Installation

Install AEGIS and choose your integration method — Python SDK, REST API, or self-hosted source install.

Hosted service offline

The hosted AEGIS API was taken offline in September 2026. The Python SDK, the REST API, and the MCP tools all call it, so they return an error instead of a decision. The engine source (self-hosted install, below) runs locally. Status: undercurrentholdings.com/status.

AEGIS evaluates engineering proposals through six gate checks over caller-supplied metrics. Choose your integration method:

Choose Your Integration

Method	Install	Import	Best For
Python SDK	`pip install aegis-governance`	`from aegis import Aegis`	Python apps calling the hosted API (offline)
REST API	No install needed	curl / httpx / fetch	Any language (hosted API offline)
MCP	`claude mcp add aegis`	AI agent tool calling	Local stdio server; tools call the hosted API (offline)

Python SDK (Recommended)

Install the thin client SDK from PyPI:

pip install aegis-governance

from aegis import Aegis

client = Aegis(api_key="uk_live_xxx")  # or set AEGIS_API_KEY env var
decision = client.evaluate(
    proposal_summary="Add Redis caching layer",
    estimated_impact="medium",
    risk_baseline=0.1,
    risk_proposed=0.3,
)
print(decision.status)  # "proceed" | "pause" | "halt" | "escalate"

API keys were issued at portal.undercurrentholdings.com; a key does not restore evaluation while the hosted service is offline.

See the Python SDK Quickstart for the full guide.

REST API (No Installation)

The hosted API is offline; this is the request shape:

curl -X POST https://api.aegis.undercurrentholdings.com/evaluate \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "proposal_summary": "Add Redis caching layer",
    "risk_proposed": 0.3,
    "risk_baseline": 0.1,
    "complexity_score": 0.6,
    "quality_score": 0.8,
    "novelty_score": 0.4
  }'

See the REST API Quickstart for the full guide.

Self-Hosted / Source Install

The engine is licensed under BSL 1.1. Its repository is private, so this install applies only to people with repository access. It evaluates in-process.

git clone <your-aegis-repo>
cd aegis-governance

# Development install (includes test tooling)
pip install -e ".[dev]"

# Verify installation
pytest tests/ -v --tb=short

Requirements

Python 3.10 or later
No runtime dependencies for core functionality

Optional Dependency Groups

Install additional capabilities as needed:

# With scipy for utility z-score calculations
pip install -e ".[engine]"

# With Prometheus metrics exporter
pip install -e ".[telemetry]"

# With MCP server for AI agent integration
pip install -e ".[mcp]"

# With AWS KMS envelope encryption
pip install -e ".[kms]"

# With HSM (PKCS#11) envelope encryption
pip install -e ".[hsm]"

# Full install (all optional dependencies)
pip install -e ".[all]"

Group	Purpose	Key Packages
`engine`	Utility z-score computation	scipy
`telemetry`	Prometheus metrics exporter	prometheus_client
`config`	YAML configuration loading	pyyaml
`mcp`	MCP server support	pyyaml, mcp
`crypto`	BIP-340 Schnorr signatures	btclib, coincurve
`pqc`	Post-quantum (ML-DSA, ML-KEM)	liboqs-python
`persistence`	Workflow state storage	sqlalchemy, asyncpg
`kms`	AWS KMS envelope encryption	boto3
`hsm`	HSM PKCS#11 envelope encryption	python-pkcs11

CLI

The CLI is included with the source install:

pip install -e ".[dev]"
aegis version

Verify Installation

from aegis_governance import __version__, pcw_decide
print(f"AEGIS {__version__} installed successfully")

aegis version

Installation

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