How to migrate from SlickText to Telnyx

SlickText is a US and Canada SMS, MMS, and RCS marketing platform built around mass-texting campaigns, automation, and two-way conversations. Telnyx is a licensed telecom carrier that runs a CPaaS platform with APIs for SMS, MMS, RCS, WhatsApp, voice, and email over its own private global IP network. On the messaging.dev Score, SlickText rates 38/100 and Telnyx 78/100; this guide covers what actually changes when you move your sending code from one to the other.

What changes when you move

Channels. You gain WhatsApp, voice, and email. Both platforms already cover SMS, MMS, and RCS, so you lose no messaging channel by switching, and neither supports Viber, Telegram, Facebook Messenger, or Apple Messages for Business.

Compliance and data residency. Both carry SOC 2 and HIPAA. Telnyx additionally lists GDPR and ISO 27001, which SlickText does not. Residency is the larger shift: SlickText runs on US servers only with no region choice, while Telnyx offers both US and EU servers with customer-selectable data residency, plus Asia-Pacific and South America regions. Coverage widens from 2 countries to 130.

Pricing. The billing model changes shape. SlickText sells monthly subscription plans with a fixed pool of message credits (one credit equals one SMS segment), starting at $29/month for 500 credits (~$0.058 per credit) with rollover. Telnyx is pay-as-you-go, billed per message part at $0.004 per outbound US SMS part plus carrier fees. Neither offers a free developer credit.

Tooling and docs. SlickText ships no official SDKs; Telnyx provides Node.js, Python, Ruby, Go, Java, .NET, and PHP. Docs quality rises from medium to high, and Telnyx exposes SMPP alongside REST. Neither provider offers a sandbox. Identical dimensions: both support self-onboarding and both are US-headquartered private companies.

How the request format differs

SlickText:

curl -X POST https://dev.slicktext.com/v1/brands/BRAND_ID/campaigns/ \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Send From API",
    "body": "Welcome to ACME",
    "status": "send",
    "audience": { "contact_lists": [21] }
  }'

Telnyx:

curl -X POST https://api.telnyx.com/v2/messages \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "from": "+15551234567",
    "to": "+15559876543",
    "text": "Hello, world!"
  }'

Endpoint. You move from a brand-scoped campaign resource (https://dev.slicktext.com/v1/brands/{brand_id}/campaigns/) to a flat messages resource (https://api.telnyx.com/v2/messages). There is no brand ID in the Telnyx path.

Authentication. Both use a Bearer token in the Authorization header, so the mechanism is unchanged. Swap the SlickText token (generated under Settings > API & Webhooks > API Keys) for a Telnyx API key from its dashboard.

Payload mapping. The recipient changes from an audience of saved contact lists (audience.contact_lists: [21]) to a single E.164 number in to. The sender is implicit on SlickText (tied to the brand), whereas Telnyx requires an explicit from number you provision. Rename body to text, and drop SlickText’s name and status fields, which have no Telnyx equivalent. In short, you move from list-based campaign sends to per-recipient messages.

Migration checklist

1. Create a Telnyx account, provision a sending phone number, and generate an API key. See how to start with Telnyx for the walkthrough.
2. Map the request fields: body → text, audience.contact_lists → to (one E.164 number per message), add an explicit from, and drop name/status.
3. Re-point your sending code to https://api.telnyx.com/v2/messages and swap in the Telnyx Bearer key.
4. Re-test. Telnyx has no sandbox, so send live to a test number you control using a low-volume key.
5. Update webhooks and delivery callbacks to Telnyx’s event format and re-register your callback URLs.
6. Run both providers in parallel, mirroring a share of traffic to Telnyx to compare delivery.
7. Cut over once delivery and reporting match, then decommission the SlickText path.

Watch out for

• No sandbox. Neither provider offers an isolated test environment, so all testing happens against live numbers and live billing.
• Carrier fees and no free credit. The $0.004 US SMS part price is before carrier fees, and there is no free developer credit, so you pay from the first message.
• Billing model shift. You move from prepaid subscription credit pools with rollover to metered pay-as-you-go per message part; budget and rate-limit accordingly.
• List vs. number sends. SlickText resolves recipients from saved contact lists; Telnyx sends to one number per request, so recipient management moves into your own code.

For a full side-by-side, see the SlickText vs. Telnyx comparison.