Cairn.ink Memory

Name: Cairn.ink Memory
Author: Cairn-ink

by Cairn-inkversion 0.1.0i★ –iRuns in the cloud

Registry nameink.cairn/memory

Install

Overview

Description from the maker (original English)

Cross-session memory for AI agents with a Source Receipt for every memory, over MCP.

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 in the cloud
Transport: Streamable HTTP
Category: Search & AI memory
You need to fill in: Authorization

Install

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

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: Authorization

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Runs in the cloudNothing to install; it connects over the internet

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

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

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Run this in your terminal

claude mcp add --transport http memory https://cairn.ink/api/mcp --header 'Authorization: your-value'

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": {
    "memory": {
      "url": "https://cairn.ink/api/mcp",
      "headers": {
        "Authorization": "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": {
    "memory": {
      "type": "http",
      "url": "https://cairn.ink/api/mcp",
      "headers": {
        "Authorization": "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 address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

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

Values you fill in

Authorization secret HTTP header
Optional. Bearer from https://cairn.ink/settings/tokens. Clients that support OAuth discover authentication automatically and can omit this header.

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

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

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 against the domain cairn.ink (the registry checks domain ownership)
… 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 checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Search & AI memoryi

More stars than 0% of the other 7243 servers in this category
Published to the registry more recently than 48% of the other 7243 servers in this category
Basic checks equal to or better than 100% of the other 7243 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 Cairn.ink Memory 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?

You need to fill in: Authorization

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.1.0) reached the registry 42 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

by upstash

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

Computer or cloud★ 64,224MITUpdated 3 days ago

Install

Codebase Memory

by DeusData

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

Runs on your computer★ 48,148MITUpdated 20 days ago

Install

Exa

by exa-labs

Connect AI agents to Exa for web search, content fetching, and multi-step research.

Runs in the cloud★ 5,213MITUpdated 44 days ago

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.

Cairn Memory

Keep important context between AI sessions. Change it when things change.

English · 繁體中文

See an example · Where to start · Local setup · Hosted setup · Limitations · Privacy

Cairn Memory is Cairn.ink's open-source AI memory toolkit for Claude Code and Codex, with local MCP tools or cloud automatic memory. Visit Cairn.ink, install @cairn-ink/memory on npm, or view the Cairn Memory GitHub repository.

Starting a new AI session often means repeating your preferences and project decisions. Cairn provides memory tools to save that context between sessions, inspect the submitted text behind each memory, and update it when things change.

A preference changes

Suppose you save “Keep my reports short.” Later, you decide you need detailed reports. You can inspect the old memory and its source text, correct the saved preference, or forget it so it is no longer available for active recall.

This is an illustrated explicit-tool example, not a chat-client screenshot. The local preview uses tools to save, inspect, correct and forget; it does not automatically read your conversations.

Inspect the source. Read the source text stored with a memory. A receipt does not prove that the memory is true or correctly interpreted.
Correct what changed. Update the memory at the revision you inspected.
Forget what should go. Remove a memory from active recall. Deletion and backup boundaries apply.

A Source Receipt is the submitted text attached to a memory. It helps you check what was supplied when the memory was saved or corrected. It is not a verified transcript of the whole conversation or proof of human intent.

Cairn Memory and Cairn

Cairn Memory is the open-source toolkit in this repository for saving, inspecting and changing AI memory. [Cairn](https://cairn.ink) is the hosted shared memory map for people and AI, where people organize, review and share knowledge.

This repository includes local memory tools and connectors to the hosted Cairn service. Each path has its own setup and feature boundaries. Local use does not require a Cairn account; hosted connections require a compatible service and authentication.

Choose your starting point

You want to…	Start here	What you need
Understand the idea before installing	繁體中文 or the recorded walkthrough	No installation or account
Try the open-source tools on your computer	Local preview setup or Windows guide	Terminal setup; Linux x64 and a bounded native Windows x64 check; no Cairn account
Use the documented hosted Claude Code or Codex connection	Hosted setup	A compatible hosted service and authentication; separate from local-preview client support
Build on the memory layer	Architecture and MCP tools	JavaScript or MCP integration work

If you use Claude or Codex but do not usually install tools from a terminal, start with the example and recorded walkthrough. This preview requires setup; check the tested client paths before connecting your AI tool.

Current preview

Cairn's open-source memory layer stores memories in your own SQLite file and exposes them through MCP or JavaScript. No Cairn account is needed for local use.

Developer preview. Installed persistence and a narrow real-model memory loop have retained evidence. Default extraction still fails our source-support bar; see known limitations. Save, inspect, correct and forget work without a model key. Semantic recall requires your OpenAI key and sends selected context to that provider.

Watch the recorded walkthrough

Watch the 36-second model-free demo (MP4). This records the memory tools running, rather than a conversation in Claude or Codex. “Model-free” means no AI model is called during the walkthrough.

For long-conversation results, see the four-case real-model pilot. It is an opt-in diagnostic with one failed Cairn answer, not a measurement of long-term default-client recall reliability. Known limitations

Open the recorded tool walkthrough (GIF)

The demo below records the model-free loop: save, restart, inspect, correct and forget. Its recall step reports model_not_configured.

Recorded responses and regeneration instructions · Verified capabilities and client support

Install

For Claude Code and Codex, run the one-command installer:

npx @cairn-ink/memory setup

A fresh interactive install asks once: local MCP memory tools on this computer, or cloud automatic memory with cairn.ink sign-in; choose directly with setup --local or setup --cloud. Fresh non-interactive runs need --local or --cloud; local mode has no automatic capture or recall in 0.6.3.

Installer 0.6.3, with Codex 0.164.0–0.166.0 format requalification, was published on 2026-11-03, so npx @cairn-ink/memory setup uses it; a checkout can also run node packages/setup/bin/memory.mjs setup. The plugin is 0.3.3. Requires Node ≥22.16 and at least one CLI on PATH. Cloud setup asks about new tools, updates connected tools, and uses one browser sign-in when connecting both. The default server is cairn.ink. Conflicting servers or memory IDs present a choice; non-interactive conflicts change nothing. Codex must pass format qualification before automatic memory is enabled. Automated codex exec runs skip capture and prompt recall by default; opt in with npx @cairn-ink/memory config --codex-capture-exec on.

Choose the mode that fits your workflow:

[Local preview](#try-the-local-memory-layer): your SQLite database, explicit MCP memory tools, no Cairn account. Start here to try the open-source memory layer. Semantic recall uses your OpenAI key.
[Hosted integration](#existing-hosted-integration): memory on cairn.ink, with automatic capture and recall through the Claude Code plugin. Requires a Cairn account, token and compatible service. Explicit hosted MCP is also available.

Try the local memory layer

Prerequisites: Git, Node >=22.16, npm and `tar`. Recorded checks cover Linux x64 and a bounded native Windows x64 installation. On Windows, use the [PowerShell setup and walkthrough](docs/windows-install.md); the commands below use Linux/WSL paths. Other platforms are unverified. Install from this repository: the unscoped npm and PyPI packages named cairn-memory are unrelated projects. The local archive is not published to npm yet.

1. Install into a new directory. Replace the path below with a new absolute directory beneath an existing parent you control.

git clone https://github.com/Cairn-ink/cairn-memory.git

cd cairn-memory npm run install:preview -- --directory /absolute/new/cairn-local --owner local-user

The installer builds this checkout and downloads pinned public npm dependencies without install scripts. It creates app/, data/ and a private installation-receipt.json containing the executable path and MCP settings. It makes no model calls. Keep the receipt private: it contains local paths and identity. Installation details, recovery and backup

2. Run the model-free check. From the source checkout, use the same installation path. No chat-client setup or model key is needed.

npm ci --prefix adapters/mcp

node adapters/mcp/walkthrough.mjs --executable /absolute/new/cairn-local/app/node_modules/.bin/cairn-memory

Expect status: "passed". The check uses a fresh synthetic database and verifies the five tools, receipts, process-restart persistence, correction and forgetting. It strips the model key from the child process; model_not_configured is the expected recall result. Steps and expected results

3. Connect a client. Copy stdio.command and stdio.args from your private installation receipt into the client's local MCP configuration. Keep the same database, owner and project across sessions. See the tested client matrix.

For semantic recall, explicitly supply OPENAI_API_KEY through the MCP process's secret environment. The walkthrough's optional --with-recall path sends synthetic context to OpenAI and incurs model charges; it has no built-in dollar cap. A fully local model path is not yet verified.

For the Hermes native provider, follow its separate setup guide. It uses a profile-local database and owner, plus CAIRN_MEMORY_OPENAI_API_KEY, rather than the generic MCP settings above.

Tool	Purpose
`remember_memory`	Explicitly save one memory and its receipt
`recall_memory`	Model-guided retrieval of current memories and receipts
`inspect_memory`	List memories, or inspect an ID, revision and receipts
`correct_memory`	Replace content at the revision you inspected
`forget_memory`	Logically delete at the revision you inspected

The default local server exposes explicit tools. For opt-in submitted-message capture, project scope and configuration checks, see the installed preview guide. The full evidence and limitations cover extraction failures, long-history retrieval and the boundaries of individual client tests.

Local privacy and control

Memory, receipts and organization persist in your selected SQLite database. No Cairn account, hosted service or hidden core telemetry is required.
MCP does not read transcripts or save whole conversations automatically. Receipt text records a tool assertion; it is not proof of authenticated human intent.
Model processing is cloud processing when configured. Redaction is best-effort, not a guarantee that all secrets are removed. Retrieved text is untrusted data, never instructions to follow.
Forgetting prevents active recall and exact normalized re-admission; paraphrases can still be

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

Cairn.ink Memory

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 Search & AI memoryi

Common questions

Alternatives

Context7

Codebase Memory

Exa

README from the maker

A preference changes

Cairn Memory and Cairn

Choose your starting point

Current preview

Watch the recorded walkthrough

Install

Try the local memory layer

Local privacy and control