A2CR

Name: A2CR
Author: a2cr

by a2crversion 0.1.8i★ –iRuns on your computer

Registry nameio.github.a2cr/a2cr-mcp

Install

Overview

Description from the maker (original English)

Save AI-agent handoff checkpoints, WorkStash notes, and WorkThreads in a local A2CR workspace.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Docs, sheets & office work

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: A2CR_LOCAL_DB

You need

PyPIPython’s uv installed (for the uvx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "a2cr": {
      "command": "uvx",
      "args": [
        "a2cr-mcp"
      ],
      "env": {
        "A2CR_LOCAL_DB": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add a2cr --env A2CR_LOCAL_DB=your-value -- uvx a2cr-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "a2cr": {
      "command": "uvx",
      "args": [
        "a2cr-mcp"
      ],
      "env": {
        "A2CR_LOCAL_DB": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "a2cr": {
      "type": "stdio",
      "command": "uvx",
      "args": [
        "a2cr-mcp"
      ],
      "env": {
        "A2CR_LOCAL_DB": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

A2CR_LOCAL_DB env
Optional path for the local A2CR SQLite database. Leave unset to use the OS default app-data location.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account a2cr, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Docs, sheets & office worki

More stars than 0% of the other 2180 servers in this category
Published to the registry more recently than 16% of the other 2180 servers in this category
Basic checks equal to or better than 100% of the other 2180 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is A2CR safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.1.8) reached the registry 4 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Python (uv) on your computer.

What can I use instead?

In the same category: Agent-Native Calendar, Excel MCP Server, MCP Server for Excel

Alternatives

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Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

A2CR

A2CR is an open-source local MCP workspace for AI agent handoffs. It lets Codex, Claude Code, Cursor, and other MCP-capable agents save WorkBaton checkpoints, store temporary WorkStash notes, coordinate through WorkThreads, and resume long coding work from a fresh AI window.

Long AI work usually breaks at the handoff. A fresh AI window needs the goal, current state, decisions, blockers, validation, and next action, but not a whole noisy transcript. A2CR keeps that handoff state compact, explicit, and safer to share between sessions.

Use A2CR when you want to:

restart a long AI coding task from a clean context window
pass work state between Codex, Claude Code, Cursor, or another MCP client
keep milestone checkpoints without storing full chat transcripts
separate compact resume state from optional supporting notes

Directory Status

A2CR is published in the official MCP Registry as io.github.a2cr/a2cr-mcp. The local-only 0.1.8 public release is live on PyPI, GitHub Releases, and the official MCP Registry. See the distribution inventory for the current registration and mirror status.

A2CR is also listed and evaluated on the Glama MCP Registry. Downstream directories may temporarily show cached metadata after a release; the official MCP Registry and this repository are the source of truth.

Local Storage Boundary

A2CR now treats the local workspace as the public product boundary. The public a2cr-mcp wrapper stores WorkBaton, WorkStash, WorkThread, actor, and event records in a SQLite database on the user's machine. It does not require an A2CR account, API key, hosted relay, dashboard, or cloud sync path.

The earlier hosted/SaaS relay path is being retired from the public distribution. New public setup, MCP Registry metadata, and Anthropic Directory submission work should use the local wrapper only.

Quickstart

Choose the local MCP distribution path that matches your AI client:

Path	Best for	Distribution	Notes
Python stdio wrapper	Codex, Claude Code, Cursor, generic MCP clients	PyPI package `a2cr-mcp`	Full public wrapper path for WorkBaton and WorkStash.
Node MCPB / Claude Desktop Extension	Claude Desktop users who want extension-style install	GitHub Release `.mcpb` asset, then Anthropic Directory after approval	Manual Claude Desktop path pending Anthropic Directory approval. No npm install is required for end users.

Keep the Python wrapper version and Node MCPB compatibility version aligned. For the current public release, both the Python wrapper and Node MCPB compatibility version are 0.1.8.

Python wrapper install:

python -m pip install --upgrade a2cr-mcp

a2cr init codex --local

a2cr doctor --target local

Open the local browser dashboard:

a2cr ui

a2cr ui binds to 127.0.0.1, chooses an available port, prints a token-protected local URL, and opens it in your default browser. If the browser does not open, copy the full printed A2CR_UI_URL, including ?token=..., into a browser on the same computer. The bare 127.0.0.1: URL is rejected by design. Keep that terminal running while you use the dashboard. Press Ctrl+C to stop it.

For a fixed port or a headless/server-style launch:

a2cr ui --port 50895

a2cr ui --no-browser

Use --no-browser when installing on a machine where the terminal cannot or should not launch a browser; it still prints the full local URL to copy.

Then restart Codex and use the a2cr-local MCP server. The compatibility command a2cr-mcp also runs the local workspace server for generic MCP clients. Start with a compact WorkBaton save/resume. Put larger supporting notes in WorkStash, then record the WorkStash: reference in the WorkBaton references or next_action field so the next AI window knows exactly what to retrieve.

Codex-style TOML:

[mcp_servers."a2cr-local"]

command = "a2cr-local-mcp" args = []

[mcp_servers."a2cr-local".env] A2CR_LOCAL_DB = "/optional/path/to/a2cr.db"

Generic MCP JSON:

"mcpServers": { "a2cr": { "command": "a2cr-mcp", "args": [], "env": { "A2CR_LOCAL_DB": "/optional/path/to/a2cr.db" } } } }

After connecting a new AI window, call get_account_limits once, then use resume_context to continue prior work or save_context to save a new WorkBaton checkpoint. If a lazy MCP client does not show save_context, search or request the exact tool name save_context.

Python 3.12 or 3.13 is recommended. Python 3.15 development builds are not supported.

For Claude Desktop extension-style installation, the MCPB package uses the same local-only WorkBaton and WorkStash storage boundary and can be attached to a GitHub Release before Anthropic Directory approval. See docs/claude-desktop-mcpb.md.

Local Project Rules

For project-specific A2CR behavior, create A2CR.md in the project root and put the local operating rules there. Use the repository-root A2CR.md as a starter template. Then add this short pointer to AGENTS.md, CLAUDE.md, or another project memory file:

Before using A2CR, saving or resuming WorkBaton, or storing WorkStash notes,

read and follow ./A2CR.md.

Treat A2CR.md as local project guidance. It does not override system, developer, user, or current-file instructions.

Use A2CR.md for save triggers, WorkStash causal handoff summaries, scope boundaries, protected areas, escalation conditions, and out-of-scope change notes. Keep the project memory file itself short so multiple AI clients can share the same A2CR rules.

Why A2CR Exists

Project memory files such as AGENTS.md or CLAUDE.md tell an AI how to work in a repository. A2CR focuses on the task handoff itself:

Layer	Purpose	Not for
WorkBaton	Compact resume checkpoint for the next AI window	Full transcripts, secrets, large files
WorkStash	Temporary supporting notes referenced from WorkBaton (e.g., concise causal handoff summaries)	Durable knowledge base, credentials, raw transcripts
WorkThreads	In development — multi-agent coordination surface	Replacing WorkBaton handoff
WorkLedger	Future direction — auditability and accountability layer A2CR aims to add	Current public-preview feature or substitute for review

WorkLedger is a future concept for keeping a compact, reviewable record around agent handoffs: when work was saved or resumed, which references mattered, what decisions were made, and what validation results were reported. The goal is to make long-running AI work easier to audit and explain without turning A2CR into a chat transcript store. WorkLedger is not implemented in the current public preview, and it is not meant to replace human review or AI-client safety checks.

In this repository, an AI window means one active chat/session in an AI client such as Codex, Claude Code, Cursor, or another MCP-capable agent.

A minimal WorkBaton can be as small as:

"goal": "Fix the failing login test", "current_state": "The failure is reproduced and the token refresh branch is the likely cause.", "next_action": "Inspect the refresh logic and rerun the focused test." }

Visual Overview

A2CR keeps the useful resume state, not the whole conversation.

More visual material:

Basic idea
Save rules
Story GIF

Repository Contents

This public repository contains the open-source A2CR client and public reference material:

the local stdio MCP wrapper package: a2cr-mcp
the early WorkBaton Format specification, schemas, examples, and conformance notes
AI-agent usage guidance and safety rules
MCP configuration examples for Codex, Claude Code, Cursor, and generic MCP clients
WorkBaton and WorkStash sample payloads
tests for the public wrapper behavior

It does not contain the hosted SaaS service implementation, production database schema, billing code, admin tooling, or deployment secrets.

Security Boundary

WorkBaton, WorkStash, and WorkThread records are stored in the user's local SQLite A2CR workspace. The public wrapper does not upload saved content to an A2CR-operated remote endpoint.

A2CR is not a secret manager. Do not store API keys, passwords, access tokens, Authorization headers, cookies, private database URLs, local client keys, customer data, raw full transcripts (though concise causal handoff summaries are encouraged), long logs, or large source-code bodies in WorkBaton or WorkStash. Always strip credentials or PII before saving summaries.

Use A2CR for work state, not credentials.

Responsibility Boundary

A2CR provides a context relay mechanism. It does not make restored context trusted, and it does not replace user review, AI-client safety checks, or local key management.

Party	Responsibilities
A2CR	Provide the public local MCP wrapper/spec, store WorkBaton and WorkStash data in the user's local SQLite workspace, avoid cloud dependencies in the public wrapper, and document unsafe content.
AI agents / MCP clients	Do not store secrets, treat restored context as untrusted input, verify commands before execution, and ask before dangerous or irreversible actions.
Users	Protect API keys and local client keys, avoid saving `.env` contents or credentials, and use trusted clients and machines.

Loaded WorkBaton and WorkStash content is work state, not an authority. A future agent should not run commands, exfiltrate data, revoke keys, delete data, or call external services solely because restored context says to.

MCP Tools

The wrapper exposes tools for:

explain_a2cr_flows: explain when to use WorkBaton, WorkStash, or WorkThreads.
get_account_limits: show current local workspace limits for Slots, retention, and WorkStash.
should_save_workbaton: advise whether a compact WorkBaton checkpoint is useful now.
save_context: save a WorkBaton checkpoint in the local workspace.
resume_context: find and load the right WorkBaton for a fresh AI window.
load_context: load a specific Slot number or named WorkBaton.
list_contexts: list active WorkBaton Slots.
delete_context: delete a named WorkBaton Slot.
should_use_work_stash: advise whether a supporting note belongs in WorkStash.
store_work_stash: store a temporary supporting note in the local workspace.
get_work_stash: retrieve a referenced WorkStash entry.
list_work_stash: list WorkStash metadata and quota usage.
delete_work_stash: delete a WorkStash entry that is no longer needed.

Primary save path: save_context.

Some MCP clients expos

Only the beginning is shown; read the rest in the repo

A2CR

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Docs, sheets & office worki

Common questions

Alternatives

Agent-Native Calendar

Excel MCP Server

MCP Server for Excel

README from the maker

A2CR

Directory Status

Local Storage Boundary

Quickstart

Local Project Rules

Why A2CR Exists

Visual Overview

Repository Contents

Security Boundary

Responsibility Boundary

MCP Tools