Merge pull request #1022 from massgen/dev/v0.1.68

feat: v0.1.68

Author: Henry-811

AGENTS.md

@@ -306,6 +306,7 @@ Detailed documentation for specific modules lives in `docs/modules/`. **Always c
 - `docs/modules/interactive_mode.md` - Interactive mode architecture, launch_run MCP, system prompts, project workspace
 - `docs/modules/worktrees.md` - Worktree lifecycle, branch naming, scratch archives, system prompt integration
 - `docs/modules/composition.md` - **Composable primitives, phase architecture, domain-specific checklist gates** — how personas, eval criteria, decomposition, and planning compose for maximum quality
+- `docs/modules/checkpoint.md` - **Checkpoint coordination mode** — tool schema, fresh agent instantiation, state save/restore, workspace propagation, WebUI behavior
 - `docs/modules/coordination_workflow.md` - **Round lifecycle and checklist workflow** — the implement → evaluate → submit cycle, when to call `submit_checklist` vs `new_answer`, and why agents must not re-evaluate within a round
 
 ## MassGen Skills

CHANGELOG.md

@@ -9,17 +9,32 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Recent Releases
 
+**v0.1.68 (March 25, 2026)** - Checkpoint Mode
+New checkpoint coordination mode with delegator pattern — main agent plans solo then delegates to team via `checkpoint()` tool. LLM API circuit breaker for 429 handling. WebUI checkpoint support. LiteLLM supply chain fix.
+
 **v0.1.67 (March 23, 2026)** - Modernized WebUI
 Complete WebUI redesign with inline final answers, keyboard shortcuts, and Zustand state management. RoundBudgetGuardHook for per-round cost control. Unified parallel pre-collab phases. Regression guard for safe iterations.
 
 **v0.1.66 (March 20, 2026)** - Step Mode
 New `--step` CLI mode for external orchestrators to run one agent for one step then exit. Powers massgen-refinery plugin step mode. Codex Windows UTF-8 fixes and console text sanitization.
 
-**v0.1.65 (March 18, 2026)** - MassGen Refinery Plugin
-Standalone MCP servers (quality, workflow, media) bring MassGen's checklist-based evaluation and multi-round refinement to Claude Code through the massgen-refinery plugin. Single-agent refinement working; multi-agent experimental.
-
 ---
 
+## [0.1.68] - 2026-03-25
+
+### Added
+- **Checkpoint Coordination Mode** ([#1028](https://github.com/massgen/MassGen/pull/1028)): New delegator pattern — main agent plans solo then calls `checkpoint()` to delegate execution to fresh agent instances with clean backends and cloned workspaces
+- **WebUI Checkpoint Support** ([#1028](https://github.com/massgen/MassGen/pull/1028)): Checkpoint mode display integrated into the modernized WebUI
+- **LLM API Circuit Breaker** ([#1024](https://github.com/massgen/MassGen/pull/1024)): Automatic 429 rate limit handling with circuit breaker pattern for Claude backend
+
+### Fixed
+- **LiteLLM Supply Chain Fix** ([#1025](https://github.com/massgen/MassGen/pull/1025)): Pinned litellm<=1.82.6 and committed uv.lock to prevent dependency attacks
+
+### Technical Details
+- **Major Focus**: Checkpoint Mode — delegator pattern for multi-agent coordination
+- **PRs Merged**: [#1028](https://github.com/massgen/MassGen/pull/1028), [#1025](https://github.com/massgen/MassGen/pull/1025), [#1024](https://github.com/massgen/MassGen/pull/1024)
+- **Contributors**: @ncrispino, @amabito, @HenryQi and the MassGen team
+
 ## [0.1.67] - 2026-03-23
 
 ### Added

CLAUDE.md

@@ -306,6 +306,7 @@ Detailed documentation for specific modules lives in `docs/modules/`. **Always c
 - `docs/modules/interactive_mode.md` - Interactive mode architecture, launch_run MCP, system prompts, project workspace
 - `docs/modules/worktrees.md` - Worktree lifecycle, branch naming, scratch archives, system prompt integration
 - `docs/modules/composition.md` - **Composable primitives, phase architecture, domain-specific checklist gates** — how personas, eval criteria, decomposition, and planning compose for maximum quality
+- `docs/modules/checkpoint.md` - **Checkpoint coordination mode** — tool schema, fresh agent instantiation, state save/restore, workspace propagation, WebUI behavior
 - `docs/modules/coordination_workflow.md` - **Round lifecycle and checklist workflow** — the implement → evaluate → submit cycle, when to call `submit_checklist` vs `new_answer`, and why agents must not re-evaluate within a round
 
 ## MassGen Skills

CONTRIBUTING.md

@@ -359,7 +359,7 @@ Create a `.env` file in the `massgen` directory as described in [README](README.
 
 ## 🔧 Development Workflow
 
-> **Important**: Our next version is v0.1.68. If you want to contribute, please contribute to the `dev/v0.1.68` branch (or `main` if dev/v0.1.68 doesn't exist yet).
+> **Important**: Our next version is v0.1.69. If you want to contribute, please contribute to the `dev/v0.1.69` branch (or `main` if dev/v0.1.69 doesn't exist yet).
 
 ### 1. Create Feature Branch
 
@@ -368,7 +368,7 @@ Create a `.env` file in the `massgen` directory as described in [README](README.
 git fetch upstream
 
 # Create feature branch from dev/v0.1.60 (or main if dev branch doesn't exist yet)
-git checkout -b feature/your-feature-name upstream/dev/v0.1.68
+git checkout -b feature/your-feature-name upstream/dev/v0.1.69
 ```
 
 ### 2. Make Your Changes
@@ -507,7 +507,7 @@ git push origin feature/your-feature-name
 ```
 
 Then create a pull request on GitHub:
-- Base branch: `dev/v0.1.68` (or `main` if dev branch doesn't exist yet)
+- Base branch: `dev/v0.1.69` (or `main` if dev branch doesn't exist yet)
 - Compare branch: `feature/your-feature-name`
 - Add clear description of changes
 - Link any related issues
@@ -617,7 +617,7 @@ Have a significant feature idea not covered by existing tracks?
 - [ ] Tests pass locally
 - [ ] Documentation is updated if needed
 - [ ] Commit messages follow convention
-- [ ] PR targets `dev/v0.1.68` branch (or `main` if dev branch doesn't exist yet)
+- [ ] PR targets `dev/v0.1.69` branch (or `main` if dev branch doesn't exist yet)
 
 ### PR Description Should Include
 

README.md

@@ -69,7 +69,7 @@ This project started with the "threads of thought" and "iterative refinement" id
 <details open>
 <summary><h3>🆕 Latest Features</h3></summary>
 
-- [v0.1.67 Features](#-latest-features-v0167)
+- [v0.1.68 Features](#-latest-features-v0168)
 </details>
 
 <details open>
@@ -122,15 +122,15 @@ This project started with the "threads of thought" and "iterative refinement" id
 <details open>
 <summary><h3>🗺️ Roadmap</h3></summary>
 
-- [Recent Achievements (v0.1.67)](#recent-achievements-v0167)
-- [Previous Achievements (v0.0.3 - v0.1.66)](#previous-achievements-v003---v0166)
+- [Recent Achievements (v0.1.68)](#recent-achievements-v0168)
+- [Previous Achievements (v0.0.3 - v0.1.67)](#previous-achievements-v003---v0167)
 - [Key Future Enhancements](#key-future-enhancements)
   - Bug Fixes & Backend Improvements
   - Advanced Agent Collaboration
   - Expanded Model, Tool & Agent Integrations
   - Improved Performance & Scalability
   - Enhanced Developer Experience
-- [v0.1.68 Roadmap](#v0168-roadmap)
+- [v0.1.69 Roadmap](#v0169-roadmap)
 </details>
 
 <details open>
@@ -155,19 +155,20 @@ This project started with the "threads of thought" and "iterative refinement" id
 
 ---
 
-## 🆕 Latest Features (v0.1.67)
+## 🆕 Latest Features (v0.1.68)
 
-**🎉 Released: March 23, 2026**
+**🎉 Released: March 25, 2026**
 
-**What's New in v0.1.67:**
-- **🖥️ Modernized WebUI** - Complete UI redesign with inline final answers, keyboard shortcuts, and Zustand state management.
-- **💰 RoundBudgetGuardHook** - Per-round cost enforcement prevents unexpected API bill overruns.
-- **🎭 Unified Pre-Collab** - Personas, evaluation criteria, and prompt improvement run in parallel.
+**What's New in v0.1.68:**
+- **🔀 Checkpoint Mode** - Main agent plans solo then delegates to the team via `checkpoint()` tool with fresh agent instances.
+- **⚡ LLM API Circuit Breaker** - Automatic 429 rate limit handling for Claude backend.
+- **🖥️ WebUI Checkpoint Support** - Checkpoint mode display integrated into the modernized WebUI.
+- **🔒 LiteLLM Fix** - Supply chain protection with pinned dependency and committed lock file.
 
-**Try v0.1.67 Features:**
+**Try v0.1.68 Features:**
 ```bash
-pip install massgen==0.1.67
-# Try the modernized WebUI
+pip install massgen==0.1.68
+# Try checkpoint mode
 uv run massgen --web
 ```
 
@@ -1240,17 +1241,19 @@ MassGen is currently in its foundational stage, with a focus on parallel, asynch
 
 ⚠️ **Early Stage Notice:** As MassGen is in active development, please expect upcoming breaking architecture changes as we continue to refine and improve the system.
 
-### Recent Achievements (v0.1.67)
+### Recent Achievements (v0.1.68)
 
-**🎉 Released: March 23, 2026**
+**🎉 Released: March 25, 2026**
 
-#### Modernized WebUI & Quality
-- **Modernized WebUI** ([#1016](https://github.com/massgen/MassGen/pull/1016)): Complete UI redesign with inline final answers, keyboard shortcuts, and Zustand state management
-- **RoundBudgetGuardHook** ([#1013](https://github.com/massgen/MassGen/pull/1013)): Per-round cost enforcement with configurable warning thresholds
-- **Unified Pre-Collab** ([#1016](https://github.com/massgen/MassGen/pull/1016)): Personas, evaluation criteria, and prompt improvement run in parallel
-- **Regression Guard** ([#1016](https://github.com/massgen/MassGen/pull/1016)): Blind A/B verification subagent before submitting revisions
+#### Checkpoint Mode
+- **Checkpoint Coordination Mode** ([#1028](https://github.com/massgen/MassGen/pull/1028)): Delegator pattern — main agent plans solo then delegates to team via `checkpoint()` tool with fresh agent instances
+- **WebUI Checkpoint Support** ([#1028](https://github.com/massgen/MassGen/pull/1028)): Checkpoint mode display in the modernized WebUI
+- **LLM API Circuit Breaker** ([#1024](https://github.com/massgen/MassGen/pull/1024)): Automatic 429 rate limit handling with circuit breaker pattern (currently Claude backend only)
+- **LiteLLM Supply Chain Fix** ([#1025](https://github.com/massgen/MassGen/pull/1025)): Pinned litellm<=1.82.6 and committed uv.lock
 
-### Previous Achievements (v0.0.3 - v0.1.66)
+### Previous Achievements (v0.0.3 - v0.1.67)
+
+✅ **Modernized WebUI (v0.1.67)**: Complete WebUI redesign with inline final answers, keyboard shortcuts, and Zustand state management. RoundBudgetGuardHook for per-round cost control. Unified parallel pre-collab phases. Regression guard.
 
 ✅ **Step Mode (v0.1.66)**: New `--step` CLI mode for external orchestrators. Powers massgen-refinery plugin step mode. Codex Windows UTF-8 fixes and console text sanitization.
 
@@ -1529,9 +1532,9 @@ MassGen is currently in its foundational stage, with a focus on parallel, asynch
 
 We welcome community contributions to achieve these goals.
 
-### v0.1.68 Roadmap
+### v0.1.69 Roadmap
 
-Version 0.1.68 focuses on cloud execution:
+Version 0.1.69 focuses on cloud execution:
 
 #### Planned Features
 - **Cloud Modal MVP** ([#982](https://github.com/massgen/MassGen/issues/982)): Run MassGen as a cloud job on Modal

README_PYPI.md

@@ -68,7 +68,7 @@ This project started with the "threads of thought" and "iterative refinement" id
 <details open>
 <summary><h3>🆕 Latest Features</h3></summary>
 
-- [v0.1.67 Features](#-latest-features-v0167)
+- [v0.1.68 Features](#-latest-features-v0168)
 </details>
 
 <details open>
@@ -121,15 +121,15 @@ This project started with the "threads of thought" and "iterative refinement" id
 <details open>
 <summary><h3>🗺️ Roadmap</h3></summary>
 
-- [Recent Achievements (v0.1.67)](#recent-achievements-v0167)
-- [Previous Achievements (v0.0.3 - v0.1.66)](#previous-achievements-v003---v0166)
+- [Recent Achievements (v0.1.68)](#recent-achievements-v0168)
+- [Previous Achievements (v0.0.3 - v0.1.67)](#previous-achievements-v003---v0167)
 - [Key Future Enhancements](#key-future-enhancements)
   - Bug Fixes & Backend Improvements
   - Advanced Agent Collaboration
   - Expanded Model, Tool & Agent Integrations
   - Improved Performance & Scalability
   - Enhanced Developer Experience
-- [v0.1.68 Roadmap](#v0168-roadmap)
+- [v0.1.69 Roadmap](#v0169-roadmap)
 </details>
 
 <details open>
@@ -154,19 +154,20 @@ This project started with the "threads of thought" and "iterative refinement" id
 
 ---
 
-## 🆕 Latest Features (v0.1.67)
+## 🆕 Latest Features (v0.1.68)
 
-**🎉 Released: March 23, 2026**
+**🎉 Released: March 25, 2026**
 
-**What's New in v0.1.67:**
-- **🖥️ Modernized WebUI** - Complete UI redesign with inline final answers, keyboard shortcuts, and Zustand state management.
-- **💰 RoundBudgetGuardHook** - Per-round cost enforcement prevents unexpected API bill overruns.
-- **🎭 Unified Pre-Collab** - Personas, evaluation criteria, and prompt improvement run in parallel.
+**What's New in v0.1.68:**
+- **🔀 Checkpoint Mode** - Main agent plans solo then delegates to the team via `checkpoint()` tool with fresh agent instances.
+- **⚡ LLM API Circuit Breaker** - Automatic 429 rate limit handling for Claude backend.
+- **🖥️ WebUI Checkpoint Support** - Checkpoint mode display integrated into the modernized WebUI.
+- **🔒 LiteLLM Fix** - Supply chain protection with pinned dependency and committed lock file.
 
-**Try v0.1.67 Features:**
+**Try v0.1.68 Features:**
 ```bash
-pip install massgen==0.1.67
-# Try the modernized WebUI
+pip install massgen==0.1.68
+# Try checkpoint mode
 uv run massgen --web
 ```
 
@@ -1239,17 +1240,19 @@ MassGen is currently in its foundational stage, with a focus on parallel, asynch
 
 ⚠️ **Early Stage Notice:** As MassGen is in active development, please expect upcoming breaking architecture changes as we continue to refine and improve the system.
 
-### Recent Achievements (v0.1.67)
+### Recent Achievements (v0.1.68)
 
-**🎉 Released: March 23, 2026**
+**🎉 Released: March 25, 2026**
 
-#### Modernized WebUI & Quality
-- **Modernized WebUI** ([#1016](https://github.com/massgen/MassGen/pull/1016)): Complete UI redesign with inline final answers, keyboard shortcuts, and Zustand state management
-- **RoundBudgetGuardHook** ([#1013](https://github.com/massgen/MassGen/pull/1013)): Per-round cost enforcement with configurable warning thresholds
-- **Unified Pre-Collab** ([#1016](https://github.com/massgen/MassGen/pull/1016)): Personas, evaluation criteria, and prompt improvement run in parallel
-- **Regression Guard** ([#1016](https://github.com/massgen/MassGen/pull/1016)): Blind A/B verification subagent before submitting revisions
+#### Checkpoint Mode
+- **Checkpoint Coordination Mode** ([#1028](https://github.com/massgen/MassGen/pull/1028)): Delegator pattern — main agent plans solo then delegates to team via `checkpoint()` tool with fresh agent instances
+- **WebUI Checkpoint Support** ([#1028](https://github.com/massgen/MassGen/pull/1028)): Checkpoint mode display in the modernized WebUI
+- **LLM API Circuit Breaker** ([#1024](https://github.com/massgen/MassGen/pull/1024)): Automatic 429 rate limit handling with circuit breaker pattern (currently Claude backend only)
+- **LiteLLM Supply Chain Fix** ([#1025](https://github.com/massgen/MassGen/pull/1025)): Pinned litellm<=1.82.6 and committed uv.lock
 
-### Previous Achievements (v0.0.3 - v0.1.66)
+### Previous Achievements (v0.0.3 - v0.1.67)
+
+✅ **Modernized WebUI (v0.1.67)**: Complete WebUI redesign with inline final answers, keyboard shortcuts, and Zustand state management. RoundBudgetGuardHook for per-round cost control. Unified parallel pre-collab phases. Regression guard.
 
 ✅ **Step Mode (v0.1.66)**: New `--step` CLI mode for external orchestrators. Powers massgen-refinery plugin step mode. Codex Windows UTF-8 fixes and console text sanitization.
 
@@ -1528,9 +1531,9 @@ MassGen is currently in its foundational stage, with a focus on parallel, asynch
 
 We welcome community contributions to achieve these goals.
 
-### v0.1.68 Roadmap
+### v0.1.69 Roadmap
 
-Version 0.1.68 focuses on cloud execution:
+Version 0.1.69 focuses on cloud execution:
 
 #### Planned Features
 - **Cloud Modal MVP** ([#982](https://github.com/massgen/MassGen/issues/982)): Run MassGen as a cloud job on Modal

ROADMAP.md

@@ -1,10 +1,10 @@
 # MassGen Roadmap
 
-**Current Version:** v0.1.67
+**Current Version:** v0.1.68
 
 **Release Schedule:** Mondays, Wednesdays, Fridays @ 9am PT
 
-**Last Updated:** March 23, 2026
+**Last Updated:** March 25, 2026
 
 This roadmap outlines MassGen's development priorities for upcoming releases. Each release focuses on specific capabilities with real-world use cases.
 
@@ -42,27 +42,27 @@ Want to contribute or collaborate on a specific track? Reach out to the track ow
 
 | Release | Target | Feature | Owner | Use Case |
 |---------|--------|---------|-------|----------|
-| **v0.1.68** | 03/25/26 | Cloud Modal MVP | @ncrispino | Run MassGen as a cloud job on Modal ([#982](https://github.com/massgen/MassGen/issues/982)) |
-| **v0.1.69** | 03/27/26 | OpenAI Audio API | @ncrispino | Support OpenAI audio API for audio understanding ([#960](https://github.com/massgen/MassGen/issues/960)) |
-| **v0.1.70** | 03/30/26 | Image/Video Edit Capabilities | @ncrispino | Check and support img/video editing capabilities ([#959](https://github.com/massgen/MassGen/issues/959)) |
+| **v0.1.69** | 03/27/26 | Cloud Modal MVP | @ncrispino | Run MassGen as a cloud job on Modal ([#982](https://github.com/massgen/MassGen/issues/982)) |
+| **v0.1.70** | 03/30/26 | OpenAI Audio API | @ncrispino | Support OpenAI audio API for audio understanding ([#960](https://github.com/massgen/MassGen/issues/960)) |
+| **v0.1.71** | 04/01/26 | Image/Video Edit Capabilities | @ncrispino | Check and support img/video editing capabilities ([#959](https://github.com/massgen/MassGen/issues/959)) |
 
 *All releases ship on MWF @ 9am PT when ready*
 
 ---
 
-## ✅ v0.1.67 - Modernized WebUI (Completed)
+## ✅ v0.1.68 - Checkpoint Mode (Completed)
 
-**Released:** March 23, 2026 | PRs: [#1016](https://github.com/massgen/MassGen/pull/1016), [#1013](https://github.com/massgen/MassGen/pull/1013)
+**Released:** March 25, 2026 | PRs: [#1028](https://github.com/massgen/MassGen/pull/1028), [#1025](https://github.com/massgen/MassGen/pull/1025), [#1024](https://github.com/massgen/MassGen/pull/1024)
 
 ### Features
-- **Modernized WebUI**: Complete UI redesign with inline final answers, keyboard shortcuts, and Zustand state management
-- **RoundBudgetGuardHook**: Per-round cost enforcement with configurable warning thresholds
-- **Unified Pre-Collab Phases**: Personas, evaluation criteria, and prompt improvement run in parallel
-- **Regression Guard**: Blind A/B verification subagent before submitting revisions
+- **Checkpoint Coordination Mode**: Delegator pattern — main agent plans solo then delegates to team via `checkpoint()` tool
+- **LLM API Circuit Breaker**: Automatic 429 rate limit handling with circuit breaker pattern for Claude backend
+- **WebUI Checkpoint Support**: Checkpoint mode display in the modernized WebUI
+- **LiteLLM Supply Chain Fix**: Pinned litellm<=1.82.6 and committed uv.lock
 
 ---
 
-## 📋 v0.1.68 - Cloud Modal MVP
+## 📋 v0.1.69 - Cloud Modal MVP
 
 ### Features
 
@@ -78,7 +78,7 @@ Want to contribute or collaborate on a specific track? Reach out to the track ow
 
 ---
 
-## 📋 v0.1.69 - OpenAI Audio API
+## 📋 v0.1.70 - OpenAI Audio API
 
 ### Features
 
@@ -94,7 +94,7 @@ Want to contribute or collaborate on a specific track? Reach out to the track ow
 
 ---
 
-## 📋 v0.1.70 - Image/Video Edit Capabilities
+## 📋 v0.1.71 - Image/Video Edit Capabilities
 
 ### Features