GatewayAPI

Spec sheet

Product

GatewayAPI is a cloud communications platform for sending SMS, RCS and email messages.Read 20 Oct 2026 · gatewayapi.com

Free plan

NoRead 24 Sep 2026 · gatewayapi.com

Trial

New accounts enter a 30-day trial period with security-related restrictions until activation.Read 20 Oct 2026 · gatewayapi.com

Integrations

Supported integrations include WordPress, Kannel, SMPP, Make and Zapier.Read 20 Oct 2026 · gatewayapi.com

Security

GatewayAPI states that it receives annual ISAE 3000 and ISAE 3402 auditor statements concerning GDPR compliance.Read 20 Oct 2026 · gatewayapi.com

Support

The maker advertises average support response times below 20 seconds during working hours and a 98 percent satisfaction rate.Read 20 Oct 2026 · gatewayapi.com

License

GatewayAPI is a proprietary hosted service operated under ONLINECITY.IO terms; its published documents reserve software copyright to ONLINECITY.IO.Read 20 Oct 2026 · gatewayapi.com

Company

GatewayAPI is owned and operated by ONLINECITY.IO, which the company says has operated since 1999.Read 9 Oct 2026 · gatewayapi.com

Account controls

Security add-ons include country and rate limits, IP whitelisting, and URL whitelisting.Read 9 Oct 2026 · gatewayapi.com

API endpoint

Message API calls use messaging.gatewayapi.com or messaging.gatewayapi.eu, protected by automatically renewed certificates.Read 20 Oct 2026 · gatewayapi.com

API styles

Documentation covers a modern Message API, a legacy REST API, SMPP for selected customers and Email APIs.Read 20 Oct 2026 · gatewayapi.com

Availability

GatewayAPI reports historical average uptime above 99.99 percent.Read 20 Oct 2026 · gatewayapi.com

Code examples

Official examples cover C#, cURL, Go, HTTPie, Java, Node.js, PHP, Python and Ruby.Read 20 Oct 2026 · gatewayapi.com

Company founding

ONLINECITY.IO began in 1999 as a project founded by Thomas Hofmann and Ulrik Hoffmann.Read 20 Oct 2026 · onlinecity.io

Company ownership

GatewayAPI is owned and operated by Danish company ONLINECITY.IO ApS.Read 20 Oct 2026 · onlinecity.io

Confidential messaging

The Secret feature excludes message content, sender, and recipient from the traffic log and system storage.Read 9 Oct 2026 · gatewayapi.com

Dashboard

The service includes a customer dashboard with traffic logs, delivery tracking and multi-account administration.Read 20 Oct 2026 · gatewayapi.com

Data retention

The EU data-processing agreement says personal information is retained for up to 30 days after SMS shipment or receipt.Read 20 Oct 2026 · onlinecity.io

Developer access

The documentation recommends its Message API for new customers sending SMS and RCS messages to phone numbers.Read 9 Oct 2026 · gatewayapi.com

Documentation depth

The documentation is searchable, example-rich, regularly reviewed and includes an OpenAPI specification for the Message API.Read 20 Oct 2026 · gatewayapi.com

Email limitation

Email messaging currently has no delivery reports, according to the help center.Read 20 Oct 2026 · gatewayapi.com

Email services

GatewayAPI provides REST email sending plus SMS-to-email and email-to-SMS services.Read 20 Oct 2026 · gatewayapi.com

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.Read 20 Oct 2026 · gatewayapi.com

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.Read 9 Oct 2026 · gatewayapi.com

EU hosting

An EU setup keeps hosting and ownership within the European Union for customers with regional data requirements.Read 20 Oct 2026 · gatewayapi.com

Free account

Creating and maintaining a GatewayAPI account does not cost anything, while SMS traffic is billed separately.Read 9 Oct 2026 · gatewayapi.com

Limit: dashboard

A G2 reviewer says the newer dashboard was still in beta and needed better filtering and analysis.Read 20 Oct 2026 · g2.com

Limit: documentation

One Software Advice reviewer wanted OpenAPI or Swagger documentation for the API.Read 20 Oct 2026 · softwareadvice.com

Limit: missing features

Software Advice reviews request additional capabilities such as audio messaging and more integrations.Read 20 Oct 2026 · softwareadvice.com

Limit: onboarding

G2 reviewers say regulatory checks and thorough onboarding can delay the start of service.Read 20 Oct 2026 · g2.com

Limit: scheduling

A Software Advice reviewer reported problems with SMS scheduling and delayed replies.Read 20 Oct 2026 · softwareadvice.com

Limit: URL approval

Several Trustpilot reviewers complain that legitimate business URLs, including WhatsApp links, were rejected or required unclear approval explanations.Read 20 Oct 2026 · uk.trustpilot.com

Messaging features

Its SMS services include virtual numbers, shortcodes, keywords, number lookup, and two-way messaging.Read 9 Oct 2026 · gatewayapi.com

Number lookup

The product toolbox includes an HLR Number Lookup API for number verification.Read 20 Oct 2026 · gatewayapi.com

Payment limits

Bank-transfer invoicing requires a minimum of 150 euros, while monthly invoicing costs 50 euros per invoice and requires credit assessment.Read 20 Oct 2026 · gatewayapi.com

Praise: delivery

Software Advice reviewers describe the gateway as reliable, fast and useful for high-volume communication.Read 20 Oct 2026 · softwareadvice.com

Praise: support

G2 reviewers repeatedly praise fast, direct and highly responsive customer support.Read 20 Oct 2026 · g2.com

Praise: Trustpilot support

Trustpilot reviewers praise quick, patient support, affordable usage-based pricing and easy API setup.Read 20 Oct 2026 · uk.trustpilot.com

Praise: usability

G2 reviewers describe setup and API integration as straightforward, with some reporting successful implementation within a day or minutes after onboarding.Read 20 Oct 2026 · g2.com

Praise: value

Software Advice reviewers repeatedly praise low SMS pricing, core functionality and value for money.Read 20 Oct 2026 · softwareadvice.com

Rating on G2

GatewayAPI scores 4.9 out of 5 from 10 reviews.Read 20 Oct 2026 · g2.com

Rating on Software Advice

GatewayAPI scores 4.9 out of 5 from 70 reviews.Read 20 Oct 2026 · softwareadvice.com

Rating on Trustpilot

GatewayAPI scores 4.0 out of 5 from 19 reviews.Read 20 Oct 2026 · uk.trustpilot.com

RCS

RCS Business Messaging supports interactive branded messages with rich media.Read 9 Oct 2026 · gatewayapi.com

RCS fallback

The Messaging API automatically falls back to SMS when a recipient cannot receive RCS.Read 20 Oct 2026 · gatewayapi.com

RCS messaging

RCS messages can include branded sender profiles, images, videos, carousels, buttons and suggested actions.Read 20 Oct 2026 · gatewayapi.com

SDK

GatewayAPI publishes a type-safe Node.js SDK installable as @onlinecity/gatewayapi-node.Read 20 Oct 2026 · gatewayapi.com

Security audits

GatewayAPI says it receives annual ISAE 3000 and ISAE 3402 auditor statements concerning GDPR compliance.Read 9 Oct 2026 · gatewayapi.com

SMPP access

A direct SMPP connection for high-volume SMS is available to selected customers.Read 9 Oct 2026 · gatewayapi.com

SMS gateway

Its messaging service routes SMS through telecommunications networks and supports global delivery.Read 20 Oct 2026 · gatewayapi.com

Transactional use

GatewayAPI describes transactional messaging for automated alerts, one-time passwords, and order updates.Read 9 Oct 2026 · gatewayapi.com

Two-way messaging

Virtual numbers, short codes and keywords support inbound and outbound SMS conversations.Read 20 Oct 2026 · gatewayapi.com

Plans and prices

Every GatewayAPI plan and price →

Where Specifiction places it

• SMS APIs#3 of 348.8
• Transactional SMS Software#9 of 768.7
• SMS API services#17 of 358.3