Bezenith

Compute Mint is a gateway that lets coding agents use Meta's Muse Spark Contributor tier safely. Contributor serves the same model about 42× cheaper for a typical agent token mix, in exchange for training rights, but the terms forbid sending anything sensitive, and agent sessions pull secrets and personal data into their context early and carry it forward. In our analysis of 683 of our own agent sessions, a naive switch could send only 8.8% of the tokens. Compute Mint sits on the developer's machine between the agent and the Meta Model API. Every message gets an information-flow label that taints whatever is derived from it. Public work goes to Contributor in a clean context, with emails, phones and keys replaced by reversible placeholders. Credential files hit a floor that no setting can override, and anything unreviewed is held and never sent. A counterfactual ledger records what each request cost, what it would have cost on Standard, and exactly what left the machine. Review decisions become rules, so more of the next session can go to the cheaper lane. On 15 coding tasks × 3 runs against the real Muse Spark API: all-Standard 42/45 accepted for $1.14; Compute Mint 44/45 for $0.46 (2.5× cheaper; 44 vs 42 is run-to-run noise, not a quality claim). 0 planted secrets reached Contributor. In a live Codex session, 29 of 59 calls went to Contributor and 30 were held. Integration is one line: the agent's base_url.