mini_program_contracts

Shared contracts for the portable Flutter mini-program platform.

This package holds the stable language shared by mini-program authoring, static artifact delivery, Publisher API backends, host apps, and runtime/tooling packages.

What it exports

• manifest models and cache policy types
• value-based capability IDs
• screen format metadata for Mp JSON screens
• stable action names
• typed action payload models
• host action request/result envelopes
• mini-program screen navigation payloads
• SDK semver compatibility helpers
• stable error codes and feature flag keys

Who should depend on it

• runtime and tooling packages that need to read or validate mini-program manifests
• artifact services and Publisher API tooling that serve or validate contract data
• host apps that implement typed bridge payloads

Most application code should depend on a higher-level package such as the SDK or tooling package. Depend on mini_program_contracts directly when you need the shared wire-level types and constants.

Screen formats

Mp JSON is the default screen format. Missing values decode as mp with schema version 1. Manifests may declare the format explicitly:

{
  "screenFormat": "mp",
  "screenSchemaVersion": 1
}

Unknown non-empty screen format strings are preserved so SDKs can show a controlled unsupported-format error.

Capability IDs

New code should use CapabilityId strings and the constants in CapabilityIds, for example CapabilityIds.auth or CapabilityIds.mediaVideo. The old Capability enum remains available as a deprecated compatibility API while the Mp engine branch migrates callers.