Contracts

Contracts define the integration points between your backend, transport, and strategies.

UploadApi

Your backend adapter implements:

• createIntent -- returns a strategy intent describing how the file should be uploaded
• complete -- returns a typed result after the upload finishes
• optional findByChecksum for deduplication
• optional multipart and tus helpers

UploadTransport

Transport handles raw HTTP requests (XHR or fetch). The default implementation uses XHR because it supports upload progress events.

Strategy Contracts

Strategies implement a single method:

start(ctx: StrategyCtx): Promise<void>

start(ctx: StrategyCtx): Promise<void>

The engine provides file, intent, transport, api, and cursor helpers via the context object.

Upload Lifecycle Sequence