What's this about?
The identical "add email" prompt produced four different providers depending only on repository language: Resend on TypeScript, SendGrid on Python, Postmark on Go, Azure ACS on Java.
What exactly is happening?
The agent reads the repo before choosing, and each language ecosystem has its own gravity — the SDKs, docs and idioms the agent encounters differ per stack. Context outweighs the prompt.
Why is this worth noting?
Practical consequence: your codebase is now a purchasing signal. Vendors will optimize per-ecosystem presence (SDK quality, docs the agent can parse), and identical companies with different stacks will drift toward different supplier sets without anyone deciding to.