Source: https://seerepo.com/compare/unionlabs/union/vs/windmill-labs/windmill
Markdown source: https://seerepo.com/compare/unionlabs/union/vs/windmill-labs/windmill.md
Description: union and windmill share 18 technologies: axum, tower, sqlx-postgres, Postgres, sqlx, Tokio, Svelte, SvelteKit, SQLite, ed25519-dalek, schemars, tracing, tracing-subscriber, tracing-opentelemetry, OpenTelemetry, opentelemetry-otlp, Tailwind CSS, and tailwind-merge. Both are written in Rust.

# union vs windmill

union and windmill share 18 technologies: axum, tower, sqlx-postgres, Postgres, sqlx, Tokio, Svelte, SvelteKit, SQLite, ed25519-dalek, schemars, tracing, tracing-subscriber, tracing-opentelemetry, OpenTelemetry, opentelemetry-otlp, Tailwind CSS, and tailwind-merge. Both are written in Rust.

- [unionlabs/union](https://seerepo.com/r/unionlabs/union): The trust-minimized, zero-knowledge bridging protocol, designed for censorship resistance, extremely high security, and usage in decentralized finance.
- [windmill-labs/windmill](https://seerepo.com/r/windmill-labs/windmill): Code-first platform for workflows, apps and AI agents, on the fastest self-hostable orchestrator (benchmarked against Airflow, Prefect and Temporal). Business teams build with AI, engineers control what ships. Open-source alternative to Lovable, Retool and n8n.

## What they share and what sets them apart

- In common: axum, tower, sqlx-postgres, Postgres, sqlx, Tokio, Svelte, SvelteKit, SQLite, ed25519-dalek, schemars, tracing, tracing-subscriber, tracing-opentelemetry, OpenTelemetry, opentelemetry-otlp, Tailwind CSS, tailwind-merge
- Only in union: net/http, Gorilla, moka, wasmtime, Supabase, @effect/platform, console, Ratatui, crossterm, github.com/rs/zerolog, rehype-stringify, remark, remark-parse, unified, vfile, @effect/opentelemetry
- Only in windmill: async-nats, aws-sdk-sqs, mysql-connector-python, nkeys, postgres-native-tls, postgres-protocol, psycopg, psycopg2-binary, pyairtable, pymongo, rdkafka, rusqlite, s3transfer, tokio-postgres, quick_cache, object_store, MySQL, duckdb, lapin, rumqttc, datafusion, MongoDB, tiberius, Deno, React, idb, lru-cache, OpenAI, Anthropic, matplotlib, seaborn, SQLAlchemy, cryptography, pyjwt, hmac, tower-cookies, jsonwebtoken, oauth2, argon2, aws-sdk-sts, gcp_auth, hkdf, openidconnect, nltk, rmcp, aws-sdk-bedrockruntime, aws-sdk-bedrock, candle-core, candle-nn, candle-transformers, hf-hub, tokenizers, libxml, mail-parser, quick-xml, sendgrid, parquet, pulldown-cmark, yaml-rust, deno_webidl, aws-sdk-secretsmanager, boto3, k8s-openapi, kube, opentelemetry-appender-tracing, opentelemetry-semantic-conventions, prometheus, bollard, tracing-appender, @ai-sdk/react, @assistant-ui/react, ai, yaml, Ajv, style-to-object, xyflow, monaco-editor, Chart.js, ag-grid-community, chartjs-adapter-date-fns, chartjs-plugin-zoom, svelte-range-slider-pips, driver.js, ol, panzoom, @codingame/monaco-vscode-languages-service-override, Mermaid, monaco-vim, xterm, xterm-readline, y-monaco, Lucide, svelte-exmarkdown, highlight.js, dompurify, mdast-util-find-and-replace, pdfjs-dist, rehype-raw, rehype-sanitize, unist-util-visit, Zod

## Side by side

| | union | windmill |
|---|---|---|
| Size | 468,416 lines written, 1,841 code files | 1,458,145 lines written, 4,587 code files |
| Who writes it | 0% of its commits signed by AI. With CodeRabbit | 18.1% of its commits signed by AI. With Claude Code |
| Activity | Last push July 25, 2026, 13,299 commits, 73,725 stars | Last push November 6, 2026, 15,630 commits, 18,428 stars |
| Tests | 120 test files. 10.4% of its code files have a test that imports them | 803 test files. 9.7% of its code files have a test that imports them |

- Size: Lines written by people and agents, without generated ones; code files, without tests.
- Who writes it: A commit counts as AI's when it carries its signature: a Co-Authored-By line, its author name or the merge of its branch.
- Activity: From GitHub and its history, on the day SeeRepo read it.
- Tests: The files that test the code, and the share of code files a test imports.

## Frequently asked questions

### Which is bigger, union or windmill?

windmill, with 1,458,145 lines written; union has 468,416.

The proof: [windmill-labs/windmill's code at commit 9ce2c6b](https://github.com/windmill-labs/windmill/tree/9ce2c6b131f35e29f4ed7020962da1bdae8a44a5)

### Which has more GitHub stars, union or windmill?

union, with 73,725 stars; windmill has 18,428.

The proof: [unionlabs/union on GitHub](https://github.com/unionlabs/union)

### Which has more tests, union or windmill?

windmill, with 803 test files; union has 120.

The proof: [windmill-labs/windmill's code at commit 9ce2c6b](https://github.com/windmill-labs/windmill/tree/9ce2c6b131f35e29f4ed7020962da1bdae8a44a5)

### Which was updated more recently, union or windmill?

windmill: its last push was on November 6, 2026, and union's on July 25, 2026.

The proof: [windmill-labs/windmill's commits on GitHub](https://github.com/windmill-labs/windmill/commits)

### Which has more commits signed by AI, union or windmill?

windmill: an AI signed 18.1% of its commits, with Claude Code.

The proof: [the commits each tool signed in windmill-labs/windmill](https://seerepo.com/r/windmill-labs/windmill/ai)

## Sources

- unionlabs/union: Read on November 5, 2026, at commit 031785b (https://github.com/unionlabs/union/tree/031785bb6dc6b957c624e62bc64c184409c97d7b)
- windmill-labs/windmill: Read on November 6, 2026, at commit 9ce2c6b (https://github.com/windmill-labs/windmill/tree/9ce2c6b131f35e29f4ed7020962da1bdae8a44a5)

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.