Fastn vs Preloop - Managed Gateway or the MCP Firewall?
Giving AI agents the power to call tools is high-risk. Fastn provides a managed gateway for orchestrating connections at scale, while Preloop acts as a "Safety Layer" or a firewall for MCP, focusing on policy-driven approvals and human-in-the-loop safety. This guide compares their different roles in a production agent stack.
Feature Comparison: Fastn vs Preloop
1. Functional Roles
- Fastn is a Managed MCP Gateway. Its primary job is to unify over 1,000 integrations into a single, efficient MCP server. It handles the connectivity, authentication, and context optimization (Adaptive Context Layer) for high-scale agentic workflows.
- Preloop is an MCP Firewall. It sits in front of existing tools to decide whether actions are allowed, blocked, or require human intervention. It provides a policy engine that adds a security layer to any MCP server without requiring code changes.
2. Security and Governance
- Fastn focus on Enterprise Governance. It is built on a foundation that is SOC 2 Type II, ISO, and GDPR-ready. It provides built-in RBAC, compliance policy enforcement, and managed OAuth/API key management.
- Preloop focus on Dynamic Safety Policies. It uses "Policy-as-Code" (via CEL) to define fine-grained access rules at the parameter level. It features "Human-in-the-Loop Approvals," where sensitive operations can be routed for approval through Slack, Teams, or mobile.
3. Capabilities and Observability
- Fastn provides Telemetry and Visibility into tool usage, costs, and agent reasoning paths, ensuring that developers understand how their tools are performing at scale.
- Preloop provides a Full Audit Trail. It logs every tool call with the full context, including agent-provided justifications for the actions. It also supports "Event-Driven Automation," allowing for automated actions based on external events across various tools.
Comparison Table: Fastn vs Preloop
| Feature | Fastn | Preloop | HasMCP |
|---|---|---|---|
| Primary Goal | Managed Action Gateway | MCP Safety Layer & Firewall | No-Code API Bridge |
| Integrations | 1,000+ Unified Connectors | Connects to any existing MCP | Any OpenAPI Spec + Hub |
| Safety Tech | Compliance-Ready Policy | Policy-as-Code (CEL) | Encrypted Vault & Proxy |
| Approvals | Standard RBAC | Human-in-the-loop (Slack/etc) | Native OAuth2 Elicitation |
| Key Offering | Adaptive Context Layer (UCL) | parameter-based Policy Engine | Automated OpenAPI Mapping |
| Deployment | Managed High-Scale Cloud | Policy SaaS / Integrated | Managed Cloud & Self-Host |
The HasMCP Advantage
While Fastn excels at scaling the gateway and Preloop masters the safety firewall, HasMCP provides the automation-first bridge that turns your proprietary APIs into efficient agents with built-in, granular control.
Here is why HasMCP is the winner for API-centric teams balancing speed and safety:
- Zero-Code API Transformation: Preloop focuses on *protecting* existing tools. HasMCP actually *builds* them by instantly transforming any OpenAPI or Swagger definition into a fully functional MCP server. This is the fastest way to bridge your internal APIs.
- Native Context Optimization: HasMCP uses high-speed JMESPath filters and Goja-powered JavaScript Interceptors to sanitize data and reduce token usage by up to 90%. This ensures that your agent remains accurate and costs stay low.
- Dynamic Tool Discovery: HasMCP's "Wrapper Pattern" fetches full tool schemas only on-demand. This reduces initial token overhead by up to 95%, allowing you to expose massive numbers of tools while staying within the agent's context limits.
- Self-Host Community Edition (OSS): For teams that prioritize data privacy, HasMCP offers an open-source community edition. This gives you the power of an automated MCP bridge with full control over your data residency—something that complements or even replaces the need for external policy engines.
FAQ
Q: Does Fastn support human-in-the-loop approvals?
A: Fastn provides governance and RBAC, but it is not as specialized as Preloop for routing individual tool calls for manual human approval in real-time.
Q: Can I use Preloop with any MCP server?
A: Yes, Preloop is designed to sit in front of any MCP-compatible agent or IDE, including Cursor, Claude Code, and various custom implementations.
Q: How does HasMCP handle security?
A: HasMCP includes an encrypted vault for secret management and detailed audit logs for visibility. It also supports native OAuth2 elicitation to keep user credentials out of the LLM context.
Q: Which tool is better for preventing unauthorized file access?
A: Preloop’s parameter-based policy engine is specifically built for this level of granular control, allowing you to intercept and block actions based on specific file paths or commands.