routescore.preflight_action.v0 is a public-draft contract for a single, read-only preflight evidence response that an agent, wallet, or treasury workflow can compose before an independently controlled action.

Public draft, not a callable promise

Publication freezes a reviewable vocabulary; it does not mean every action type is implemented. Routescore's shipped reference subset remains POST /api/public/v1/check/swap and the existing policy-evaluation surface. Unsupported inputs stay unsupported. The contract does not execute, sign, route funds, take custody, or provide investment advice.

Versioned artifacts

These URLs are stable within v0. Breaking field, type, enum, or semantic changes require a new major version. Additive and clarifying public-draft changes are recorded in the changelog.

Trust and failure semantics

clear, caution, and unsupported are evidence states, never execution instructions or outcome assurances.
Unknown token state defaults to caution; unavailable required evidence defaults to unsupported rather than a guessed result.
Every response carries source freshness, methodology version, confidence, caveats, and commercial disclosure.
A conforming relay keeps the verdict, reasons, and caveats visible to the end user. See agent skills for Routescore preflight.

Implementation status

The generalized request/response and reserved policy hooks remain draft. Implementers must declare which action types they evaluate and must return an unsupported response for the rest. Routescore is one composable evidence element alongside caller-controlled planning, execution, wallet, and approval systems.