API Test Base is a free, offline-first tool for testing APIs and verifying not just their HTTP responses but their side effects, such as database records written, messages published to a queue, and downstream services called. It supports multiple protocols beyond HTTP, including IBM MQ, JMS, AMQP, MQTT, FTP/SFTP file triggers, and SOAP calls. Test cases are created with a no-code/low-code UI and can be run locally or automated in a CI/CD pipeline. It is built around a method called Integration Unit Testing, which treats an API as a black box tested against stub dependencies.
What it's for
Verify an API's HTTP response and its side effects (database writes, queue messages, downstream calls) in one test caseTest APIs triggered by queue messages (IBM MQ, JMS, AMQP, MQTT)Test APIs triggered by file drops on FTP or SFTP serversTest SOAP APIsAutomate integration unit tests in a CI/CD pipelineSet up test data (e.g. clear/insert database records) as part of a test caseStand up a dedicated stub database in a throwaway Docker container for test isolationData-driven testing with multiple data sets in a single test caseMock external services using HTTP stubs
Features 15
- Built around Integration Unit Testing method (black-box API testing with stub dependencies)
- Built-in test setup steps within a test case (e.g. database seed, HTTP call, database check)
- Can stand up a dedicated stub database (e.g. PostgreSQL) in a throwaway Docker container
- CI/CD pipeline automation of test suites
- Data-driven testing with multiple data sets
- Docker support for running the tool and stub dependencies
- Git-based team collaboration
- HTTP stubs (mock servers)
- No-code / low-code test case creation
- Offline-first, all data stored locally
- Pattern-based test case generation
- Standalone requests and structured test cases
- Structured test setup reusable across folders
- Supports multiple protocols: HTTP, IBM MQ, JMS, AMQP, MQTT, FTP, SFTP, SOAP
- Verifies API side effects (database, queue, downstream calls) alongside HTTP response
At a glance
free tier
TypeDesktop app
DeploymentInstalled (local)
PlatformsWindows, macOS, Linux
Integrations
JMSIBM MQDockerSFTPAMQPFTPSOAPPostgreSQLMQTTH2
Resources
Pricing
Product is free with no paid tiers available.
FreeFree
Described as a free, offline-first tool; no account or cloud required, run locally or in CI/CD.
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