Circle Agent Stack MCP runs on your own machine — the client starts it, so there is no endpoint to ping. 39 installs a week from npm. Last commit 4 Jun 2026.
Circle Agent Stack for AI agents: USDC wallets, spend policies, transfers, and x402 nanopayments.
What the code does
We read the source, 5 d ago · rules 995398eba69f
What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.
ENV CIRCLE_API_KEY=dummy
Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.
This code can reach further than it looks
We found places where it runs commands, builds paths or queries from values it is given. None of that is a flaw by itself — it becomes one when the code changes, and code changes quietly between releases. We re-read it on every one.
Connect this server
This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.
claude mcp add circle-agent-stack-mcp -e 'CIRCLE_API_KEY=<CIRCLE_API_KEY>' -- npx -y circle-agent-stack-mcp{
"mcpServers": {
"circle-agent-stack-mcp": {
"command": "npx",
"args": [
"-y",
"circle-agent-stack-mcp"
],
"env": {
"CIRCLE_API_KEY": "<CIRCLE_API_KEY>"
}
}
}
}[mcp_servers.circle-agent-stack-mcp]
command = "npx"
args = ["-y", "circle-agent-stack-mcp"]
env = { CIRCLE_API_KEY = "<CIRCLE_API_KEY>" }{
"mcpServers": {
"circle-agent-stack-mcp": {
"command": "npx",
"args": [
"-y",
"circle-agent-stack-mcp"
],
"env": {
"CIRCLE_API_KEY": "<CIRCLE_API_KEY>"
}
}
}
}{
"servers": {
"circle-agent-stack-mcp": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"circle-agent-stack-mcp"
],
"env": {
"CIRCLE_API_KEY": "<CIRCLE_API_KEY>"
}
}
}
}Put your own value in place of
<CIRCLE_API_KEY> (Your Circle API key from developers.circle.com).
The author’s registry entry marks it as required.
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Circle Agent Stack MCP — questions
Answers built from our own checks of this server.