head to head · open source
effect vs openwolf
effect has 17,476 GitHub stars, 895 forks, 253 open issues and last shipped yesterday. openwolf has 2,401 stars, 212 forks, 56 open issues and last shipped 17 days ago. effect leads on adoption by 628% (17,476 vs 2,401 stars). effect is written in TypeScript under MIT; openwolf is written in TypeScript under AGPL-3.0. effect has attracted 5% as many forks as stars, openwolf 9%. effect was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (cli, observability), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| effect | openwolf | |
|---|---|---|
| GitHub stars | ★ 17K | ★ 2.4K |
| License | MIT | AGPL-3.0 |
| Written in | TypeScript | TypeScript |
| Last push | 2026-11-04 | 2026-10-19 |
| Forks | ⑂ 895 | ⑂ 212 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick effect if
- You weight community size — 17K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick openwolf if
- You want the openwolf feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches TypeScript
- You evaluated both and openwolf fits your workflow better
About effect
Effect Effect is a library for building robust, maintainable, type safe, and production grade applications in TypeScript. It helps you handle the hard problems at scale: typed errors, dependency injection, structured concurrency, scheduling, tracing, and unified schema validation. Effect V4 is currently a release candidate. The main branch contains v4 development. Install V4 RC Requirements TypeScript 5.9 or newer. TypeScript 7 is recommended for the best performance and compatibility with Effect's TypeScript tooling. Node.js 18 or newer is the general minimum for running Effect on Node.js. Some integration…
read the full effect overview →
About openwolf
OpenWolf Keep project memory across your coding agents. OpenWolf keeps task context, project maps and known fixes in one local folder. Help Claude Code, Codex and OpenCode continue saved work and find relevant code. Reduce repeated context and review recorded token usage by agent and model. Memory and indexing run locally without extra model calls. Hooks: Claude Code, Codex CLI · Plugin: OpenCode · Compatible hooks: Grok Build · Context only: Cursor, Gemini CLI, Antigravity What it does A coding session produces useful context: the task objective, files changed, failed tests and the next action. That information…
read the full openwolf overview →
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Frequently asked questions
Is effect or openwolf more popular?
effect has 17,476 GitHub stars and openwolf has 2,401. effect has the larger community by that measure.
Are effect and openwolf free?
Both are open source. effect is licensed under MIT and openwolf under AGPL-3.0. Neither carries a licence fee.
What is the difference between effect and openwolf?
effect is written in TypeScript and openwolf in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, effect or openwolf?
Choose effect if you want the larger community (17,476 stars) or its MIT licence terms. Choose openwolf if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.