BYOK: Why We Let You Bring Your Own API Key
The Vendor Lock-In Problem
Every AI-powered developer tool faces the same dilemma: which LLM to use?
Pick one provider and you're locked in. Their pricing changes, your margins evaporate. Their model gets worse (it happens), your product gets worse. They deprecate the model, you scramble to migrate.
We decided not to choose. Instead, we let you choose.
What Is BYOK?
BYOK — Bring Your Own Key — means you plug in your own API key from any supported LLM provider. Your key, your costs, your model choice.
SOLO currently supports:
You pick the model. You can switch anytime. Your API key is encrypted with AES-256-GCM before storage — we never see the plaintext.
Why Not Just Use One Model?
We tested every major model against our agent pipeline. The results varied wildly by task:
Gemini 2.5 Flash was fastest and cheapest. It handles simple fixes (typos, copy changes, CSS tweaks) for less than a penny per PR. Perfect for high-volume, low-complexity tasks.
Claude Sonnet 4 produced the highest-quality multi-file refactors. When the agent needs to understand complex type relationships across files, Sonnet consistently outperformed others.
GPT-4.1 split the difference. Good at code generation, competitive pricing, strong at following instructions. The most predictable model — fewest surprises, fewest brilliances.
No single model is "best." The best model depends on the task, your budget, and your risk tolerance.
The Cost Math
Let's do the math for a typical month of agent activity:
100 PRs/month, average 3 iterations each, ~2K tokens per iteration:
On the Free plan, SOLO provides a platform Gemini key with 5 PRs/month. You pay nothing. On Starter ($19/mo) and Pro ($39/mo), you bring your own key and get unlimited PRs — you only pay what you use.
Key Rotation and Security
Your API key is encrypted at rest using AES-256-GCM with a per-environment secret. The encryption flow:
You can rotate your key anytime. Delete and re-add — the old encrypted blob is purged immediately.
Why Not Proxy Through Our Account?
Some tools proxy LLM calls through their own API key and charge a markup. We considered this and rejected it for three reasons:
Getting Started with BYOK
The Free plan doesn't require BYOK — you get 5 agent PRs/month using our platform Gemini key. BYOK unlocks unlimited PRs on Starter and Pro.
SOLO gives you full control over your AI stack. Your key, your model, your costs.
- Google Gemini — Gemini 2.5 Pro, Gemini 2.5 Flash (fast and cheap)
- Anthropic — Claude Sonnet 4, Claude Opus 4
- OpenAI — GPT-4.1, o3, o4-mini