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Telnyx Messaging — Documentation Index

SMS, MMS, RCS, WhatsApp, short codes, 10DLC compliance, and messaging profiles. One section of the Telnyx developer docs (https://developers.telnyx.com). Root index: https://developers.telnyx.com/llms.txt · Full content for this section: https://developers.telnyx.com/development/llms/messaging-llms-full-txt.md

Subsections

Focused per-subsection files (index + full content):

SMS & MMS

  • Send Your First Message: Send your first SMS in five minutes using the Telnyx Messaging API, including authentication, picking a sender, and posting a message to the /messages endpoint.
  • Receive Messages: Receive inbound SMS and MMS messages via webhooks using the Telnyx Messaging API — with auto-reply, MMS media handling, and webhook signature verification.
  • Webhooks: Receive, verify, and handle Telnyx messaging webhooks. Covers all event types, signature verification, retry behavior, and SDK code examples.
  • Choosing a Sender Type: Compare long codes, toll-free, short codes, RCS, and alphanumeric sender IDs to find the best messaging channel for your business.
  • Message Encoding: Understand SMS encoding types, character limits, segment calculations, and how to optimize message length to reduce costs.
  • Rate Limiting: Understand Telnyx SMS and MMS delivery rate limits by sender type — long code, toll-free, short code, 10DLC — and how to optimize message throughput.
  • Error Codes: Complete reference of Telnyx Messaging API error codes with descriptions, causes, and recommended actions.
  • Smart Encoding: Automatically substitute Unicode characters with GSM-7 equivalents to reduce SMS segment counts and costs.
  • Group Messaging: Send and receive group MMS messages to multiple recipients using the Telnyx Messaging API. Supports up to 8 participants per conversation.
  • Alphanumeric Sender ID: Send branded SMS messages using custom alphanumeric sender IDs instead of phone numbers.
  • International Compliance: Country-specific SMS registration requirements, sender ID rules, opt-in regulations, and content restrictions for the top international messaging destinations.
  • MMS Converter: |
  • MMS Media & Transcoding: Send MMS messages with media attachments. Understand carrier size limits, supported formats, and automatic transcoding.
  • Schedule Messages: Schedule SMS and MMS messages for future delivery on Telnyx. Send time-sensitive campaigns, reminders, and notifications at exactly the right moment.
  • Specifying SMIL Template: Customize the SMIL template used by Telnyx MMS to control how images, video, and text are laid out and rendered on recipient devices for picture messages.
  • Two-Factor Authentication (2FA): Implement SMS-based two-factor authentication with the Telnyx Messaging API. Includes OTP generation, delivery, verification, and security best practices.
  • Appointment Reminders: Send automated appointment reminders with the Telnyx Messaging API. Includes scheduling strategies, opt-out handling, and best practices.
  • Send & Receive MMS: Send MMS messages with media attachments and handle inbound MMS webhooks with code examples in 7 languages.
  • Zapier Integration: Connect Telnyx SMS to 7,000+ apps with Zapier. Automate messaging workflows without code — send alerts, forward messages, and create auto-responders.
  • Vercel Chat SDK: Build bots in Next.js that send and receive SMS and MMS through Telnyx using the official @telnyx/chat-sdk-adapter package for Vercel’s Chat SDK.
  • Spend Limits: Set daily spending limits on messaging profiles to prevent unexpected costs. Handle limit-reached webhooks and manage overrides.
  • Message Detail Records: Track message status and delivery with Message Detail Records (MDRs).
  • Overview: Understand Telnyx messaging profiles — the central configuration for your messaging numbers, webhooks, features, and spend limits.
  • Number Pool: Distribute outbound messaging across multiple phone numbers to maximize deliverability and throughput.
  • Sticky Sender: Maintain consistent sender numbers for recipients across messages to build familiarity and trust.
  • Geomatch: Automatically select sender numbers that match recipient area codes for higher engagement and trust.
  • Short Codes: Request and configure short codes for high-volume A2P messaging. Understand provisioning timelines, carrier certification, and use cases.
  • Hosted SMS: Use Hosted SMS on Telnyx to enable SMS/MMS on a phone number that stays with your voice provider. Includes eligibility checks, verification, and orders.
  • Internal Transfer: Transfer hosted SMS numbers between Telnyx accounts. Learn how
  • Opt-In/Out Management: Configure custom opt-in and opt-out keywords, auto-responses, and country-specific messaging to maintain CTIA & TCPA compliance.
  • Number Configuration: Configure phone numbers for messaging — assign to messaging profiles, enable messaging features, manage number settings, and troubleshoot common issues.
  • Toll-Free Verification: New Business Registration Number (BRN) fields for toll-free SMS/MMS verification, including mandatory requirements starting February 2026.
  • Troubleshooting: Diagnose and resolve toll-free verification rejections, resubmission issues, delivery problems, and throughput limitations for SMS/MMS on toll-free numbers.
  • Quickstart: Register your brand and campaign for 10DLC A2P messaging. Complete guide with Portal walkthrough and API/SDK examples.
  • Sole Proprietor: Complete guide to registering Sole Proprietor brands and campaigns via the Telnyx API, including OTP verification flow.
  • Brand Registration: Complete guide to registering your business as a 10DLC brand with Telnyx, including entity types, vetting scores, rejection troubleshooting, and SDK examples.
  • Campaign Registration: Register your 10DLC campaign with TCR, choose the right use case type, write sample messages that pass carrier review, and handle rejections programmatically.
  • Use Case Examples: Compliant sample messages, opt-in language, and content patterns for every 10DLC campaign use case type — ready to use in your TCR registration.
  • ISV/Reseller Onboarding: Register 10DLC brands and campaigns on behalf of your customers using Telnyx partner campaign APIs. Complete guide for ISVs, resellers, and SaaS platforms.
  • Rate Limits & Scores: Understand AT&T and T-Mobile 10DLC rate limits by vetting score, campaign type, and carrier. Optimize your brand score for higher throughput.
  • Phone Number Assignment: Assign phone numbers to 10DLC campaigns, manage bulk assignments, integrate with number pools, and troubleshoot common assignment failures.
  • Event Notifications: Configure webhooks to receive real-time notifications about 10DLC brand registrations, campaign status changes, and phone number assignments.
  • Troubleshooting: Diagnose and resolve common 10DLC brand registration, campaign approval, phone number assignment, and messaging delivery issues.

RCS

  • RCS Getting Started: Get started with Rich Communication Services (RCS) messaging on Telnyx, including agent registration, sending rich cards, suggested actions, and media.
  • RCS with AI Assistant: Build an intelligent RCS agent powered by Telnyx AI Assistant—no custom backend required.
  • Send RCS Messages: Send rich RCS messages with text, rich cards, carousels, and suggested actions using the Telnyx RCS API. Includes SDK examples and SMS fallback.
  • Capabilities & Deeplinks: Query device RCS capabilities before sending and generate deeplinks to start RCS conversations from websites or QR codes.
  • RCS Deeplinks: Generate RCS deeplinks to start conversations from websites, QR codes, and email campaigns.
  • RCS Webhooks: Receive RCS webhooks from Telnyx — delivery receipts, inbound messages, read receipts, suggestion responses — with payload structure and SDK examples.

WhatsApp

  • Quickstart: Complete end-to-end guide to send your first WhatsApp message via Telnyx API, from setup to delivery confirmation.
  • Embedded Signup: Complete the WhatsApp Business Platform embedded signup flow in the Telnyx portal. Create your WABA and register phone numbers for WhatsApp messaging.
  • Tech Provider Embedded Signup: Enable your end-customers to self-serve onboard WhatsApp Business Accounts through your platform using Meta’s embedded signup flow integrated with Telnyx.
  • Send Messages: Send template, text, media, interactive, and location messages via the Telnyx WhatsApp API.
  • Manage Templates: Create, list, update, and delete WhatsApp message templates via the Telnyx API. Includes template structure, category selection, and lifecycle management.

API Reference (Messaging)

Messages

Whatsapp messaging

Callbacks

Profiles

Opt-Out Management

Messaging

Short Codes

Hosted Numbers

Number Settings

Verification Requests

Campaign

Brands

  • List Brands: This endpoint is used to list all brands associated with your organization.
  • Create Brand: This endpoint is used to create a new brand. A brand is an entity created by The Campaign Registry (TCR) that represents an organization or a company. It is th…
  • Get Brand: Retrieve a brand by brandId.
  • Update Brand: Update a brand’s attributes by brandId.
  • Delete Brand: Delete Brand. This endpoint is used to delete a brand. Note the brand cannot be deleted if it contains one or more active campaigns, the campaigns need to be i…
  • Resend brand 2FA email
  • List External Vettings: Get list of valid external vetting record for a given brand
  • Order Brand External Vetting: Order new external vetting for a brand.
  • Import External Vetting Record: This operation can be used to import an external vetting record from a TCR-approved
  • Revet Brand: This operation allows you to revet the brand. However, revetting is allowed once after the successful brand registration and thereafter limited to once every 3…
  • Get Brand SMS OTP Status by Brand ID: Query the status of an SMS OTP (One-Time Password) for Sole Proprietor brand verification using the Brand ID.
  • Trigger Brand SMS OTP: Trigger or re-trigger an SMS OTP (One-Time Password) for Sole Proprietor brand verification.
  • Verify Brand SMS OTP: Verify the SMS OTP (One-Time Password) for Sole Proprietor brand verification.
  • Get Brand SMS OTP Status: Query the status of an SMS OTP (One-Time Password) for Sole Proprietor brand verification.
  • Get Brand Feedback By Id: Get feedback about a brand by ID. This endpoint can be used after creating or revetting

Enum

Shared Campaigns

Phone Number Campaigns

Bulk Phone Number Campaigns

  • Assign Messaging Profile To Campaign: This endpoint allows you to link all phone numbers associated with a Messaging Profile to a campaign. Please note: if you want to assign phone numbers to a…
  • Get Assignment Task Status: Check the status of the task associated with assigning all phone numbers on a messaging profile to a campaign by taskId.
  • Get Phone Number Status: Check the status of the individual phone number/campaign assignments associated with the supplied taskId.

RCS

Whatsapp Business Accounts

Whatsapp Phone Numbers

Whatsapp Message Templates