Flyte

Flyte

Flyte is an open source, Apache 2.0 durable AI runtime that orchestrates training, serving, and agent workloads in Python while automatically recovering from infrastructure and code failures.

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Last Updated Oct 22, 2026
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About

Flyte is an open source runtime for building and running AI workloads — batch inference, fine-tuning, pretraining, reinforcement learning, and agent loops — with automatic recovery from both infrastructure failures and code errors. It addresses a common pain point in machine learning pipelines: when one step fails, the whole job often has to be rerun, wasting compute and time. Flyte records input and output for every step so execution resumes from the failed task instead of restarting the pipeline.

The project is licensed under Apache 2.0 and governed under the Linux Foundation AI & Data initiative. Developers define workflows as ordinary code using language-native SDKs (Python, TypeScript, Rust, Go, and Mojo), with a TaskEnvironment construct declaring images, resources, secrets, and retry policy. The same code can run locally, on a dev environment, or on a production cluster. Union.ai offers a managed enterprise distribution of Flyte for teams that want a hosted platform.

Key Features

Durable execution with automatic recovery: Flyte resubmits tasks after OOM kills, preempted spot nodes, GPU disappearances, and node interruptions, sometimes with corrected resource settings, without manual intervention.
Failure-aware retries and resume: Logical failures such as code exceptions or API rate limits trigger retries with the exact same inputs, and completed shards of a job are never rerun.
Workflows in plain code with multiple SDKs: Developers write tasks as ordinary async functions in Python, TypeScript, Rust, Go, or Mojo, using standard control flow for branching, looping, and fan-out — no separate DSL or YAML.
Real-time endpoints and dashboards: The same Python API can serve long-running applications, with native integrations for Streamlit, FastAPI, vLLM, SGLang, and Ollama, including OpenAI-compatible LLM endpoints with model streaming and tensor parallelism.
Broad ecosystem integrations: Official integrations cover Apache Spark, Ray, PyTorch Elastic, BigQuery, Snowflake, Weights & Biases, MLflow, Dask, Databricks, and agent frameworks such as the OpenAI Agents SDK, LangGraph, CrewAI, and Pydantic AI.
Autoscaling and scale-to-zero: Infrastructure scales up and down to match workload demand, and replicas or scaledown for served apps can be set with a single line of configuration.
Production UI and agent tooling: A UI built for production runs supports debugging, and agent code can be sandboxed with every LLM call traced.

Pricing & Fees

  • Pricing: Flyte itself is free and open source under the Apache 2.0 license; enterprise plans through Union.ai are not publicly listed on the pages we reviewed, so check the official site for current terms.
  • License and governance: Apache 2.0 licensed, with open governance under Linux Foundation AI & Data.
  • Interactive environments: Flyte Devbox and a GitHub Codespaces option let developers try the platform quickly, with harness support for tools like Claude Code, Codex CLI, and OpenCode.
  • Documented production users: Case studies on the official site describe usage at Spotify (financial forecasting pipelines), Wayve (petabyte-scale vision workloads for autonomous driving R&D), and Cradle (ML pipelines for protein design).
  • Migration support: Dedicated migration resources exist for teams moving from Flyte 1 to Flyte 2.

Who It's For

Flyte is aimed at machine learning engineers, platform teams, and researchers who run training, batch inference, or agent workloads on variable or spot compute and need pipelines that survive failures. Typical use cases include fine-tuning and pretraining jobs, distributed training with Ray or PyTorch, warehouse queries against BigQuery or Snowflake, and serving LLM endpoints with vLLM or SGLang. It suits organizations that want reproducible, resumable pipelines and observability across experiment and production stages, as well as teams building agent systems that require tracing of every LLM call.

FAQ

What is Flyte?Flyte is an open source, Apache 2.0 durable AI runtime for orchestrating training, serving, and agent workloads, designed to recover automatically from infrastructure and code failures.

Is Flyte free to use?Yes, the open source project is free under the Apache 2.0 license; a managed enterprise offering is available separately through Union.ai, whose pricing is not publicly listed on the pages reviewed.

Which languages and integrations does Flyte support?Flyte provides SDKs for Python, TypeScript, Rust, Go, and Mojo, and integrates with Apache Spark, Ray, PyTorch Elastic, BigQuery, Snowflake, Weights & Biases, MLflow, vLLM, SGLang, LangGraph, CrewAI, and more via official and community plug-ins.

How does Flyte handle failures?It retries failed tasks with their original inputs, backs off on errors such as API rate limits according to a configured retry strategy, resubmits tasks after infrastructure failures, and resumes from the failed step instead of rerunning the whole pipeline.

Who uses Flyte in production?The official site documents case studies from Spotify, Wayve, and Criddle's domain of generative biology — specifically Spotify for financial forecasting, Wayve for autonomous driving research, and Cradle for protein-design machine learning.