AI agents invoke add_interception_rule to trigger actions in Mitmproxy. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
Adding an interception rule to a proxy like mitmproxy causes active modification of network traffic as it flows through. This is an Execute-level action — it configures runtime behavior that intercepts and potentially modifies live HTTP/HTTPS requests and responses.
From the tool's definition Tool name 'add_interception_rule' on a server that 'inspect, modify, and replay HTTP/HTTPS traffic in real-time'
Documented attack patterns abuse exactly the kind of access add_interception_rule gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mitmproxy, and nothing reaches the server without passing your rules. This is the rule we recommend for add_interception_rule:
{
"version": "1",
"default": "deny",
"tools": {
"add_interception_rule": {
"limits": [
{
"counter": "add_interception_rule_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}add_interception_rule stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
add_interception_rule. It is categorised as a Execute tool in the Mitmproxy MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Mitmproxy MCP server in PolicyLayer and add a rule for add_interception_rule: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Mitmproxy. Nothing to install.
add_interception_rule is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the add_interception_rule rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for add_interception_rule. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
add_interception_rule is provided by the Mitmproxy MCP server (snapspecter/mitmproxy-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 25 Mitmproxy tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
25 Mitmproxy tools catalogued and risk-classified — across an index of 42,500+ MCP servers.