Union is the durable AI runtime your team owns. Turn your data into models, agents and apps with plain Python, on infrastructure you control. If a step fails, it picks up where it stopped.










Six core capabilities in Union.ai that the top AI labs rely on
Union’s control plane orchestrates the work and holds references, never payloads. Verifiable by inspection — topological, not behavioral.
A checkpoint you can’t reproduce is a checkpoint you don’t own. The factory wires teams together through named artifacts.
Every agent is a loop over a model that calls tools. Union makes each agent step durable and replayable, so a crash on step seven resumes where it left off.
Owning your AI starts with a runtime that survives your infrastructure. Pick a workload, pick a failure, and press Run — the task fails, and Union recovers it with no manual intervention.
Union puts LLM providers and self-hosted models behind one gateway with virtual keys, budgets, and guardrails you can customize.
Queues carry priority, concurrency, quotas, and a cluster selector, so a backfill never eats production capacity and a GPU workload lands on the cluster you chose.
“We can scale to 200,000–300,000 pods with the escalation logic baked right in, and the out-of-memory and scheduling headaches I used to fight are simply gone.”
Jay GanbatPrincipal Bioinformatics Engineer · Prima Mente
“Our inference runs exceed the scale limits of a standard EKS cluster. With Union, we can have a single run span multiple clusters while having that single run spawn thousands of GPUs and call hundreds of thousands of actions, all of which are cached durably.”
Hariharan AnanthakrishnanPrincipal Engineer · Artera AI
“Rather than dealing with eight new AWS users and all the permissions, we just set up intern projects… Using Union for compute helps a ton because we're not setting up individual EC2 instances for each one of them.”
Jeff AlbrechtHead of Engineering · LGND
“Initially it was something like four minutes, because we were pulling every layer. Now if I look at the logs, it's always under one second. We never have any issue with cold starts.”
Arka PurkayasthaResearch engineer · Third Dimension AI
“Definitely easier to scale than Ray, since you have a lot more granular control over streaming the parallelism. The parallel async model is nice to work with.”
Patrick SurryChief Data Scientist · Hopper
Union is built on Flyte, the open-source AI runtime we create and maintain under the Linux Foundation AI & Data.
No DSL, no YAML hell. A TaskEnvironment declares images, resources, secrets and retry policy; tasks are plain async functions. Branch, loop and fan out with ordinary control flow — the runtime records every await so a crash resumes instead of restarting.
Bring one workload — training, data, or serving. We'll run it inside your cloud this week, and you can inspect exactly what the control plane sees: references, and nothing else.