list_contextsLABSCO SUMMARY
Agents that can read each other's history
Three tools and a filter set are enough for the question this exists to answer: what was done, where, and by which agent. The filters — project path, machine, source, time range — are what turn the answer into a specific session rather than a summary of everything.
What it is
UltraContext's MCP server over the Context API. It gives any MCP-compatible agent access to sessions other agents have already had, whether the CLI ingested them or an SDK wrote them.
What you get
- list_contexts — recent contexts, filtered by source, user, host, project path, session id, or a time window
- get_context_messages — every message in one context, fetched by its public id
- get_recent_activity — the 'what happened last?' shortcut, taking the latest context and returning its most recent messages
- Sessions from claude, codex and openclaw sitting in the same store
Requirements
Node.js 22 or newer, and a Context API key in ~/.ultracontext/config.json — the same file the CLI writes, which the MCP server reads by itself. The CLI has to be running for sessions to be ingested. There is a hosted route as well: any Streamable HTTP client can talk to https://api.ultracontext.ai/mcp with the same Bearer token the REST API uses, and the standalone HTTP transport listens on port 3100 unless MCP_PORT says otherwise.
Setup effort
Follow the published steps — npm install -g ultracontext
USE CASES
01
Picking up where another agent stopped
Ask what Codex did last and get its most recent context back, so the next agent starts from the actual messages rather than from your recollection of them.
02
Finding the session that touched this repo
Filter by project path and time window to pull the sessions that ran against one directory, then open the one you want in full.
03
Reviewing a day's work across machines
Filter by host and an ISO timestamp range to list what ran where, which is how you reconstruct a day spread across more than one computer.
3 tools
Listed in project docs. Your client may show a different list.
get_context_messagesget_recent_activityBEFORE YOU INSTALL
What to know first
Tools you get
3 tools named in the project's documentation.
Requires
- Node.js 22 or newer
- pnpm on PATH
Where it runs
Both documented clients run the server on your machine.
INSTALLATION
Connect your client
Server setup
Setup
TERMINAL
npm install -g ultracontext
ultracontext config
git clone https://github.com/ultracontext/ultracontext.git
cd ultracontext
pnpm installHosted endpoint
ENDPOINT URL
https://api.ultracontext.ai/mcpAdd this hosted endpoint to your MCP client using the credentials listed under Requirements.
MCP Clients
Claude Code
CLAUDE CODE · TERMINAL
claude mcp add ultracontext -- npx tsx <YOUR_PATH_TO_ULTRACONTEXT>/apps/mcp-server/src/stdio.tsCodex
CODEX · TOML
[mcp_servers.ultracontext]
command = "npx"
args = ["tsx", "<YOUR_PATH_TO_ULTRACONTEXT>/apps/mcp-server/src/stdio.ts"]
