Secure Web Proxy helps secure your outbound agentic traffic and standard web
traffic---HTTP and HTTPS---from your organization's internal network.
When you configure your AI agents and non-agentic workloads to use
Secure Web Proxy as a gateway, the proxy acts as a mandatory security
checkpoint for any application or service that tries to access a website outside
your organization.

## Benefits

Secure Web Proxy provides the following key benefits:

- **Outbound traffic governance of AI agents** . When integrated with
  [Agent Gateway](https://docs.cloud.google.com/secure-web-proxy/docs/overview.md.txt#swp-with-agent-gateway), Secure Web Proxy enforces
  centralized security policies for agent to tool, endpoint, or model access. You
  can enforce granular security perimeters, cryptographically verify agent
  identities, inspect *Model Context Protocol* (*MCP*) tool calls, and apply
  Model Armor content sanitization guardrails to outgoing agent traffic.

- **Identity-aware access control**. Access is based on cryptographic workload
  and agentic identities, rather than static network locations:

  - **Agentic identities** : for autonomous AI agents, you can verify agent
    identities by integrating with Identity and Access Management (IAM) and
    [Identity-Aware Proxy (IAP)](https://docs.cloud.google.com/gemini-enterprise-agent-platform/govern/gateways/delegate-authorization.md.txt#configure-authz-iap)
    through Service Extensions extension bindings.

  - **Workload identities** : for non-agentic workloads, you can verify source
    identities by using [service
    accounts](https://docs.cloud.google.com/secure-web-proxy/docs/use-service-accounts),
    [secure tags](https://docs.cloud.google.com/secure-web-proxy/docs/use-tags.md.txt), or client
    certificates with [frontend mutual TLS
    (mTLS)](https://docs.cloud.google.com/secure-web-proxy/docs/use-frontend-mtls-with-swp).

  This identity-centric model enables fine-grained authorization rules that help
  restrict outbound web traffic to authenticated workloads and agents.
- **Strong default security** . Secure Web Proxy has a default
  `deny-all` setting that blocks all outbound traffic until you
  explicitly allow it. Google Cloud automatically manages all
  software and infrastructure updates, which minimizes the ongoing risk of
  security vulnerabilities.

- **Centralized inspection**. Secure Web Proxy consolidates outbound web
  requests from your cloud workloads and connected offices into a single
  inspection point for consistent policy enforcement.

- **Comprehensive observability and tracing** . All outbound traffic is centrally
  logged in Cloud Logging and integrated with
  [Cloud Trace](https://docs.cloud.google.com/secure-web-proxy/docs/distributed-tracing-overview.md.txt) and
  OpenTelemetry. This integration provides complete auditability, incident
  investigation, and end-to-end latency analysis.

## Supported features

Secure Web Proxy supports the following features:

- **Granular outbound access policies**: you can enforce targeted security
  controls based on your traffic type:

  - **Agentic AI traffic** : when deployed as an [Agent Gateway](https://docs.cloud.google.com/secure-web-proxy/docs/overview.md.txt#swp-with-agent-gateway), Secure Web Proxy evaluates MCP method rules, verifies agent identities, and invokes [extension bindings in
    Service Extensions](https://docs.cloud.google.com/secure-web-proxy/docs/deploy-swp-as-agent-gateway#extension-bindings) to sanitize prompts and responses with services such as [Model Armor](https://docs.cloud.google.com/model-armor/overview.md.txt).
  - **Standard web traffic** : for standard web traffic, Secure Web Proxy evaluates [gateway security
    policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview#policies-overview) or [authorization
    policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview#authorization-policies) to identify source workloads by using secure tags, service accounts, or frontend mTLS certificates. The proxy also filters destination hostnames, URLs, headers, and methods.

  This granular feature of policies lets you create and manage specific,
  reusable rule components across multiple Secure Web Proxy instances.
- **Autoscaling Secure Web Proxy Envoy proxies**: Secure Web Proxy
  supports automatically adjusting the Envoy proxy pool size and the pool's
  capacity in a region, which enables consistent performance during
  high-demand periods at the lowest cost. The autoscaling feature
  automatically manages capacity adjustments in a region. This means that you
  don't have to manually monitor and resize your proxy fleet, ensuring
  better performance with less operational time.

- **Service rate limiting** : Secure Web Proxy enforces traffic limits on
  outbound web traffic to prevent resource-intensive clients from exhausting
  service capacity or generating excessive costs, such as those associated
  with *large language model* (*LLM* ) tokens. You can attach service rate
  limiting policies to gateways that are configured with either gateway
  security policies or authorization policies. You can use [rate limiting
  policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview#rate-limiting-policies)
  to prioritize or throttle traffic based on request counts and specific
  client identities, such as mTLS principals or source IP addresses.

- **End-to-end encryption** : client-proxy tunnels can transit over TLS.
  Secure Web Proxy also supports HTTP and HTTPS `CONNECT` for
  client-initiated, end-to-end TLS connections to the destination server. This
  crucial security measure is automatically managed by the service so
  that traffic is secured without requiring the manual configuration or
  monitoring of encryption standards.

- **Cloud Audit Logs and Google Cloud Observability integration**: by using
  Google Cloud Observability, Cloud Audit Logs records both administrative
  actions (policy changes) and access requests and metrics (proxy transaction
  logs) for Secure Web Proxy. This unified,
  built-in view facilitates security monitoring and compliance reporting.

## How Secure Web Proxy works

Secure Web Proxy acts as a mandatory security checkpoint for all web traffic
from your organization's network to the internet. Internal workloads must comply
with Secure Web Proxy security rules before they can reach the internet.

1. **Centralized gateway** : your workloads, such as *virtual machines* (*VMs*)
   and containers, are configured to send all outbound web requests to the
   central Secure Web Proxy instance.

2. **Policy enforcement**: the proxy inspects the request and applies your
   security policies to determine whether to allow or deny the connection.

3. **Secure outbound traffic**: if the request is allowed, then the traffic is
   securely routed out to the internet by using the Google Cloud
   infrastructure, typically Cloud NAT. The proxy also uses
   Cloud DNS to resolve external web addresses.

## Policies and rules

To secure outbound traffic, choose either an authorization policy or a gateway
security policy as your primary security mechanism on your Secure Web Proxy
instance. You can configure only one primary policy model on a single
gateway. In addition, you can optionally configure service rate limiting
policies on top of either primary policy choice.

- [Authorization policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview.md.txt#authorization-policies):
  these policies let you establish identity-based and destination-based access
  control checks when processing outbound requests through your Secure Web Proxy
  instance. We recommend using this policy type for the following scenarios:

  - When you deploy Secure Web Proxy as an [Agent Gateway](https://docs.cloud.google.com/secure-web-proxy/docs/overview.md.txt#swp-with-agent-gateway) to govern agentic traffic.
  - When you deploy Secure Web Proxy for non-agentic traffic that requires frontend mTLS to verify source identities or custom authorization extensions.
- [Gateway security policies and rules](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview.md.txt#policies-overview):
  these policies and rules define access controls for standard, non-agentic
  outbound web traffic. A gateway security policy serves as the container for
  individual security rules that allow or deny traffic based on source identities
  (service accounts or secure tags), destination hostnames, and ports.

- [Service rate limiting policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview.md.txt#rate-limiting-policies):
  these policies let you enforce client-specific and service-wide request rate
  limits on outbound web traffic to protect external destinations from traffic
  overloads and control costs. You can attach a service rate limiting policy to a
  gateway that uses either an authorization policy or a gateway security policy.

## Agent Gateway integration with Secure Web Proxy

Enterprise AI workloads deployed across Google Cloud---including
*Software as a Service* (*SaaS* ) solutions such as Gemini Enterprise,
*Platform as a Service* (*PaaS*) environments such as
Vertex AI Agent Engine, and containerized or self-hosted runtimes on
Google Kubernetes Engine (GKE) and Cloud Run---require robust,
centralized network boundaries to enforce data privacy, compliance policies, and
threat prevention.

[Agent Gateway](https://docs.cloud.google.com/gemini-enterprise-agent-platform/govern/gateways/agent-gateway-overview.md.txt)
provides centralized policy management, cryptographic identity verification, and
security guardrails for AI agents. For agents that run on either
GKE or Cloud Run, you can [deploy a
Secure Web Proxy instance as an
Agent Gateway](https://docs.cloud.google.com/secure-web-proxy/docs/deploy-swp-as-agent-gateway).
This setup lets you enforce centralized security policies for outbound traffic
to LLMs, MCP tools, external APIs, remote agents, or standard web destinations.

Using a Secure Web Proxy instance with an `agentGateway` resource provides
the following benefits:

- **Centralized policy governance** : apply [authorization
  policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview#authorization-policies)
  that are defined on an `agentGateway` resource to your Secure Web Proxy
  instance. This feature lets you create a unified security posture across
  multiple agent environments.

- **Agent identity and mTLS**: use client certificate validation and
  authorization policies to cryptographically verify and restrict outbound
  communications based on the agent's identity.

- **MCP tool restriction** : enforce granular HTTP rules on agent interactions
  with external MCP tool servers, restricting specific tool methods (such as
  `tools/list` or `tools/call`) and method parameters.

- **Payload verification and sanitization** : integrate directly with
  [Model Armor](https://docs.cloud.google.com/model-armor/overview.md.txt) by using
  extension bindings in Service Extensions to inspect prompts and
  agent responses for sensitive data leaks or prompt injection attacks.

## Deployment modes

You can deploy your Secure Web Proxy instance in any one of the following
modes:

- [Explicit proxy routing mode](https://docs.cloud.google.com/secure-web-proxy/docs/quickstart.md.txt): in this
  mode, you must explicitly configure your workload environments and clients to
  point directly to the proxy server. Secure Web Proxy then isolates your
  clients from the internet. In this way, Secure Web Proxy acts as an
  intermediary, establishing new TCP connections for the client and ensuring that
  every connection meets the requirements of the administered security policy.

- [Private Service Connect service attachment mode](https://docs.cloud.google.com/secure-web-proxy/docs/deploy-service-attachment.md.txt):
  in this mode, you can centralize your web proxy deployments across a complex,
  multi-Virtual Private Cloud (VPC) architecture.

- [Next hop mode](https://docs.cloud.google.com/secure-web-proxy/docs/deploy-next-hop.md.txt): in this mode, you can
  configure your Secure Web Proxy instance to act as a next hop for the
  routing in your network. In other words, you can configure your network routing
  to automatically send outbound traffic to your Secure Web Proxy instance. This
  deployment method reduces your organization's administrative overhead because
  you don't have to manually configure each source workload or client to use the
  proxy.

## Limitations

- **IP versions**: Secure Web Proxy supports only IPv4; IPv6 isn't supported.

- **HTTP versions**: Secure Web Proxy supports HTTP/0.9, 1.0, 1.1, and 2.0
  versions. HTTP/3 isn't supported.

- **Deployment scope**: you can deploy a Secure Web Proxy instance only in a
  host project, not in a service project.

## Additional Google Cloud tools to consider

You can integrate Secure Web Proxy with the following Google Cloud tools
to enhance the overall security posture of your workloads and applications:

- Use [frontend mTLS](https://docs.cloud.google.com/secure-web-proxy/docs/use-frontend-mtls-with-swp.md.txt)
  to enable Secure Web Proxy to configure validated client identities
  in [authorization
  policies](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview#authorization-policies)
  and enforce granular access control for outbound traffic.

- Use [Certificate Manager](https://docs.cloud.google.com/certificate-manager/docs/overview.md.txt) to
  manage the trust anchors (root certificates) and intermediate CAs required
  to validate client certificates in frontend mTLS connections to
  Secure Web Proxy.

- Implement [VPC Service Controls](https://docs.cloud.google.com/secure-web-proxy/docs/vpc-sc-support.md.txt) to
  prevent data exfiltration from Google Cloud services, such as
  Cloud Storage and BigQuery.

- Use
  [Trace](https://docs.cloud.google.com/secure-web-proxy/docs/distributed-tracing-overview.md.txt)
  to get distributed tracing data for outbound requests and analyze
  end-to-end network latency.

## What's next

- [Policies and rules](https://docs.cloud.google.com/secure-web-proxy/docs/policies-and-rules-overview.md.txt)
- [Roles and permissions](https://docs.cloud.google.com/secure-web-proxy/docs/roles-permissions.md.txt)
- [Initial setup steps](https://docs.cloud.google.com/secure-web-proxy/docs/initial-setup-steps.md.txt)
- [Deploy Secure Web Proxy as an
  Agent Gateway](https://docs.cloud.google.com/secure-web-proxy/docs/deploy-swp-as-agent-gateway)