Context Firewall
Raksha AI — May 2026
Overview
The Context Firewall is the final governance layer in the Context Governance architecture. It sits between the assembled agent context — everything the agent has acquired from shell operations, browser sessions, tool responses, and other capability surfaces — and the language model's reasoning state. Nothing enters the model's context window without passing through it.
The Context Firewall addresses a specific failure mode: context that was correctly intercepted and classified at the acquisition layer can still reach the model if assembly-time policy is not enforced. An agent may acquire dozens of context fragments across a session, each individually within policy, but whose combination — when assembled into a single context payload for inference — crosses a data scope boundary. The Firewall evaluates the assembled payload, not just individual fragments.
Its responsibilities span two distinct enforcement points:
Pre-inference context inspection evaluates the full context payload before it is submitted to the model. It applies the agent's active behavior profile data scope constraints, checks for credential patterns and PII that survived earlier redaction, enforces retention policy on context fragments that have exceeded their allowed window, and blocks or redacts content that the agent is not permitted to reason over under its current profile.
Pre-transmission API gateway enforcement operates as the final boundary before context is sent to an external model API — a remote LLM endpoint, an embeddings API, or a multimodal inference service. It inspects outbound payloads for governed content that should not leave the trust boundary, applies last-line-of-defense redaction, and provides defense-in-depth even when earlier interception layers have partial coverage.
The Context Firewall works in conjunction with the Context Accumulator, which tracks the provenance, classification, and retention state of every context fragment in the session. The Firewall's policy decisions are informed by that accumulated state: which surfaces produced the content, which policies governed its acquisition, and whether it is still within its permitted retention window.
This architecture reflects a foundational principle: context governance is not a single checkpoint — it is a layered defense. CaSH and CABR govern at acquisition. The Context Accumulator tracks and classifies. The Context Firewall enforces at inference time. Each layer provides independent protection; together they ensure that what the model reasons over is governed by policy, not determined by whatever the agent happened to encounter.
Full architecture documentation for the Context Firewall — including the payload inspection pipeline, retention policy enforcement, pre-transmission API gateway design, and integration with the Context Accumulator and Session Context Model — will be published alongside the open-source reference implementation.