Boffin vs Collie

Boffin and Collie are both cli coding agents tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

Boffin

Boffin sits between your codebase and agents like Cursor, Claude Code, or Codex, feeding each edit the specific rules that apply to that file rather than a flat global prompt. The GitHub page describes it as a staff-engineer control layer: it enforces verification steps after code changes and routes constraints designed to protect existing test coverage and API contracts. It ships via npx boffinit, carries an MIT license, and has no hosted API or agent logic of its own — it controls agents, it does not become one. Where it shows limits: if your team needs dynamic rule generation or the constraint set grows complex enough to require its own maintenance cycle, you are now managing a rules system on top of your codebase. Teams that reach that ceiling tend to bake the constraints directly into their CI pipeline instead.

Collie

Collie is a local, open-source coding agent that operates directly on your machine — your file system, your signed-in browser session, your real terminal. The core loop is: you describe the task in plain language, Collie does the actual work, then writes a verification step and runs it before declaring the job complete. That proof-first model is what separates it from a chat assistant. It installs as a desktop app on Windows and macOS, or via a single pip command on Linux. No telemetry, no cloud relay — your files and credentials stay local.

Attribute	Boffin	Collie
Pricing	Free	Free
Free trial	No	No
Open source	Yes	Yes
Has API	No	No
Self-hosted option	Yes	Yes
Platforms	Node.js 18+, Cursor, Claude Code, Codex, OpenCode	Windows, macOS, Linux
Pros	Per-file rule routing rather than a flat global prompt, which means a high-risk payment module gets strict architectural constraints while a utility file gets none — without you manually managing which agent sees what. Post-edit verification hooks built into the control layer, so an agent cannot silently break a test or drift an API contract and move on before you catch it. Plugin configs ship for Claude, Cursor, Windsurf, Codex, and Kiro, which means you are not rewriting integration logic when your team switches agents or runs more than one in parallel. MIT license and npx install with no hosted API, so there is no vendor dependency, no data leaving your environment, and no cost gate between a proof-of-concept and a production deployment. Self-hosted by design, which means your codebase and your rules stay on your infrastructure — a requirement for teams operating under data-residency or IP constraints that a SaaS control layer cannot satisfy.	Runs against your real browser session and signed-in accounts, so tasks like pulling data from a portal or filling a form work without re-authentication or credential sharing with a third party. Writes and runs a verification step before calling a task complete, which means you get a passing test as proof of a bug fix rather than a diff you have to validate yourself. No telemetry and no cloud relay — your source code, files, and session credentials stay on your machine, so it fits workflows where data cannot leave the local environment. One-click desktop install on Windows and macOS with no admin rights required, so setup does not block a developer who lacks elevated permissions on a managed machine. MIT-licensed and self-hosted, so you can inspect the source, fork it, or audit what it does — which matters when you are handing an agent access to your file system and browser.
Cons	Rule files for each scoped path require active maintenance: when a module is restructured or renamed, the corresponding rules become stale and the agent receives either wrong guidance or nothing. There is no automated sync between your file tree and your rule definitions — that is a manual process, and on a codebase with frequent structural changes, it becomes a recurring coordination cost. The tool has no mechanism for generating or updating rules from observed agent behavior; every constraint is hand-authored. Teams whose constraint sets grow beyond a few dozen scoped rules report the rules directory becoming its own engineering artifact — at which point some abandon the layer and encode the same constraints as linter plugins and test fixtures that run in CI regardless of which agent triggered the change. There is no API, so any tooling that needs to query or update rules programmatically — a dashboard, a rule-review workflow, an audit log — requires building directly against the file system. Teams that need visibility into which rules fired on which edits have no built-in observability and must instrument this themselves.	No API surface exists, so you cannot trigger Collie from a script, a CI job, or an external scheduler — any team that needs to embed AI task execution inside an automated pipeline will have to run it interactively or switch to an agent framework that exposes a callable interface. Linux installation requires Python 3.12 or later and a pip install from GitHub; teams on managed Linux environments where Python version is locked by policy will need to resolve that dependency before anything runs. The tool is scoped to single-session, single-machine operation with no documented multi-agent coordination — workflows that need parallel agents handing off between steps are outside what the current architecture supports, and teams building those patterns will move to a framework designed for it.

Bottom line

Boffin runs on Node.js 18+, Cursor, Claude Code, Codex, OpenCode; Collie on Windows, macOS, Linux. Pick the difference that actually blocks you.

Frequently asked questions

What is the difference between Boffin and Collie?

Boffin is Free and open source, while Collie is Free and open source. Compare pricing, free trial, API, platforms, and pros/cons in the table above on AIDiveForge.

Is Boffin better than Collie?

It depends on your workflow. Use the side-by-side attributes (pricing, open source, API, self-hosted, platforms) to decide. AIDiveForge does not rank a universal winner — we publish verified facts so you can choose.

Boffin vs Collie: which should I pick?

Pick Boffin if its pricing model, openness, or platform fit matches your constraints; pick Collie otherwise. Check free-trial availability on each listing if you want to test before committing.

Comparison data is sourced and verified by the AIDiveForge data pipeline. AIDiveForge is editorially independent.