> ## Documentation Index
> Fetch the complete documentation index at: https://docs.horizon.prefect.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Security and compliance

> An overview of Horizon's identity, access control, data handling, encryption, deployment, and monitoring posture for security reviews.

Horizon centralizes identity, access policy, traffic handling, and hosted server
operations at the platform boundary. For protected MCP endpoints, the gateway
applies identity and access controls before requests reach server code.

<Info>
  Formal assurance reports, security-review materials, and the current
  subprocessor list are available through the
  [Prefect Trust Center](https://trust.prefect.io). For implementation detail
  beyond the public documentation, contact
  [horizon-support@prefect.io](mailto:horizon-support@prefect.io).
</Info>

## Identity and authentication

Human sign-in, including SAML or OIDC single sign-on, is backed by WorkOS. The
Horizon gateway identifies callers to protected MCP servers through interactive
MCP client sign-in tokens or personal and service-account API keys before server
code runs. Dashboard requests act as the signed-in user. REST API requests act
as the user or service account that owns the credential. See
[Authentication](/platform/authentication) for both request paths and
[Single sign-on](/administration/sso) for enterprise identity provider setup.
[API keys](/api-keys) covers credential ownership and lifecycle, while
[external authentication](/platform/external-authentication) covers downstream
OAuth and API-key credentials.

## Access control

After authenticating a caller, Horizon evaluates organization membership,
organization role, server access, and capability policy. Organization roles
govern members and organization settings. Server roles and explicit grants
control access to individual servers, while capability policies can narrow
access to specific MCP tools, resources, and prompts. These checks run at the
gateway before protected MCP traffic reaches server code. See
[Authorization](/platform/authorization) for the request decision flow and
[Roles](/roles) for role definitions.

## Data handling

For each served MCP request, Horizon records the method, server, session, client,
outcome, and acting identity. It also records request and response payloads by
default. You can disable either one per project for future
traffic. Horizon retains traffic records indefinitely, and customers cannot set
a retention period. The experimental sensitive-data redaction feature can block
or mask detected values in tool results, but it is best-effort and is not a
compliance control. See
[Data handling and sensitive-data redaction](/security/data-handling) for the
full storage and redaction behavior.

## Encryption

Horizon individually encrypts stored environment variables and connector
credentials, and its underlying data stores are encrypted at rest. Traffic to
the Horizon dashboard, API, and served MCP endpoints uses HTTPS.
Horizon-generated logs omit stored secret values, and connector credentials are
never returned to callers. The [data protection](/security/data-protection) page
documents these guarantees and where plaintext can appear.

## Deployment and residency

Horizon's generally available control plane and hosted server compute operate in
AWS `us-east-1`, with MCP requests entering through a global serving edge.
Customer-selectable regional residency is not available today. AWS PrivateLink
and customer-managed deployments through BYOC or self-hosting are also not
available today. There is no committed availability date for these options. See
[Hosted servers](/servers/hosted),
[Compute model](/platform/compute-model), and [Deployments](/deployments) for the
current hosted deployment model.

## Audit and monitoring

Horizon provides customer-facing request logs and usage views for served MCP
traffic, including session, client, tool, outcome, and verified user or service
account attribution when Horizon authentication is enabled. These views are
operational records of MCP traffic. Horizon does not currently provide a
customer-facing audit UI for membership, role, access, deployment, configuration,
or secret events. Horizon maintains separate infrastructure audit records for
platform operations, but customers cannot access them in the dashboard. See
[Observability](/observability) for the available views and
[Data handling](/security/data-handling) for what each traffic record contains.