Donate

Stella is free software. There is no account, no subscription, no telemetry endpoint, and no upsell — and keeping it that way is the point.

If Stella saves you time or money, please consider sponsoring its development:

Why sponsorship matters here

Stella is not a thin wrapper around one vendor's API. It is a large, serious piece of systems engineering, built and maintained by one person:

• A workspace of focused Rust crates — a deterministic agent engine, a staged inference pipeline with independent judging, a tree-sitter code graph, a bi-temporal context store, a multi-tab terminal UI, fleet orchestration over git worktrees, and native wire adapters for nine hosted providers plus any local OpenAI-compatible server.
• Verification you can trust — witness tests replayed against the previous code in a shadow worktree, fail→pass flip oracles, and cross-family judges are much harder to build than "the model said it's done." They are also what makes an agent worth using unattended.
• Real, ongoing costs. Developing, benchmarking, and regression-testing an agent against frontier models is paid for in real API bills — every self-improvement benchmark run, every provider-adapter conformance pass, every multi-model judge evaluation costs actual money. Sponsorship goes directly to keeping that work funded.

What open source is supposed to look like

Stella is built on a few non-negotiable principles:

• No phone-home. The only network traffic Stella produces goes to the model provider you chose. All telemetry — executions, tokens, cost, the files-touched ledger — lands in a local SQLite database on your disk and never leaves your machine.
• Bring your own key. Your credentials, your provider relationship, your bill. No middleman markup, no metered proxy, no lock-in.
• Model and vendor agnostic. Anthropic, OpenAI, Google (Gemini and Vertex), Amazon Bedrock, xAI, DeepSeek, Z.ai, OpenRouter, or any local OpenAI-compatible server — pick per agent, per role, per run. Stella has no favorite and takes no rebate.
• Dual-licensed for everyone. Stella is licensed under MIT OR Apache-2.0 — you choose the license that fits. Individuals typically take MIT's simplicity; enterprises typically prefer Apache 2.0 for its explicit patent grant. Either way it is free to use, fork, embed, and ship.

That combination — local-first, BYOK, vendor-neutral, permissively licensed — is what open source is supposed to be like. It is also precisely the combination that no venture-funded agent product can offer you, because there is nothing to monetize in it.

Other ways to help

Sponsorship is the most direct support, but not the only kind:

• Star and share the repo — discovery is oxygen for independent projects.
• File sharp issues with reproductions; fix one if you can.
• Write about your setup — provider configs, fleet plans, and skills that worked for you help the next person.

Thank you for using Stella — and thank you for keeping independent, local-first developer tooling alive.

github.com/sponsors/macanderson