agent-checkpoint

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Repo-local continuity skills for coding agents. Checkpoints use a shared agent-handoff/v1 markdown format so Codex/OpenAI CLI, Claude Code, opencode, and other programming agents can write and resume the same repo state.

These two skills turn "I lost the thread" into a recoverable workflow: save the real working lane into the repository itself, then restore it in the next session without depending on fragile external chat memory.

Demo

What It Does

• repo-checkpoint — writes a timestamped markdown handoff under .agents/checkpoints/, including session goal, current state, key chat context, files in play, verification state, next step, and a git snapshot.
• repo-resume — restores the latest active lane from the newest checkpoint plus current branch, working tree, and recent commits.

Why this exists: Most agents can reread code. What they usually lose is the human context: what the user actually wanted, what was already tried, which constraints mattered, and what the next concrete step should be.

Why It Matters

• Repo-local, not session-local — the handoff lives inside the repo, so it survives model switches, browser restarts, shell reconnects, and machine changes.
• Cross-agent by design — Codex can write a checkpoint and Claude Code or opencode can resume it later from the same .agents/checkpoints/ directory.
• Plain markdown, no lock-in — checkpoints are readable in any editor and reviewable in git.
• Fast cold start — resume goes straight to the last known lane instead of broad repo exploration.
• Human context included — goal, constraints, rejected paths, and next actions are captured explicitly.
• Works even without an agent runtime — both scripts can be run manually.

Best For

• long-running debugging or refactor sessions
• interruptions during implementation or review
• switching between local machine, remote box, and another agent session
• repos where "what were we actually doing?" is more expensive than reading the code

Quick Start

git clone https://github.com/hotalexnet/agent-checkpoint.git
cd agent-checkpoint
bash install-repo-skills.sh

Upgrade an existing install from GitHub:

bash <(curl -fsSL https://raw.githubusercontent.com/hotalexnet/agent-checkpoint/main/upgrade-repo-skills.sh)

From the target repo root:

# End of session: create a scaffold, then fill in the TODOs
python3 ~/.agents/skills/repo-checkpoint/scripts/save_checkpoint.py \
  --title "chat-routing-root-cause" \
  --agent codex

# Next session: recover the latest lane
python3 ~/.agents/skills/repo-resume/scripts/resume_snapshot.py

Example Flow

Session A:
- investigating a routing bug
- several files open
- one failed approach already ruled out
        ↓
repo-checkpoint
        ↓
.agents/checkpoints/20260513-114233-chat-routing-root-cause.md
        ↓
Session B starts later on the same or another machine
        ↓
repo-resume
        ↓
latest checkpoint + branch + working tree + recent commits
        ↓
continue from the real next step instead of re-deriving intent

What Gets Saved

Each checkpoint keeps these top-level sections:

• Agent Handoff
• Session Goal
• Current State
• Key Chat Context
• Files In Play
• Verification
• Next Step
• Resume Recipe
• Git Snapshot

That is the real value here: not just code state, but the reasoning state around the code.

Example Checkpoint Content

## Session Goal
- Fix the chat fallback so non-matching questions stop returning stale onboarding guidance.

## Current State
- Router fix is implemented locally.
- Local smoke test passed.
- Staging behavior still needs separate verification.

## Key Chat Context
- User wants root-cause-level cleanup, not a keyword patch.
- Old onboarding copy must stop leaking into normal chat replies.
- Do not broaden scope into model switching yet.

## Files In Play
- src/chat/router.py
- src/prompts/chat_prompt.py
- tests/test_chat_router.py

## Next Step
1. Reproduce against the current deploy path.
2. Verify fallback selection with 3 representative prompts.
3. Commit only after the bad greeting path is gone.

Install

Prerequisites

• python3
• git
• a skill runtime that loads skills from ~/.agents/skills, or a vendored skill path inside your own tooling

Option 1: Run the installer

bash install-repo-skills.sh

Default install target:

~/.agents/skills

Custom install target:

bash install-repo-skills.sh --target /path/to/skills

Option 2: Clone the repo

git clone https://github.com/hotalexnet/agent-checkpoint.git
cd agent-checkpoint
bash install-repo-skills.sh

Option 3: Copy the skill folders directly

mkdir -p ~/.agents/skills
cp -R repo-checkpoint ~/.agents/skills/
cp -R repo-resume ~/.agents/skills/

Usage

Trigger or need	Action
"save progress" / "checkpoint this"	run repo-checkpoint
"continue where we left off" / "what was I doing?"	run repo-resume
"show all checkpoints"	run repo-resume list
"clean up old checkpoints"	run repo-resume prune 5

Manual commands from the target repo root:

python3 ~/.agents/skills/repo-checkpoint/scripts/save_checkpoint.py --title "my-work"
python3 ~/.agents/skills/repo-checkpoint/scripts/save_checkpoint.py --title "my-work" --agent claude-code
python3 ~/.agents/skills/repo-resume/scripts/resume_snapshot.py
python3 ~/.agents/skills/repo-resume/scripts/resume_snapshot.py list
python3 ~/.agents/skills/repo-resume/scripts/resume_snapshot.py prune 5

Upgrade

From an existing clone:

cd agent-checkpoint
bash upgrade-repo-skills.sh

From any machine with Git, Bash, and Python:

bash <(curl -fsSL https://raw.githubusercontent.com/hotalexnet/agent-checkpoint/main/upgrade-repo-skills.sh)

Custom skill install directory:

bash upgrade-repo-skills.sh --target /path/to/skills

Use the current checkout without pulling, useful for testing local changes:

bash upgrade-repo-skills.sh --no-pull --target /path/to/skills

Recommended Workflow

1. Before closing a session

Run repo-checkpoint, then replace every TODO with concrete session state.

2. When reopening later

Run repo-resume first, before broad repo exploration.

3. Keep the checkpoint executable

A good checkpoint should answer these questions fast:

• What are we trying to finish?
• What is already true?
• What must not be broken?
• Which files matter first?
• What should happen next?

Why Repo-Local Beats External Chat Memory

• external session memory is often unavailable, partial, or tool-specific
• a repo-local handoff travels with the codebase
• teammates and future-you can inspect it without special software
• the checkpoint can be committed, ignored, copied, or archived with normal git habits

How It Works

Current coding session
    ↓
repo-checkpoint
    ↓
Timestamped markdown handoff under .agents/checkpoints/
    ↓
New session starts later
    ↓
repo-resume
    ↓
Latest checkpoint + current git state
    ↓
Continue the exact lane with minimal cold-start cost

Compatibility

• Any git repository
• Local machine or remote server
• Cross-machine reuse by cloning or copying the skill folders
• Manual CLI use, even if your agent runtime does not auto-load skills

Multi-Machine Usage

You can either:

• clone this repository on another machine and run the installer, or
• copy repo-checkpoint/ and repo-resume/ directly into that machine's ~/.agents/skills/

Updating

If you already installed an older version, rerun:

bash install-repo-skills.sh

The installer replaces:

• ~/.agents/skills/repo-checkpoint
• ~/.agents/skills/repo-resume

Limits

• Resume quality depends on checkpoint quality.
• The scaffold is intentionally simple; it does not auto-summarize your whole session for you.
• If you leave the TODOs blank, future-you still has to reconstruct intent.

.gitignore

Checkpoints are stored under .agents/checkpoints/. You can either commit them (so teammates can resume each other's work) or gitignore them (private notes):

# Option A: ignore all checkpoints
.agents/checkpoints/

# Option B: keep them in git — add nothing to .gitignore

Project Structure

agent-checkpoint/
├── README.md
├── README.zh-CN.md
├── CHANGELOG.md
├── VERSION
├── LICENSE
├── assets/
│   └── demo.gif
├── install-repo-skills.sh
├── repo-checkpoint/
│   ├── SKILL.md
│   └── scripts/
│       └── save_checkpoint.py
├── repo-resume/
│   ├── SKILL.md
│   └── scripts/
│       └── resume_snapshot.py
├── tests/
│   ├── conftest.py
│   ├── test_checkpoint.py
│   └── test_resume.py
└── scripts/
    └── generate_demo_gif.py

License

MIT License

Acknowledgments

• Repo-local continuity workflow patterns developed during long-running coding sessions
• Git, for making branch and working tree state easy to snapshot and recover

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⚠️ Note: Concrete files, constraints, verification state, and next actions are what make resume fast. The more specific your checkpoint is, the more valuable the next session becomes.