CostPilot

CostPilot is a local command-line interface (CLI) for deterministic cost governance in Terraform pull requests. It integrates directly into code review to surface infrastructure cost regressions before changes are merged, when decisions are still reversible.

Key Features

• Pre-Merge Cost Analysis
  Analyzes Terraform plan changes in pull requests and highlights cost-impacting deltas prior to deployment.

• Deterministic Risk Prediction
  Uses static heuristics and embedded pricing data to estimate monthly cost changes with reproducible results.

• Clear Causal Explanations
  Each estimate explains which resources contribute to the change and why.

• Configurable Safety Mechanisms
  Can enforce policy or Service Level Objective (SLO) based blocking when explicitly configured.

• Advisory by Default
  Non-material changes remain silent to avoid unnecessary review noise.

Operational Principles

• Pull Request Focused
  All analysis is scoped to pull requests, not post-deploy billing data.

• Reproducible Outputs
  Same input plan produces the same output every time.

• Local Execution
  Runs fully offline with no cloud credentials, IAM access, or external API calls.

• Explicit Governance
  Blocking is opt-in and policy-driven; advisory output is the default.

Non-Features

CostPilot intentionally does not attempt to solve:

• Unexpected bills from existing infrastructure
• Historical billing analysis or dashboards
• Runtime optimization, autoscaling, or traffic modeling
• Tagging, chargeback, or attribution workflows
• Any workflow requiring live cloud access

Getting Started

CostPilot is distributed as a single native binary and accepts Terraform plan JSON as input.

Example scan:

With policy enforcement:

Exit codes:

• 0 - no risk
• 1 - advisory
• 2 - blocking

For a deterministic walkthrough of typical cost regression scenarios, see the CostPilot Demo repository: https://github.com/Dee66/costpilotdemo

Live demo UI: https://dee66.github.io/costpilotdemo

CostPilot is designed to make infrastructure cost changes visible during code review, without relying on post-deploy billing analysis or cloud access.