Attest proxy

Attest proxy runs locally from a Python package published to PyPI: attestlayer version 0.1.0. It speaks MCP over stdio, so the client starts it as a program and talks to it through standard input and output. It needs Python; clients usually start it with uvx (from uv) or after pip install — the usual command is uvx attestlayer. It reads these environment variables: ATTEST_POLICY, ATTEST_LEDGER, ATTEST_INBOX_URL, SLACK_BOT_TOKEN (secret) and ATTEST_SLACK_CHANNEL; set them in the client's configuration for this server. Required arguments: --upstream.

In the mcpServers JSON format that many desktop and editor MCP clients read, the entry looks like this (placeholders in angle brackets):

{
  "mcpServers": {
    "attest-proxy": {
      "command": "uvx",
      "args": [
        "attestlayer"
      ],
      "env": {
        "ATTEST_POLICY": "<value>",
        "ATTEST_LEDGER": "<value>",
        "ATTEST_INBOX_URL": "<value>",
        "SLACK_BOT_TOKEN": "<secret>",
        "ATTEST_SLACK_CHANNEL": "<value>"
      }
    }
  }
}

Derived from the registry entry, not tested here. What the server does, and on what terms, is set by its publisher; check its repository or website before giving it access to your accounts or files. How to add an MCP server to an assistant · Before you connect