kitio.aimini-SWE-agent vs Butterfish
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. mini-SWE-agent starts at Free and Butterfish starts at Free. Check both pricing pages for current plans.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Bash-only agent loop
- Works with any model via LiteLLM
- Docker and sandbox environments
- SWE-bench batch runner
- Trajectory inspector
- Python bindings
- AI prompts inside bash and zsh
- Shell history as context
- Command autocomplete from AI
- Goal mode agent
- Neovim plugin
| Feature | mini-SWE-agent | Butterfish |
|---|---|---|
| Best for | Minimal open-source coding agent that works through bash alone | Open-source shell wrapper that adds AI prompts to bash and zsh |
| Category | Coding | Coding |
| Pricing model | Free | Free |
| Starting price | Free | Free |
| Free plan | Yes, fully free | Yes, fully free |
| Made by | SWE-agent team (Princeton and Stanford) | Peter Bakkum |
| Based in | United States | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
mini-SWE-agent starts at Free and Butterfish starts at Free. Check both pricing pages for current plans.
Free plan
Cheapest paid plan
Top plan
Free trial
Prices in USD, checked Nov 5, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
mini-SWE-agent
- Small codebase that is easy to read and modify
- Model-agnostic through common LLM routers
- Strong SWE-bench results for its size
- No graphical interface
- You pay for your own model API usage
- Aimed more at research than everyday editing
Butterfish
- Free and MIT licensed
- No copy and paste between tools
- Keeps your existing shell setup
- Needs your own OpenAI-compatible API key
- No Windows support
- Agent mode can run commands on your system
Which one should you choose?
Choose mini-SWE-agent if you want:
- Small codebase that is easy to read and modify
- Model-agnostic through common LLM routers
- Strong SWE-bench results for its size
Watch out: no graphical interface.
Choose Butterfish if you want:
- Free and MIT licensed
- No copy and paste between tools
- Keeps your existing shell setup
Watch out: needs your own openai-compatible api key.
mini-SWE-agent vs Butterfish FAQ
What is the difference between mini-SWE-agent and Butterfish?
mini-SWE-agent: Minimal open-source coding agent that works through bash alone. Butterfish: Open-source shell wrapper that adds AI prompts to bash and zsh. Both are coding tools.
Is mini-SWE-agent or Butterfish cheaper?
mini-SWE-agent starts at Free and Butterfish starts at Free. Check both pricing pages for current plans.
Do mini-SWE-agent and Butterfish have free plans?
mini-SWE-agent: Yes, fully free. Butterfish: Yes, fully free.
Who makes mini-SWE-agent?
mini-SWE-agent is made by SWE-agent team (Princeton and Stanford), based in United States.
Who makes Butterfish?
Butterfish is made by Peter Bakkum.
Which should I choose, mini-SWE-agent or Butterfish?
Choose mini-SWE-agent if you value small codebase that is easy to read and modify and model-agnostic through common llm routers. Choose Butterfish if you value free and mit licensed and no copy and paste between tools.