v0.1.89

🚀 Release Highlights — v0.1.89 (2026-05-22)

v0.1.89 completes the follow-up Antigravity CLI integration pass after v0.1.88 introduced the first backend. This release focuses on reliability in real MassGen coordination runs: workflow-tool parity, auth checks, workspace write isolation, native hooks, and prompt affordance gating.

🛰️ Workflow-Mode Parity

• Antigravity now mirrors Gemini CLI's new_answer / vote workflow handling
• vote is hidden when no candidate answers exist, keeping agents in new_answer_only mode
• Post-evaluation prompts guard against stale new_answer, vote, or stop calls
• Duplicate parsed workflow calls are suppressed within a single turn

🧰 Workspace Write Reliability

• --add-dir <cwd> registers the MassGen workspace with agy so file tools write where peers and snapshots can see outputs
• Workspace-root .antigravitycli/ marker prevents agy's upward project discovery from adopting a parent project
• .antigravity/ and .antigravitycli/ are ignored as runtime artifacts

🔐 Auth + Binary Health Checks

• Backend construction now verifies agy --version
• Runs fail fast when no GEMINI_API_KEY, GOOGLE_API_KEY, or cached Google OAuth credentials are available
• Docker mode still requires API-key auth because OAuth state does not cross container boundaries

🔌 Native Hooks

• Antigravity hooks now emit standalone hooks.json
• settings.json enables hooks through enableJsonHooks
• Native hook adapter docs now reflect Antigravity's storage model rather than Gemini CLI's embedded settings hook model

🧭 Prompt Guardrails

• TaskContextSection advertises spawn_subagents only when subagents are enabled
• Multimodal-only agents keep read_media context guidance without phantom subagent MCP affordances

🧪 Tests

• massgen/tests/test_antigravity_cli_backend.py expanded to cover health checks, authentication, workspace anchoring, --add-dir, hooks.json, workflow filtering, duplicate tool-call suppression, multimodal prompt flattening, cancellation cleanup, and agent-id propagation
• massgen/tests/test_system_prompt_sections.py covers subagent affordance gating

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📖 Getting Started

• Quick Start Guide
• Install:

  pip install massgen==0.1.89
  curl -fsSL https://antigravity.google/cli/install.sh | bash

• Try It:

  uv run massgen --config massgen/configs/features/fast_iteration_gemini_antigravity.yaml "Create an svg of an AI agent coding."

What's Changed

• feat: harden Antigravity CLI backend for v0.1.89 by @ncrispino in #1099
• docs: docs for v0.1.89 by @Henry-811 in #1101
• feat: v0.1.89 by @Henry-811 in #1100

Full Changelog: v0.1.88...v0.1.89