v1.18.2

Release Notes - v1.18.2

Highlights

• Continuation-safe agent state persistence with new serialization helpers.
• MessageStore serialization is now round-trip safe and section-aware.
• Metadata preservation fixes for slim agent state snapshots.

Behavior Changes

MessageStore toArray Structure

• MessageStore::toArray() now returns a structured payload with sections and parameters instead of a flat messages list.
• Use MessageStore::toFlatArray() to obtain the previous flat messages array format.

New Features

Agent Continuation APIs

• Added AgentState::withUserMessage() for multi-turn continuation.
• Added AgentState::forContinuation() to reset execution state (steps, cache, usage, timing) while preserving conversation history.

Continuation Serializer

• Added ContinuationAgentStateSerializer with ContinuationSerializationConfig to persist multi-turn state with retention limits.
• Supports truncation, tool-result omission, and tool-arg redaction while preserving _metadata.

Bug Fixes

Metadata Preservation

• SlimAgentStateSerializer now emits _metadata (with metadata alias support) so tool calls/results survive round-trips.
• MessageInput::fromArray() now accepts metadata as a fallback alias for _metadata.

Serialization Round-Trip

• MessageStore serialization now round-trips sections, messages, and parameters without data loss.

Tests

• Added round-trip tests for MessageStore and continuation serialization.
• Added AgentState continuation tests covering reset semantics and message appending.