Keryx MCP Server

Autonomous research agent that pays every source it cites in USDC on Arc via x402 micropayments.

People who work with agentic payments, arc and circle and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-09-30 · ★ 2 · #139 OF 344 MAINTAINED FINANCE · VERIFIED 2026-09-30

TypeScript servers · how we verify → /methodology

01 · Install Keryx

before you install - you'll need

The README does not document required environment variables for a basic install.

Claude Code

claude mcp add tang-vu-keryx --transport http https://keryx.cc/mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "tang-vu-keryx": {
      "url": "https://keryx.cc/mcp"
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

https://keryx.cc/mcp

transport: streamable-http

endpoint alive - responded to MCP initialize · probed 2026-09-30

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions · remote - your agent's requests go to keryx.cc

endpoint auth accepted our unauthenticated MCP initialize - no credentials needed to connect

license no standard license detected - usage rights unclear; check the repo before commercial use

npm package keryx-mcp - unscoped; check the name against the project README before installing

registry namespace io.github.tang-vu is GitHub-verified and matches the repo owner

03 · What Keryx can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

v0.24.5 · 2026-09-30

add free public reference evidence catalog

v0.24.4 · 2026-09-30

use native Worker redirect refusal

v0.24.3 · 2026-09-30

attest Arc RPC at payment and indexer boundaries · pin browser signing to Arc testnet grant · add read-only release preflight · verify browser signature before callback acceptance · stage atomic browser authorization…

04 · Who maintains Keryx

keryx is maintained by tang-vu. It's the only MCP server we track from this author; the repo dates to Jun 2026.

05 · Facts

repository: github.com/tang-vu/keryx
website: https://keryx.cc/
category: finance - ranked #139 of 344 actively-maintained finance servers as of 2026-09-30.
release cadence: 10+ releases in the last 90 days (latest 2026-09-30)
registry: io.github.tang-vu/keryx (active, first published 2026-07-01 · 2 versions)
packages: npm:keryx-mcp

06 · Keryx FAQ

What is Keryx?

Autonomous research agent that pays every source it cites in USDC on Arc via x402 micropayments.

Is Keryx still maintained?

Yes - as of 2026-09-30, its last commit was 2026-09-30 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

How do I install Keryx?

Run `npx -y keryx-mcp`. The README does not document required environment variables for a basic install. You can also paste the ready-made client config above.

Does Keryx require authentication?

No - the endpoint accepted our unauthenticated MCP initialize when probed on 2026-09-30; you can connect without credentials.

07 · Alternatives to Keryx

Alternatives to Keryx

Maintained finance servers if Keryx isn't the fit.

Pairs well with

Servers that cover what Keryx doesn't - only shown when the pairing reason fits the companion.

More finance MCP servers · Tapetide - Indian Stock Market (NSE & BSE) · AkTools Pro MCP Server · Gold MCP · Form4API - SEC Insider Trading · Yookassa MCP

More TypeScript MCP servers · Datadog MCP · Taskade MCP · Plumb MCP · Sfcc Dev MCP · see all