seisei

Provider-neutral typed generation contracts for Dart and Flutter apps.

This package defines the core Seisei API: requests, responses, streamed chunks, provider availability, capabilities, privacy policy, tool descriptors, and structured error types.

Streamed chunks distinguish complete output from structured snapshots:

• GenerationChunk.value is the terminal decoded value.
• GenerationChunk.partialValue is an optional decoded partial snapshot.
• GenerationChunk.structuredPatches carries path-level structured updates.
• GenerationChunk.delta is for incremental text.

Use diffStructuredValues(previous, next) when a provider receives structured snapshots and needs stable add, replace, and remove patches for changed paths.

It does not include Apple Foundation Models bindings, cloud providers, routing policy, schema helpers, test fakes, or UI rendering. Those live in separate Seisei packages.