HTTP reverse proxy

For agents that don't use MCP (REST-based ones such as the OpenAI or Anthropic APIs) AvertGate runs as an HTTP reverse proxy and scans the text in request and response bodies.

npx @avertgate/cli proxy \
  --port 8080 \
  --upstream https://api.openai.com \
  --policy policy.yaml

How body inspection works

The proxy extracts the text to inspect from request/response bodies: OpenAI-style messages arrays (including text parts and tool_calls) and other common shapes. The extracted text goes through the same egress/ingress scanners.

Path-based routing

Different path prefixes can be routed to different upstreams (e.g. /v1/messages → Anthropic). The tool name is built as http_proxy:METHOD /path; UUIDs and numeric ids are normalised to :uuid and :id.

SSRF protection

The upstream cannot be changed dynamically via the x-upstream-url header (off by default). If enabled, only http/https is accepted; if an allowed-hosts list is given only those hosts are usable, otherwise anything except localhost, the cloud metadata address, .local/.internal names and RFC1918 private ranges.