Free, anonymous API-owned scientific capability contracts and domain suggestions. Start here before choosing or funding a quantum job. Inspect separate source, installed, hosted, simulator, live-QPU and public coverage; unknown means unverified. Read schemas, examples and limits; unavailable chemistry, cryptography or hybrid workflows must not be replaced with Bell or promised as execution. This finite registry is not the complete roadmap. Workflow tool references do not promise availability on this endpoint or eligibility for the caller. No account, balance, job, private policy, quote, reservation or hardware execution is accessed. Existing authenticated tools own those operations.