Freedom251 › Transactional SMS Software
GatewayAPI
What GatewayAPI is
GatewayAPI is a paid messaging platform for sending SMS, RCS, and email through web tools and APIs. SMS capabilities include virtual numbers, shortcodes, keywords, number lookup, two-way messaging, inbound webhooks, and MMS. RCS Business Messaging supports interactive branded messages with rich media. Transactional messaging can deliver alerts, one-time passwords, and order updates. The Message API is recommended for new SMS and RCS projects, while selected high-volume customers can use direct SMPP connections. Creating and maintaining an account is free, but SMS traffic is billed separately. Pay-as-you-go SMS has no monthly subscription by default, with country-specific rates and possible short-code requirements. RCS Basic is listed at €0.04, paid once per RCS message per operator in the selected country, with the shown price for HI3G. Integrations include WordPress, Zapier, Make, Shopify, WooCommerce, Salesforce, Slack, and Zendesk. EU hosting, Secret messaging, rate limits, IP and URL allowlists, and annual GDPR-related auditor statements are documented.
Who it suits
GatewayAPI suits businesses sending transactional or conversational messages through APIs, web tools, or listed integrations. It also fits teams needing RCS, two-way SMS, webhooks, or EU data handling.
What it does well
- Free account creation and maintenance
- Supports SMS, RCS, and email
- Two-way SMS, MMS, and shortcodes
- Includes WordPress, Shopify, and Salesforce integrations
- EU data residency setup available
What to know first
- SMS traffic is billed separately
- RCS pricing varies by operator and country
- SMPP access limited to selected customers
- No monthly subscription by default for pay-as-you-go SMS
Limits
The account itself is free, but SMS traffic is billed separately. Pay-as-you-go SMS uses country-specific rates, and some destinations require a short code; RCS Basic pricing varies by operator and country.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| RCS Basic | Per RCS message/operator country · Price shown for HI3G operator · premium support available separately | €0.04, paid once |
| Pay-as-you-go SMS | Per message sent; no setup fee or default monthly subscription · Prices vary by country · virtual numbers may add monthly fees | On request |
As gatewayapi.com lists them, read 20 Oct 2026. The maker's own page has the final word.
Getting started
- Open the GatewayAPI website
- Create a free GatewayAPI account
- Use the Message API for SMS or RCS phone messaging
- Connect an integration such as Shopify, Zapier or Salesforce
- Configure webhooks, sender options and security controls
- Send traffic under the applicable country and operator rates
Verdict
GatewayAPI offers a broad messaging mix with developer APIs, integrations, and account security controls. Costs depend on traffic and country, so teams should check applicable rates and channel requirements.
Questions
Does GatewayAPI have a free plan?
Creating and maintaining an account is free. SMS traffic is billed separately.
What platforms does GatewayAPI support?
It is available through API and web interfaces, with Node.js listed for SDK development.
What does RCS Basic cost?
RCS Basic is listed at €0.04, paid once, billed per RCS message and operator in the selected country. The displayed price is for HI3G.
Can GatewayAPI send two-way messages?
Yes. Two-way SMS, inbound webhooks and MMS are supported.
Which integrations are listed?
Integrations include WordPress, Zapier, Make, Shopify, WooCommerce, Salesforce, Slack and Zendesk.
Who operates GatewayAPI?
GatewayAPI is owned and operated by ONLINECITY.IO.
Facts from GatewayAPI's own pages
- Account controls
- Security add-ons include country and rate limits, IP whitelisting, and URL whitelisting. · gatewayapi.com, 9 Oct 2026
- API endpoint
- Message API calls use messaging.gatewayapi.com or messaging.gatewayapi.eu, protected by automatically renewed certificates. · gatewayapi.com, 20 Oct 2026
- API styles
- Documentation covers a modern Message API, a legacy REST API, SMPP for selected customers and Email APIs. · gatewayapi.com, 20 Oct 2026
- Availability
- GatewayAPI reports historical average uptime above 99.99 percent. · gatewayapi.com, 20 Oct 2026
- Code examples
- Official examples cover C#, cURL, Go, HTTPie, Java, Node.js, PHP, Python and Ruby. · gatewayapi.com, 20 Oct 2026
- Company
- GatewayAPI is owned and operated by ONLINECITY.IO, which the company says has operated since 1999. · gatewayapi.com, 9 Oct 2026
- Company founding
- ONLINECITY.IO began in 1999 as a project founded by Thomas Hofmann and Ulrik Hoffmann. · onlinecity.io, 20 Oct 2026
- Company ownership
- GatewayAPI is owned and operated by Danish company ONLINECITY.IO ApS. · onlinecity.io, 20 Oct 2026
- Confidential messaging
- The Secret feature excludes message content, sender, and recipient from the traffic log and system storage. · gatewayapi.com, 9 Oct 2026
- Dashboard
- The service includes a customer dashboard with traffic logs, delivery tracking and multi-account administration. · gatewayapi.com, 20 Oct 2026
- Data retention
- The EU data-processing agreement says personal information is retained for up to 30 days after SMS shipment or receipt. · onlinecity.io, 20 Oct 2026
- Developer access
- The documentation recommends its Message API for new customers sending SMS and RCS messages to phone numbers. · gatewayapi.com, 9 Oct 2026
- Documentation depth
- The documentation is searchable, example-rich, regularly reviewed and includes an OpenAPI specification for the Message API. · gatewayapi.com, 20 Oct 2026
- Email limitation
- Email messaging currently has no delivery reports, according to the help center. · gatewayapi.com, 20 Oct 2026
- Email services
- GatewayAPI provides REST email sending plus SMS-to-email and email-to-SMS services. · gatewayapi.com, 20 Oct 2026
- Email-to-SMS limitation
- Email-to-SMS is intended for low-volume one-to-one use rather than large bulk campaigns and limits messages to 20 SMS parts. · gatewayapi.com, 20 Oct 2026
- EU data residency
- Its EU setup keeps data storage with a cloud provider operating physically in the EU and owned by an EU company, with connections handled through EU telecommunications companies and A2P providers by default. · gatewayapi.com, 9 Oct 2026
- EU hosting
- An EU setup keeps hosting and ownership within the European Union for customers with regional data requirements. · gatewayapi.com, 20 Oct 2026
- Free account
- Creating and maintaining a GatewayAPI account does not cost anything, while SMS traffic is billed separately. · gatewayapi.com, 9 Oct 2026
- Free plan
- No · gatewayapi.com, 24 Sept 2026
- Integrations
- Supported integrations include WordPress, Kannel, SMPP, Make and Zapier. · gatewayapi.com, 20 Oct 2026
- License
- GatewayAPI is a proprietary hosted service operated under ONLINECITY.IO terms; its published documents reserve software copyright to ONLINECITY.IO. · gatewayapi.com, 20 Oct 2026
- Limit: dashboard
- A G2 reviewer says the newer dashboard was still in beta and needed better filtering and analysis. · g2.com, 20 Oct 2026
- Limit: documentation
- One Software Advice reviewer wanted OpenAPI or Swagger documentation for the API. · softwareadvice.com, 20 Oct 2026
Where GatewayAPI stands on Freedom251
- Transactional SMS Software#29 of 76
- SMS APIs#16 of 34
- SMS API services#27 of 35