Aegis MCP (v0.1)

Aegis encodes a project's threat model in security-context.yaml and exposes deterministic security guidance through MCP tools for coding agents.

What Was Executed From the Build Plan

The repository now includes the v0.1 deliverables defined in aegis-build-plan.md:

• Schema design
  • JSON Schema: schemas/security-context.schema.json
  • Example: examples/security-context.example.yaml
  • Template: templates/security-context.template.yaml
• MCP server
  • Tooling surface in src/aegis/server.py
  • Tools: aegis_assess, aegis_validate, aegis_init
  • Resource: aegis://summary
• Deterministic assess semantics
  • Matching/merge/conflict logic in src/aegis/engine.py
• Validation
  • Schema + normative contract checks in src/aegis/validation.py
• Security context generation
  • aegis_init in src/aegis/init_tool.py with Claude-assisted mode and deterministic fallback mode
• Agent integration templates
  • agent-templates/
• Reliability feasibility fixtures
  • scenarios/trigger-scenarios.jsonl
  • scenarios/mock-aegis-assess.json

Install

Install from PyPI (recommended):

python -m pip install aegis-mcp

Optional for Claude-assisted aegis_init:

python -m pip install "aegis-mcp[init-llm]"

For local development from this repository:

python -m pip install -e .

Optional local development install with Claude-assisted mode:

python -m pip install -e ".[init-llm]"

Validate a Security Context

aegis-validate examples/security-context.example.yaml

Start the MCP Server

aegis-server --config examples/security-context.example.yaml

Equivalent command from the build plan:

{
  "mcpServers": {
    "aegis": {
      "command": "python",
      "args": ["-m", "aegis.server", "--config", "./security-context.yaml"]
    }
  }
}

Tool Contract

aegis_assess response always includes:

• requirements
• approved_patterns
• anti_patterns
• matched
• warnings
• conflicts
• no_match

See aegis-build-plan.md and docs/schema-reference.md for details.