Configuring Coco

Coco can be configured using a configuration object CocoConfig

import type { Logger, OutputDataCreator, WebSocketFactory } from '@cashu/coco-core';
import type { Repositories } from '@cashu/coco-core/adapter';
import type { Plugin } from '@cashu/coco-core/plugin';

export interface CocoConfig {
  repo: Repositories;
  seedGetter: () => Promise<Uint8Array>;
  logger?: Logger;
  webSocketFactory?: WebSocketFactory;
  plugins?: Plugin[];
  outputDataCreator?: OutputDataCreator;
  watchers?: {
    mintOperationWatcher?: {
      disabled?: boolean;
      watchExistingPendingOnStart?: boolean;
      watchExistingPendingQuotesOnStart?: boolean;
    };
    proofStateWatcher?: {
      disabled?: boolean;
      watchExistingInflightOnStart?: boolean;
    };
    meltQuoteWatcher?: {
      disabled?: boolean;
      watchExistingPendingQuotesOnStart?: boolean;
    };
  };
  processors?: {
    mintOperationProcessor?: {
      disabled?: boolean;
      processIntervalMs?: number;
      maxRetries?: number;
      baseRetryDelayMs?: number;
      initialEnqueueDelayMs?: number;
      autoClaimMintQuotes?: boolean;
    };
    meltSettlementProcessor?: {
      disabled?: boolean;
      initializeExistingPendingOperationsOnStart?: boolean;
    };
  };
}

• repo: A storage adapter that satisfies the Repositories interface. See Storage Adapters for more information
• seedGetter: An asynchronous function that returns a BIP-39 conforming seed as Uint8Array. See BIP-39 for more information.
• logger (optional): An implementation of the Logger interface that Coco will use to log
• webSocketFactory (optional): A factory function that should return a WebSocketLike instance that will be used by Coco to establish websocket connections. If the global WebSocket is not present and webSocketFactory is undefined coco will fallback to polling.
• plugins (optional): An array of Plugin that can be used to inject functionality in Coco. See Plugins for more information.
• outputDataCreator (optional): A session-wide strategy used only to construct Cashu output material. See Custom output construction.
• watchers (optional): Can be used to disable or configure the available watchers. See Watchers & Processors for more information
• processors (optional): Can be used to disable or configure the available processors. See Watchers & Processors for more information

Custom output construction

Pass an OutputDataCreator to replace Cashu output construction for the lifetime of a Coco Session:

import { initializeCoco, type OutputDataCreator } from '@cashu/coco-core';

declare function createRuntimeOutputDataCreator(): OutputDataCreator;

const outputDataCreator = createRuntimeOutputDataCreator();

const coco = await initializeCoco({ repo, seedGetter, outputDataCreator });

The same creator object is used by every mint-and-unit-scoped Wallet Instance and by Coco's mint, send, receive, melt, Restore, and sweep output paths. If it throws, the requesting operation fails; Coco does not fall back to built-in construction. Omitting it preserves the standard cashu-ts behavior.

outputDataCreator is a construction hook, not a persistent proof-conversion hook. It does not replace output reconstruction or guarantee that a custom toProof() implementation will be used later.

Creator results must be OutputDataLike: they must provide a standard blinded message, blinding factor, secret, optional ephemeralE, and toProof() method. Coco persists only those standard fields. When a later operation reads persisted output data, Coco reconstructs the standard cashu-ts OutputData, so its built-in toProof() implementation may be used instead. Custom object identity and a custom toProof() implementation are not preserved across serialization.