Modernization Intelligence Platform
Move decades of legacy code into modern software — and prove it still works.
Agentyx turns COBOL mainframes, other legacy code and aging binaries into clean, maintainable, provably-equivalent applications. Deterministic, verified against your original, and traceable line by line — modernization you can actually sign off on.
Free evaluation · your code stays on your machine
Legacy systems still run the business. That's the problem.
The code that processes your loans, ledgers and transactions was written decades ago, by people who have retired. It can't be changed safely, the platform it runs on is end-of-life, and a rewrite is the kind of multi-year, all-or-nothing bet that sinks budgets.
Hand-rewrites drift from the original. AI rewrites that “look right” hide subtle behavioral bugs — a wrong rounding mode, an off-by-one in a grace period — that surface as real money lost. The hard part was never generating modern code. It's proving the modern code does exactly what the original did.
- → It runs your original program as the source of truth, not a best guess.
- → It freezes that truth into tests that fail the moment the behavior diverges.
- → It traces every line back to its origin, so nothing is unaccounted for.
How a modernization runs
Your source goes through Agentyx's Analyzer → Model → Builder pipeline — deterministic end to end, with every output traceable back to the line it came from.
Point it at the source
Install the thin agent for Windows, macOS or Linux and give it a local path to your legacy source — or start a greenfield build with just a goal.
Run it through the engine
Agentyx's Analyzer reads your source, captures it as an internal Model, and the Builder generates the modern code — applying your design standards uniformly. How it works inside is the moat; the output is fully yours and fully inspectable.
Prove it matches the original
Every output is verified against your original program's real behavior and shipped with a test suite that proves equivalence — not a coverage number — and a line-by-line trace.
Get a runnable deliverable
A buildable application, a test suite that proves it matches the original, a full traceability map, and a handoff document land in your folder — ready to review, build and ship.
Built for code you can't afford to get wrong
Deterministic by construction
The same source produces byte-identical output on every run — no randomness, no wall-clock, no model in the hot path. Re-run a modernization and you get the exact same code, so a diff means a real change, never noise.
Correctness proven, not guessed
We verify every output against your original program's real behavior and prove it's equivalent — then capture that proof as a permanent test suite that fails the moment behavior diverges. Quality is judged by whether a test would actually catch a regression, not by a coverage number.
Traceable, line by line
Every line of generated code traces back to the exact source line it came from. A full traceability map ships with the deliverable, so an auditor can follow any business rule from the legacy source to the modern code.
Two targets, your call
Choose an idiomatic modern rewrite — a clean web app with screens, REST and DTOs — or a faithful conversion that preserves the original's behavior to the centavo. Same engine, your choice of output.
No silent gaps
If something can't be translated, it's recorded as an honest, visible gap — never skipped to fake a green build — and measured, so a run that falls short fails rather than ships.
Runs where your code lives
A lightweight agent runs on your own machine. Point it at a local source folder; the autonomous worker does the work and writes the finished deliverable and docs back to a folder you choose. Greenfield builds (no source) are supported too.
What you can bring
- COBOL, assembler and other mainframe & legacy programs — including CICS and BMS screens
- Legacy executables — Windows, MacOS and ELF binaries up to 250MB
- Firmware — Cortex-M, UEFI and baseband images
- Greenfield — start from a goal with no source at all
What you get back
- Modern web apps — Spring Boot services, REST APIs, DTOs and screens
- Modern native binaries — x86-64 and ARM64 across macOS, Windows and Linux
- A test suite that proves the output matches your original's real behavior
- Full line-by-line traceability and a handoff doc for audit and review
Your code stays yours
The worker runs through a thin agent on your own machine. You point it at a folder, you approve what runs on a consent page, and the deliverable is written back locally. Our proprietary engine is the moat — but everything it produces is deterministic, inspectable, and traceable back to your source.
Privacy, data-protection or account-deletion requests: contact@agentyx.dev · Full terms at agentyx.dev/legal.
Where modernization fits
Modernization is the core — and it's safest as part of a sequence: understand the system, prove it's feasible, convert it program by program, and verify every step.
Understand
Grounded, traceable documentation — capture what the system does before you touch it.
Documentation →Prove it's feasible
A fast, load-tested prototype — confirm it can handle your volume and meet your SLAs before you commit.
Feasibility prototype →Modernize
Convert the estate program by program — deterministic, incremental, with behavioral equivalence proven at each step.
You're hereVerify
Independent parallel-run testing — localize any divergence, with audit-grade coverage.
Testing & verification →Modernize your first program today
Start with a free evaluation. Bring a COBOL program or a legacy binary and see the modern code, the tests that prove it, and the line-by-line trace — for yourself.