Cost.dev (YC W21) – making agents cost-aware and cheaper to call

We launched Infracost on HN five years ago (https://news.ycombinator.com/item?id=26064588) where our CLI generated cost estimates for infra-as-code, e.g. "this Terraform PR adds $400/mo". The idea was to shift cloud costs (FinOps) left, so engineers get visibility of costs before deployment and make better decisions.Earlier this year we started seeing agent traffic in our logs and it looked like coding agents were calling our CLI. But that CLI wasn't designed with coding agents in mind. We went down a philosophical rabbit hole to see if a CLI is even needed anymore given that Claude, Copilot et al. already follow best practices. Ultimately we decided to create a new CLI from the ground up with coding agents in mind for two reasons:1. We optimized the CLI for agent callers and cut Claude's output token usage by up to 79% and API cost by up to 67% versus a bare-Claude baseline. We wrote a blog documenting our lessons on optimizing user token usage when designing a CLI, e.g. using predicate flags so the agent doesn't compose jq | python | wc pipelines, output format that strips JSON's redundant field names. The blog is here: https://www.infracost.io/resources/blog/we-cut-claude-s-toke...2. With cloud costs, precision matters. Telling a coding agent "make this Terraform cost-optimized" can be expensive and lossy. You burn tokens loading code and policy context into every conversation. Your agent could make up a price and you wouldn't know because it's difficult to verify that across the ~10M price points that AWS, Azure and Google have. The CLI runs static analysis on the code, uses the latest prices from cloud vendors, and passes that context to the coding agent.So that's what we're launching today - Cost.dev: https://cost.dev/.- It runs locally. Your code never leaves your machine, you get a fast feedback loop, and you're not burning API calls p

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72

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Verdict

VALIDATE

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A CLI tool that makes AI coding agents cost-aware by providing accurate cloud pricing data and optimized output formats, reducing token usage by up to 67%.

The pain

Coding agents (Claude, Copilot) lack real-time cloud pricing context and waste tokens on verbose outputs. Engineers using agents to optimize infrastructure can't verify if suggested changes actually reduce costs, and agents hallucinate prices across millions of AWS/Azure/GCP price points. Running agents repeatedly to refine cost optimization burns expensive API tokens.

The gap

Existing CLIs weren't designed for agent consumption, they output verbose JSON with redundant fields and require agents to compose complex pipelines. Cloud pricing data isn't integrated into agent workflows. No tool bridges the gap between agent capabilities and infrastructure cost accuracy.

Build angle

Start with teams already using coding agents for infrastructure work (platform engineers, DevOps). Offer the CLI as a drop-in tool that agents can call to get accurate, agent-optimized cost data. Measure success by token savings and cost accuracy. Expand to other domains where agents need real-time pricing (databases, ML services). Build integrations with popular agent frameworks.

Strengths

  • Proven product-market fit: Infracost already has users and credibility in FinOps space
  • Measurable ROI: 67% cost reduction and 79% token savings are concrete, verifiable claims
  • Timing advantage: Coding agents are proliferating; this solves a real problem they face today
  • Technical moat: Maintaining accurate pricing data across cloud vendors is non-trivial
  • YC pedigree: Team has shipped before and understands how to build developer tools
  • Local execution: Privacy and speed advantages over cloud-based alternatives

Risks

  • Narrow initial TAM: Only relevant to teams actively using coding agents for infrastructure, smaller than general FinOps market
  • Pricing data maintenance: Cloud vendors change prices frequently; keeping data current requires ongoing engineering effort
  • Agent framework fragmentation: Different agents (Claude, Copilot, open-source) may require different integrations; scaling support is costly
  • Competitive response: Cloud vendors could integrate pricing APIs directly into agent frameworks, or LLM providers could add pricing context natively
  • Adoption friction: Requires agents to call external CLI; if agents improve at following best practices natively, the value proposition weakens
  • Monetization unclear: Hard to charge developers for a CLI tool; B2B model (selling to enterprises) may require different positioning

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