Guardian Go Security

Guardian is Vectora’s governance engine, responsible for intercepting all tool calls and ensuring they comply with security policies before execution. In the transition to Golang, Guardian was rewritten to operate natively and in a compiled manner.

Strongly Typed Validation vs Zod

In the previous stack, we used the Zod library (JavaScript) for runtime schema validation. Although flexible, Zod introduced latency and a dependency on a V8 interpreter.

The new Go implementation uses Native Struct Validation:

Feature	Technical Transition	Advantage in Go
Parsing	`zod.parse()` → `json.Unmarshal()`	Lower CPU overhead and zero unnecessary allocations.
Type Guarantee	Runtime Check → Static Check + Tags	Schema errors are detected during deserialization by the internal engine.
Extensibility	Custom Zod functions → Go Interfaces	Complex validations are executed as optimized binary code.

The Interception Engine

Guardian Go acts as a middleware layer between the Main Agent and the Harness Runtime.

    graph LR
    A[Main Agent] -- Tool Call --> G{Guardian Go}
    G -- "1. Pattern Matching" --> B[Compiled Blocklist]
    G -- "2. Schema Validation" --> C[Strongly Typed Structs]
    G -- "3. Path Sanitization" --> D[Trust Folder Resolver]
    G -- Approved --> E[Harness Runtime]
    G -- Rejected --> F[Security Error]

Key Protections

Guardian applies multiple layers of defense to ensure that the sub-agent’s execution remains within the security boundaries set by the user and the organization.

1. Compiled Blocklist

Unlike past versions that read rules from an external JSON, critical Guardian patterns (such as access to /etc/passwd, .env, or .pem keys) are now embedded directly in the Go code. This prevents security behavior from being altered through malicious configuration file injection.

2. Trust Folder Resolver

Go’s file system allows the use of filepath.Abs and os.Readlink atomically to resolve paths before validation. Guardian ensures that the execution scope never leaves the trust folder defined in vectora.config.yaml.

3. Output Sanitization

Guardian doesn’t just monitor what goes in, but also what comes out of the sub-agent. If an MCP tool accidentally tries to return an API token or a sensitive string captured from the console, Guardian Go applies heuristic-based secret masking before the data reaches the LLM.

Part of the Vectora ecosystem · Internal Engineering

Distribution Pipeline Systray Interface