# Using Activity isolation as a security boundary

DevFeed: [Using Activity isolation as a security boundary](<https://devfeed.tech/articles/using-activity-isolation-as-a-security-boundary-36089.md>)

Original publisher: [Read original article](<https://temporal.io/blog/using-activity-isolation-as-a-security-boundary>)

Author: Houman Kargaran

Published: 2026-08-04T00:00:00Z

Content type: tutorial

Language: en

Sources: [Temporal Blog](<https://devfeed.tech/sources/temporal-blog.md>)

Topics: [Security](<https://devfeed.tech/topics/security.md>), [pii](<https://devfeed.tech/topics/pii.md>), [Architecture & Design](<https://devfeed.tech/topics/architecture-design.md>), [MCP Server](<https://devfeed.tech/topics/mcp-server.md>), [data](<https://devfeed.tech/topics/data.md>), [Machine learning](<https://devfeed.tech/topics/machine-learning.md>)

Tags: [community](<https://devfeed.tech/tags/community.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [isolation](<https://devfeed.tech/tags/isolation.md>), [mcp](<https://devfeed.tech/tags/mcp.md>), [mcp-server](<https://devfeed.tech/tags/mcp-server.md>), [ml](<https://devfeed.tech/tags/ml.md>), [pii](<https://devfeed.tech/tags/pii.md>), [security](<https://devfeed.tech/tags/security.md>)

## AI overview

This guest post explains why a regulated application keeps PII scanning, classification, redaction, and storage within a single Temporal Activity. The design prevents sensitive data from crossing Activity boundaries and appearing in the Temporal UI, while using an in-house MCP server, an internal ML model, and a swappable storage layer.

## Source excerpt

How keeping PII scan, classification, and storage inside one Temporal Activity stops raw data from ever crossing a boundary.