sepiace

Long-term memory for AI agents. Your agent passes one natural-language sentence, and sepiace remembers, recalls, or forgets.

_{If sepiace helps you, a star keeps us going.}

Important

sepiace is in beta. Memories are stored on the sepiace server at hi.sepiace.io, separately for each account. Do not ask your agent to remember passwords, API keys, or other secrets.

Quick start

npm create sepiace

It finds Claude Code, Codex, Cursor, VS Code, and OpenCode on your machine, connects the ones you choose, and walks you through signing in. Then start a new session and ask your agent:

• "Remember that I prefer pnpm over npm."
• "What did we decide about the release schedule?"
• "Forget my old home address."

To bring over what your agent already remembers, run /sepiace:migrate in Claude Code, or ask other clients to use the sepiace-migrate skill. It shows you what it found and sends nothing until you agree.

Install by hand

Claude Code:

/plugin marketplace add osaxyz/sepiace
/plugin install sepiace@sepiace

Codex:

codex plugin marketplace add osaxyz/sepiace
codex plugin add sepiace@sepiace
codex mcp login sepiace

Other MCP clients: add https://hi.sepiace.io/api/v1/mcp as a remote MCP server (Streamable HTTP). The client signs in through OAuth in the browser.

Technology

One sentence in, memory text out

Your agent writes what it wants in plain words. A judgment network on the server decides whether to save, recall, search, or forget, and combines them when needed. The response contains only memory text, with no IDs, dates, or scores, so the agent spends no tokens building structured arguments.

Memories are your own words

Each memory is cut from the sentences in the request. No LLM writes or rewrites it, and when something becomes outdated, only that sentence is replaced. A memory stays in the language you wrote it in.

Memories fade unless they are used

Each memory's score follows the FSRS forgetting curve and is computed when it is read. Memories that go unused fade, and once a memory's recall probability drops below 50%, it no longer appears in search. Each recall makes it stick.

Your memories stay yours, and you can see every request

Memories are kept separately for each account, and every database query and vector search is scoped to the signed-in user. The console at hi.sepiace.io lists every request with the memories it changed, and a client you disconnect there stops working right away.

Measured with KiokuBench

KiokuBench checks what a memory system actually stored: whether it kept the facts, replaced outdated ones, forgot what it was asked to forget, and stayed tidy. The KiokuBench Index combines these four pillars into one number from 0 to 100.

System	Index	Remember	Replace	Forget	Tidy
sepiace	96.1	98.7	98.0	100.0	88.2
Supermemory	58.9	95.3	95.0	22.0	60.5
ByteRover	39.2	72.3	19.0	62.0	27.7
Mem0	8.5	96.3	0.0	0.0	55.0
Store everything	8.0	99.0	0.0	0.0	41.7

KiokuBench v0.1, 10 personas in English and Japanese, raw conversation passed in as is. sepiace was measured on October 14, 2026, and the others between September 27 and 30, 2026. KiokuBench was designed and run by the team that builds sepiace. The method, the eight metrics, the conditions for each system, and the limitations are on sepiace.io.

Specification

Plugin components

Component	What it does
MCP server	Connects https://hi.sepiace.io/api/v1/mcp. It has one tool, memory, which takes one sentence
memory skill	Tells the agent to recall before acting, to save durable facts as plain sentences about you, and never to send secrets
Session-start note	A short reminder, about 130 tokens, added when a session starts, is cleared, or is compacted
migrate skill	Moves local memories into sepiace. It runs only when you ask for it
update skill	Updates the plugin and the skills in every client to the latest version. It runs only when you ask for it

What the migrate skill reads

Source	Files
Claude Code auto memory	~/.claude/projects/*/memory/*.md
Claude Code user instructions	~/.claude/CLAUDE.md
Codex memories	~/.codex/memories/
Codex user instructions	~/.codex/AGENTS.md

It never changes the local files.

What npm create sepiace changes

Client	What it does
Claude Code, Codex	Installs the plugin from this repository
Cursor	Adds sepiace to ~/.cursor/mcp.json and the skills to ~/.cursor/skills
VS Code	Adds sepiace to the user mcp.json and the skills to ~/.copilot/skills
OpenCode	Adds sepiace to ~/.config/opencode/opencode.json and the skills to ~/.config/opencode/skills
Claude Desktop and claude.ai	Shows how to add sepiace as a custom connector

The CLI lives in cli/ and is published to npm as create-sepiace.