2.1.0 – Sep 25, 2026

2.1.0 (2026-09-25)

Features

• modeling: read negotiated packed membership substeps (8d45756)

  Add logical v8 decoding alongside the unchanged v7 metadata contract. Advertise decoder support automatically through the WebSocket handshake, while retaining older Runtime responses.

Bug Fixes

• modeling: replay ancestors created in earlier commit substeps (8179c8c)

  A first commit retains readStateIndex -1 even after earlier substeps create parent relationships. Resolve later ancestor reads at their existing commit boundary while retaining rejection of an invalid initial-substep read.

Documentation

• readme: keep the SDK introduction timeless [skip ci] (951781a)

  Restore the concise product-oriented README and document its scope in AGENTS.md. No code or published artifacts change.

• readme: restore the concise SDK introduction (a68b0d4)

  Keep the README focused on getting started and link to the detailed upgrade guidance instead of repeating Model contracts and transport configuration.

Dependency updates

• bump com.fasterxml.jackson:jackson-bom from 2.22.2 to 2.22.3 (400849d)

  com.fasterxml.jackson:jackson-bom: 2.22.2 -> 2.22.3

Code Refactoring

• websocket: negotiate model membership versions automatically (0466d88)

  Decoder capabilities belong to the protocol handshake. Remove the unreleased application property and defaults-version gate while retaining compatible responses for older peers.

Tests

• modeling: preserve substeps in mixed membership responses (1be6fe6)

  Pin the existing v7 layout and full-membership replay contract so Runtime fallback remains compatible with current readers. Clarify ordered cold replay in the Java and Kotlin guidance.

Chores

• worktrees: keep changes in ignored local worktrees (f2f6c1b)