Shared language

Glossary and status

Terms, maturity levels, and service expectations used throughout the x429 docs.

Glossary

TermDefinition
AdmissionThe origin accepts the request instead of returning a throttle response.
BindingThe client key or wallet identifier that the ticket is tied to.
DiscoveryThe /.well-known/x429.json document.
Free laneThe guaranteed future slot that requires no payment.
GSLP / policy layerA higher-level guarantee, routing, or service-level policy can reference x429 as its concrete overload coordination primitive.
llms.txtA concise text file that tells agents how to interpret the site and protocol.
MCPModel Context Protocol. MCP servers are good pilot candidates because they are agent-facing and often experience bursty tool traffic.
NonceThe single-use value that prevents replay.
PriorityAn earlier admission class offered at a price.
ResourceThe endpoint or logical capacity pool being scheduled.
SlotThe window from notBefore to notAfter.
Ticket breachA valid ticket presented in-window fails to admit. This should be treated as severe.
x402The intended payment rail for real paid priority. x429 composes with it rather than replacing it.

Maturity labels

LabelMeaning
WorkingImplemented and exercised by tests or simulator.
DraftDesigned and documented, but still likely to change.
PlannedIntended direction, not yet implemented.
Out of v1Explicitly not part of the current milestone.

Suggested SLOs for pilots

  • p99 valid-ticket verification under 10ms at the middleware layer.
  • p95 free-ticket redemption admitted within 1 second of notBefore.
  • 0 successful replay attempts.
  • 0 successful tampered tickets.
  • 0 ticket breaches in controlled load tests.

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