Stubborn Contract

5.7easy start · #20 of 22
in Contract Testing Tools

Free to practise onnot on record
Free trialnot on record
Well documentednot on record
Runs where you worknot on record

Runs on api, self-hosted.

Stubborn Contract is ranked #20 of 22 in contract testing tools on The Geeks Club. It runs on API, Self-hosted. There is a free plan.

Stubborn Contract plans and pricing

All plans

Open-source core Free Contract-testing core and Stubborn Broker OSS · free to use, modify, and deploy under Apache 2.0 stubborn.sh · 5 Oct 2026

Enterprise Partnership Not published Scoped to the organization’s needs; no public pricing Stubborn Pro capabilities · migration planning · architecture sessions · priority engineering · direct maintainer communication · custom integrations stubborn.sh · 5 Oct 2026

Compared on contract testing tools

Free plan: Yes
Contract formats: YAML, Groovy, Java, Kotlin
Consumer verification: Yes
Provider verification: Yes
Contract registry: Yes
Self-hosted deployment: Yes

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The record

Purpose: Stubborn Contract is the official continuation of Spring Cloud Contract, providing consumer-driven contract testing for HTTP and message-based interactions.
Open-source license: The contract-testing core and Stubborn Broker OSS are licensed under Apache 2.0 and are free to use, modify, and deploy.
HTTP and messaging: The testing project supports contracts for both HTTP and message-based interactions.
Supported formats: Existing Groovy DSL, YAML, and Java DSL contracts continue to work during migration.
Broker governance: Stubborn Broker verifies contracts across branches and services and provides a CI-friendly can-i-deploy check.
Broker features: The Broker page lists branch-aware governance, AI contract generation from captured HTTP traffic, and AI-agent integration through MCP.
Languages: The Broker page lists Java, Kotlin, JavaScript, and TypeScript SDK support.
Messaging integrations: Stubborn Contract 0.1.2 adds Spring-free messaging building blocks for Kafka, RabbitMQ, and JMS.
Build integrations: Contracts can be published through Maven or Gradle plugins, or through the CLI.
Self-hosting: The Broker page provides a Docker command to run the server locally on port 8080.
Runtime requirement: Stubborn Contract 0.1.2 runs on Java 17 or later and is listed as tested with Java 21 and 25 and Spring Boot 4.1.
Migration: The migration guide says an OpenRewrite recipe automates mechanical migration steps from Spring Cloud Contract.
Community support: Community support is best effort through GitHub issues, with no public SLA for free support.
Enterprise support: Enterprise Partnerships include direct maintainer communication and support for integrating the project into an organization’s CI/CD and deployment pipelines.
Price from: Free

Where it ranks on The Geeks Club

Best Contract Testing Tools in 2026#20 of 22

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Sources

github.com/stubborn-sh/stubborn-contract· checked 5 Oct 2026
stubborn.sh/governance/· checked 5 Oct 2026
stubborn.sh/transition-guide/· checked 5 Oct 2026
stubborn.sh/broker/· checked 5 Oct 2026
stubborn.sh/enterprise/· checked 5 Oct 2026