import type { LocalAccount } from 'viem/accounts';
import type * as Auth from '../../../internal/Auth.js';
import type * as Db from '../../../db/Db.js';
import type * as Mpp from '../Mpp.js';
/** Resolves the chain declared by a Tempo charge challenge. */
export declare function chainId(input: Mpp.RelayInput): number | undefined;
/** Whether a Tempo charge credential requests platform fee sponsorship. */
export declare function requiresFeePayer(input: Mpp.RelayInput): boolean;
/** Refuses credentials outside the chains served by this API deployment. */
export declare function assertSupportedChain(options: assertSupportedChain.Options): void;
export declare namespace assertSupportedChain {
    /** Chain-selection inputs. */
    type Options = {
        /** Resolved credential chain. */
        chainId: number;
        /** Chains served by this API deployment. */
        supportedChainIds: ReadonlySet<number>;
    };
}
/** Authorizes managed fee sponsorship for one broadcast request. */
export declare function authorizeFeePayer(options: authorizeFeePayer.Options): Promise<LocalAccount | undefined>;
export declare namespace authorizeFeePayer {
    /** Dependencies used to authorize managed fee sponsorship. */
    type Options = {
        /** Credential chain. */
        chainId: number;
        /** Primary database for authoritative billing enforcement. */
        db: Db.Db;
        /** Managed fee-payer account, when configured. */
        feePayer?: LocalAccount | undefined;
        /** MPP credential being broadcast. */
        input: Mpp.RelayInput;
        /** Authenticated request principal. */
        principal?: Auth.Principal | undefined;
    };
}
/** Raised when an MPP credential selects a chain this deployment does not serve. */
export declare class UnsupportedChainError extends Error {
    name: string;
    constructor(chainId: number);
}
/** Raised when a caller is not eligible for managed fee sponsorship. */
export declare class PolicyDeniedError extends Error {
    name: string;
}
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