Telnyx API
Browse all Telnyx APIs✓ Official Vendor SpecCommunicationsVoice Telephonybearer713 EndpointsREST
For Agents
Send SMS/MMS, control voice calls, manage phone numbers, and run AI assistants on calls through a single API with 713 endpoints covering telephony, messaging, and AI inference.
Use for: I need to send an SMS message through Telnyx, I want to initiate a voice call and play a greeting, Search for available phone numbers in a specific area code, Start an AI assistant on an active call for transcription
Not supported: Does not handle email delivery, push notifications, or notification orchestration — use for telephony, SMS, fax, SIP, and embedded AI only.
Deliver SMS, MMS, voice calls, fax, SIP trunking, and AI-powered call control through a unified API with 713 endpoints. Purchase and manage phone numbers across 60+ countries, configure messaging profiles and campaigns for 10DLC compliance, and run AI assistants on live calls. Includes embedded AI features for chat completions, embeddings, transcription, and fine-tuning alongside core telephony services.
Install Jentic One Beta
Connect the Telnyx API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Telnyx 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://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | 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 Telnyx API.
Send SMS, MMS, and group messages through long codes, short codes, and number pools with delivery tracking
Control active voice calls with answer, hangup, transfer, gather DTMF, record, and text-to-speech commands
Purchase and configure phone numbers across 60+ countries with instant activation
Run AI assistants on live calls for conversational IVR, transcription, and intelligent call routing
Send and receive faxes programmatically with status tracking and media retrieval
Configure SIP trunking with credential and IP-based authentication for enterprise voice
Generate text embeddings, run chat completions, and fine-tune models through integrated AI endpoints
Use Cases
Patterns agents use Telnyx API for, with concrete tasks.
★ AI Agent Communications Automation
AI agents send messages and control calls through Jentic by searching for Telnyx operations, loading schemas, and executing with bearer token injection. Jentic handles authentication from the MAXsystem vault so agents operate across SMS, voice, and AI endpoints without managing API keys. A single API surface covers messaging, call control, number management, and AI inference.
Send an SMS from +15551234567 to +15559876543 with text 'Your appointment is confirmed' via POST /messages and verify the message_id is returned
Programmable Voice with AI Assistants
Build intelligent call flows by combining Telnyx call control commands with embedded AI assistants. Start a call, then attach an AI assistant for real-time transcription, conversational IVR, or AI-powered information gathering. The assistant handles natural language interaction while the call control API manages hold, transfer, and recording — all through a single platform without external AI service integrations.
Initiate a call via POST /calls, then start an AI assistant on the call via POST /calls/{call_control_id}/actions/ai_assistant_start with a greeting prompt
10DLC Messaging Compliance
Register brands and campaigns for US 10DLC messaging compliance through the API. Create messaging profiles that associate phone numbers with registered campaigns, ensuring messages are delivered with carrier trust scores. The API handles brand registration, campaign submission, and number assignment — covering the full compliance lifecycle without manual carrier portals.
Create a messaging profile via the API, register a brand, submit a campaign for approval, and assign a phone number to the messaging profile
Multi-Channel Number Management
Search, purchase, and configure phone numbers for voice, SMS, MMS, and fax across 60+ countries. Filter available numbers by area code, features, and number type. Configure purchased numbers with connection assignments, messaging profiles, and emergency addresses. Supports number porting, block purchases, and sub-organization number allocation.
Search available US phone numbers with SMS capability via GET /available_phone_numbers with filter[features]=sms and purchase the first result
Key Endpoints
713 endpoints — deliver sms, mms, voice calls, fax, sip trunking, and ai-powered call control through a unified api with 713 endpoints.
METHOD
PATH
DESCRIPTION
POST
/messages
Send an SMS or MMS message
GET
/messages/{id}
Retrieve message details and delivery status
POST
/calls
Initiate an outbound voice call
POST
/calls/{call_control_id}/actions/answer
Answer an incoming call
POST
/calls/{call_control_id}/actions/ai_assistant_start
Start an AI assistant on an active call
GET
/available_phone_numbers
Search available phone numbers for purchase
POST
/faxes
Send a fax
POST
/ai/chat/completions
Run AI chat completions
POST
/messages
Send an SMS or MMS message
GET
/messages/{id}
Retrieve message details and delivery status
POST
/calls
Initiate an outbound voice call
POST
/calls/{call_control_id}/actions/answer
Answer an incoming call
POST
/calls/{call_control_id}/actions/ai_assistant_start
Start an AI assistant on an active call
GET
/available_phone_numbers
Search available phone numbers for purchase
POST
/faxes
Send a fax
POST
/ai/chat/completions
Run AI chat completions
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
Telnyx bearer tokens are stored encrypted in the Jentic vault (MAXsystem). Agents receive pre-authenticated requests — raw API keys never enter the agent context or appear in logs.
Intent-based discovery
Agents search by intent (e.g., 'send an SMS message' or 'start AI assistant on a call') and Jentic returns matching Telnyx operations from 713 endpoints with input schemas, so the agent finds the right operation without navigating the full API surface.
Time to first call
Direct Telnyx integration: 3-5 days for auth setup, number provisioning, messaging profile configuration, and call control webhooks. Through Jentic: under 1 hour — search, load schema, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Telnyx API through Jentic.
What authentication does the Telnyx API use?
The Telnyx API uses Bearer token authentication. Include your API key in the Authorization header as 'Bearer YOUR_API_KEY'. Through Jentic, your Telnyx bearer token is stored encrypted in the MAXsystem vault and injected automatically into requests, so agents never handle the raw API key.
Can I run AI assistants on live voice calls with Telnyx?
Yes. After initiating or answering a call, POST to /calls/{call_control_id}/actions/ai_assistant_start with a system prompt and configuration. The AI assistant handles conversational interaction on the call in real-time. Stop it with /actions/ai_assistant_stop when complete.
What are the rate limits for the Telnyx messaging API?
Telnyx messaging rate limits depend on your number type and messaging profile. Long codes support 1 message per second per number. Toll-free numbers support higher throughput after verification. Short codes support 30+ messages per second. The API returns 429 when limits are exceeded.
How do I send an SMS through Jentic with the Telnyx API?
Search for 'send an SMS message' in Jentic to find the Telnyx messages endpoint. Load the operation schema, then execute with from (your Telnyx number), to (recipient), and text (message body). Install with pip install jentic and use the search-load-execute flow. Jentic injects the bearer token automatically. Get started at https://app.jentic.com/sign-up.
Does Telnyx support 10DLC messaging compliance?
Yes. Telnyx provides API endpoints for brand registration, campaign submission, and number-to-campaign assignment. Create a messaging profile, register your brand, submit a campaign for carrier approval, and assign numbers to the profile. The API covers the full 10DLC compliance lifecycle.
Can I send faxes through the Telnyx API?
Yes. POST to /faxes with the to number, from number, and media URL of the document to fax. The API returns a fax ID for status tracking. Retrieve fax status and received faxes via GET /faxes/{id}. Supports PDF and TIFF formats.
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