipients. Plans and limits.
What does the agent send, and what comes back?
The input is an authenticated agent request with a recipient phone number and message text. Register the phone number first for a controlled test, and connect a WebSocket listener before sending. The send response reports a status such as accepted, failed, or not_confirmed; later status events can report delivery evidence. A person's response arrives separately as an inbound message event. API docs.
That distinction matters. accepted means the send process started. Even a delivery receipt does not show that the agent can receive a reply. The test is complete when the response from the same phone reaches the connected agent or WebSocket consumer. Delivery-status reference.
Should you choose Claw Messenger or a general SMS platform?
Choose by the channels and integration you need. A general programmable SMS platform can also send messages, report status, and receive replies; those are not exclusive Claw features. Twilio's SMS documentation, for example, describes inbound webhooks and outbound status callbacks. Twilio messaging webhooks.
| Approach | Message path | How replies reach your agent | Fits when |
|---|---|---|---|
| Claw Messenger | One agent API supports iMessage, RCS, and SMS; its first-test guidance leaves channel selection to the service. | Self-serve inbound messages go to a persistent WebSocket listener. | You want managed, reply-backed agent conversations across those phone channels. |
| Programmable SMS through Twilio | Your application uses Twilio's SMS API and messaging setup. | You configure an inbound webhook and connect it to your agent; outbound status callbacks are separate. | You want to build an SMS-specific workflow around your own webhook endpoint. |
If you only need SMS and already operate its webhook flow, a general SMS platform may be the simpler fit. If you want an agent-facing API with iMessage and RCS available as well, Claw avoids building a separate SMS-only route for that same conversation. This is an integration choice, not a claim that every recipient will get a particular channel. Claw API docs · Twilio messaging webhooks.
For the neighboring channel decision, see the iMessage API guide; the API docs cover RCS and automatic routing within the same integration.
How do you prove the first conversation works?
Follow the direct API quickstart:
- Choose a plan, create an API key, and register a phone number you control.
- Connect the agent's WebSocket listener and check readiness before sending.
- Send one plain message to that phone. Leave
serviceunset for the first test so Claw can choose the available route. - Reply from the same phone and thread. Confirm the inbound
messageevent reaches the agent.
If you specifically need to test SMS, the API documents SMS as a service value. An explicit request can still fall back to automatic routing, so inspect the returned channel and the actual reply before claiming the test used SMS. Sending and status reference · First-test guidance.
What plan or account fits?
Self-serve plans start at $5 per month for 250 incoming and outgoing messages and one registered number. Higher plans increase both allowances. A seven-day self-serve trial requires a card. Current pricing.
Agencies needing separate client workspaces can request Agency review. The published offer is $199 monthly per provisioned subtenant, with 1,000 messages included and a one-time $250 parent onboarding fee. Each provisioned subtenant has its own visible number within the agency account. Agency pricing · Agency details.
FAQ
Can I require SMS for every message?
The API accepts SMS as an optional service value, but the documented send result can select automatic routing for delivery safety. Test the specific recipient and inspect the result if your workflow requires SMS itself. API docs.
Can an unregistered person text the agent?
On the documented self-serve route, inbound messages from unregistered numbers are ignored. Register the recipient or follow the documented send-first route within your plan's limits. Phone-number reference.
Does a successful send mean the agent can handle replies?
No. A send acknowledgment or delivery status describes the outbound side. Keep the listener connected and verify that the matching inbound message reaches the agent. Delivery-status reference.