Arcjet

Arcjet puts an ALLOW or DENY decision in front of individual tool calls, so an agent's reach stops where your policy says it should. That's tool call authorization in plain terms. The guard() function and framework adapters cover custom agents, queue consumers, and agentic pipelines. It's the piece that separates "the agent can do this" from "the agent may do this."

Crafted input can push an agent into acting against its instructions, and Arcjet checks for that before the input drives a tool call. That's prompt injection defense at the boundary. This matters most where agents read text from outside your control, like user messages or fetched pages. Catching it here keeps a bad prompt from turning into a bad action.

Arcjet strips personal data from agent traffic as it moves through the system. Simple idea. If your agents handle customer records, payment details, or chat logs, redaction keeps that material out of places it shouldn't reach. It runs as part of the same protection pass, not as a separate cleanup step.

Before you enforce anything, Arcjet can show you what's already running. No code change needed. It ingests OpenTelemetry data or polls the Claude Compliance API to build a picture of the agents in your organization. Neither path enforces policy, so you get an accurate inventory first and decide what to lock down after.

Arcjet protects Claude Code and GitHub Copilot directly inside the development environment, using hooks those tools already fire. No SDK to install. No code to change. That makes this the fastest entry point if you want protection without touching a repository.

Server-side bot protection blocks automated abuse against websites and web apps, with client signals available as an optional second layer. Rate limiting, filters, and Shield WAF rules all count as a single web request. Good news for your bill, too.

Every enforced decision keeps the policy that ran and the values it read. When you need to answer "why did the agent do that," the record lets you reconstruct an answer instead of guessing. That's the difference between a log and an audit.

Arcjet ships an MCP server at https://api.arcjet.com/mcp, connected through OAuth. From your editor you can list teams and sites, create sites, pull site keys, inspect requests, explain decisions, check quota, analyze traffic, and investigate IPs. All without leaving your editor.