Enterprise-scale unit test generation. No babysitting.
AI coding agents have transformed how developers write code. But project-scale test generation is a fundamentally different kind of problem: long-running, multi-step, and demanding near-perfect output across thousands of files.
Works with your existing platform:
GitHub Copilot
Claude Code
Gemini CLI — Coming soon
Codex — Coming soon
THE PROBLEM
AI coding agents are incredible. Until you ask them to test an entire codebase.
AI coding agents have transformed how developers write code. But project-scale test generation is a fundamentally different kind of problem — long-running, multi-step, and demanding near-perfect output across thousands of files.
The ceiling problem
Even with a senior developer and the best AI agent, coverage tops out below 50%. Our benchmark across 8 repos averaged just 32%. The more you prompt, the less you get back — diminishing returns kick in fast.
The babysitting tax
Using AI agents for broad test generation requires constant context switching: monitoring output, re-prompting failures, fixing broken tests. This is the new form of developer toil: productivity gains eaten by agent supervision.
Millions of lines, no coverage
Millions of legacy lines at near-zero coverage. No developer can audit this manually. No chat-based agent can sustain the workflow. Your modernization depends on solving the test debt, and your AI agent wasn’t built for this.
AI coding agents are designed for flexibility. Enterprise-scale test generation requires orchestration, verification, and autonomy. That’s what the Diffblue Testing Agent provides.
HOW IT WORKS
Two ways to work. Same expertise.
Point it at your codebase. Walk away. Come back to comprehensive coverage.
The Diffblue Testing Agent CLI orchestrates your AI coding agent to execute a comprehensive process: coverage analysis, test plan creation, parallelized test generation, output verification, project clean-up, and PR preparation. It runs autonomously without developer intervention.
Processes hundreds of classes across multiple modules in a single run
Verifies every test: compiles, passes, and improves coverage before commit
Git worktree isolation — never touches your working branch
Verifies every test: compiles, passes, and improves coverage before commit
Generate tests inside your existing workflow.
Diffblue Agents installs directly into your Copilot or Claude Code workflow. Generate tests for the class you’re working on with the same enterprise verification, right inside your IDE.
Works inside Copilot and Claude Code
Same verification guarantees as batch mode
Generate tests for individual classes or methods
Immediate feedback in your development flow
WHY DIFFBLUE TESTING AGENT
What your AI platform can't do alone
Diffblue Testing Agent vs. AI coding agents alone — measured on real enterprise codebases.
Runs on your entire codebase. Without babysitting.
Point the Diffblue Testing Agent at a repository with hundreds of classes across multiple modules. It scopes the work, sequences execution, handles build failures, and rolls back cleanly — all without human intervention.
Every test compiles, passes, and improves coverage. Every time.
Our verification framework catches bad outputs before they touch your codebase. No flaky tests. No tests that fail on the next build. Every test is compiled, executed, and validated before it’s committed.
Proven workflows built by test engineers. Not prompt engineering.
A decade of formal methods, symbolic execution, and enterprise test automation — distilled into autonomous workflows. This isn’t a chatbot writing tests. It’s the world’s deepest testing expertise, automated.
BENCHMARK RESULTS
Don't take our word for it. See the data.
We challenged a senior developer armed with Claude Code to generate as much test coverage as possible across 8 Java repositories. Then we ran the Diffblue Testing Agent on the same repos. Autonomously.
You can't modernize safely without tests
Every Java 8 to 21 migration, every framework upgrade, every monolith decomposition hits the same wall: millions of lines with no test coverage. You can’t refactor what you can’t verify. Manual test writing would take years. Your modernization timeline doesn’t have years.
Diffblue Agents builds the safety net first — verified unit tests across your legacy codebase — so your team can modernize with confidence, not hope.
PLATFORM SUPPORT
Works with the platform you've already invested in
Diffblue Agents for GitHub Copilot
Enterprise test generation that makes your Copilot investment pay off
Diffblue Agents for Claude Code
Autonomous test generation with the reliability Claude alone can't deliver
Java 8, 11, 17, 21, 25
Python
Gemini CLI— Coming soon
Codex— Coming soon
ENTERPRISE TRUST
Built for organizations that can't afford to get testing wrong
Lines tested in production
Years of dev time saved
In production since
Production outages saved
Banks need months of security review. Defense contractors require air-gapped solutions. Healthcare companies need audit trails. Diffblue has been earning that trust for a decade.
Oxford University spin-out — formal methods heritage
Fortune 500 customers in financial services, insurance, technology
Diffblue CLI runs locally — your code stays in your environment
On-premises solutions available for regulated environments
Already using Diffblue Cover?
Everything you trust about Diffblue — now working with your existing AI coding platform for even better results, at even greater scale.
Autonomous test generation: See it in action
Free Proof of Value for qualified enterprise teams. Run the Diffblue Testing Agent on your codebase. See the benchmark data. Talk to our engineers.
