/telnyx-messaging-curl

name: telnyx-messaging-curl
description: >-
  Send and receive SMS/MMS, handle opt-outs and delivery webhooks. Use for
  notifications, 2FA, or messaging apps.
metadata:
  author: telnyx
  product: messaging
  language: curl
  generated_by: telnyx-openapi-pipeline
  contract: v2

<!-- Auto-generated from Telnyx OpenAPI specs. Do not edit. -->

Telnyx Messaging - curl

Installation

# curl is pre-installed on macOS, Linux, and Windows 10+

Setup

export TELNYX_API_KEY="YOUR_API_KEY_HERE"

All examples below use `$TELNYX_API_KEY` for authentication.

Error Handling

All API calls can fail with network errors, rate limits (429), validation errors (422), or authentication errors (401). Always handle errors in production code:

curl \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "to": "+13125550001",
      "from": "+18005550101",
      "text": "Hello from Telnyx!"
  }' \
  "https://api.telnyx.com/v2/messages"

Common error codes: `401` invalid API key, `403` insufficient permissions, `404` resource not found, `422` validation error (check field formats), `429` rate limited (retry with exponential backoff).

Important Notes

• **Phone numbers** must be in E.164 format (e.g., `+13125550001`). Include the `+` prefix and country code. No spaces, dashes, or parentheses.
• **Pagination:** List endpoints return paginated results. Use `page[number]` and `page[size]` query parameters to navigate pages. Check `meta.total_pages` in the response.

Operational Caveats

• The sending number must already be assigned to the correct messaging profile before you send traffic from it.
• US A2P long-code traffic must complete 10DLC registration before production sending or carriers will block or heavily filter messages.
• Delivery webhooks are asynchronous. Treat the send response as acceptance of the request, not final carrier delivery.

Reference Use Rules

Do not invent Telnyx parameters, enums, response fields, or webhook fields.

• If the parameter, enum, or response field you need is not shown inline in this skill, read [references/api-details.md](references/api-details.md) before writing code.
• Before using any operation in `## Additional Operations`, read [the optional-parameters section](references/api-details.md#optional-parameters) and [the response-schemas section](references/api-details.md#response-schemas).
• Before reading or matching webhook fields beyond the inline examples, read [the webhook payload reference](references/api-details.md#webhook-payload-fields).

Core Tasks

Send an SMS

Primary outbound messaging flow. Agents need exact request fields and delivery-related response fields.

`POST /messages`

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | `to` | string (E.164) | Yes | Receiving address (+E.164 formatted phone number or short co... | | `from` | string (E.164) | Yes | Sending address (+E.164 formatted phone number, alphanumeric... | | `text` | string | Yes | Message body (i.e., content) as a non-empty string. | | `messaging_profile_id` | string (UUID) | No | Unique identifier for a messaging profile. | | `media_urls` | array[string] | No | A list of media URLs. | | `webhook_url` | string (URL) | No | The URL where webhooks related to this message will be sent. | | ... | | | +7 optional params in [references/api-details.md](references/api-details.md) |

curl \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "to": "+13125550001",
      "from": "+18005550101",
      "text": "Hello from Telnyx!"
  }' \
  "https://api.telnyx.com/v2/messages"

Primary response fields:

• `.data.id`
• `.data.to`
• `.data.from`
• `.data.text`
• `.data.sent_at`
• `.data.errors`

Send an SMS with an alphanumeric sender ID

Common sender variant that requires different request shape.

`POST /messages/alphanumeric_sender_id`

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | `from` | string (E.164) | Yes | A valid alphanumeric sender ID on the user's account. | | `to` | string (E.164) | Yes | Receiving address (+E.164 formatted phone number or short co... | | `text` | string | Yes | The message body. | | `messaging_profile_id` | string (UUID) | Yes | The messaging profile ID to use. | | `webhook_url` | string (URL) | No | Callback URL for delivery status updates. | | `webhook_failover_url` | string (URL) | No | Failover callback URL for delivery status updates. | | `use_profile_webhooks` | boolean | No | If true, use the messaging profile's webhook settings. |

curl \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "from": "MyCompany",
  "to": "+13125550001",
  "text": "Hello from Telnyx!",
  "messaging_profile_id": "550e8400-e29b-41d4-a716-446655440000"
}' \
  "https://api.telnyx.com/v2/messages/alphanumeric_sender_id"

Primary response fields:

• `.data.id`
• `.data.to`
• `.data.from`
• `.data.text`
• `.data.sent_at`
• `.data.errors`

---

Webhook Verification

Telnyx signs webhooks with Ed25519. Each request includes `telnyx-signature-ed25519` and `telnyx-timestamp` headers. Always verify signatures in production:

# Telnyx signs webhooks with Ed25519 (asymmetric — NOT HMAC/Standard Webhooks).
# Headers sent with each webhook:
#   telnyx-signature-ed25519: base64-encoded Ed25519 signature
#   telnyx-timestamp: Unix timestamp (reject if >5 minutes old for replay protection)
#
# Get your public key from: Telnyx Portal > Account Settings > Keys & Credentials
# Use the Telnyx SDK in your language for verification (client.webhooks.unwrap).
# Your endpoint MUST return 2xx within 2 seconds or Telnyx will retry (up to 3 attempts).
# Configure a failover URL in Telnyx Portal for additional reliability.

Webhooks

These web