Show HN: Cost.dev (YC W21) – making agents cost-aware and cheaper to call https://ift.tt/Omtavou

Show HN: Cost.dev (YC W21) – making agents cost-aware and cheaper to call We launched Infracost on HN five years ago ( https://ift.tt/63xg7p0 ) 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://ift.tt/NV0lH67... 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 per character when you want to fetch prices. - The CLI does the deterministic work. Fetching price points, scanning the code, validating fixes. The coding agent does the natural-language part. You don't have to trust the LLM to remember the rules, and can verify it called the right CLI command. - It provides a consistent rule layer across every tool you use. Get cost estimates in your IDE and your coding agent with a single install. We support Claude Code, GitHub Copilot, Cursor, Windsurf, OpenAI Codex, Gemini CLI, as well as IDEs like VS Code and JetBrains Before we keep building more in that direction, I want to sanity-check with HN: is "agents writing IaC in prod" actually a thing yet, or am I betting on a future that's still a year out? I know software developers are using coding agents heavily, but are platform/infra folks doing that for prod too? Also, if you have any feedback on Cost.dev, I'd love to hear it! https://cost.dev/ June 4, 2026 at 05:00PM

Show HN: Fork of Rsync https://ift.tt/KSHcWhG

Show HN: Fork of Rsync Hello. After hearing of the problematic LLM commits in rsync, I made a fork of rsync. I decided to fork it off release 3.4.1, since I heard that's the last release without the LLM code. https://ift.tt/soL9pir June 4, 2026 at 03:50AM

Show HN: Lint Your Markdown with ESLint https://ift.tt/PWeMjKB

Show HN: Lint Your Markdown with ESLint https://ift.tt/fEpcN8n June 3, 2026 at 07:17PM

Show HN: I created a React alternative using web componnents https://ift.tt/fdjxwiO

Show HN: I created a React alternative using web componnents https://ift.tt/Ey0lqbz June 4, 2026 at 01:30AM

Show HN: Live breath detection and biofeedback from a phone microphone https://ift.tt/UuOR5HQ

Show HN: Live breath detection and biofeedback from a phone microphone https://ift.tt/V3yLOlU June 2, 2026 at 09:32PM

Citywide Muni Goal Rush Connects Soccer Fans Starting June 11

Citywide Muni Goal Rush Connects Soccer Fans Starting June 11
By Nashelly Chavez

The Muni Goal Rush is a new citywide crawl that connects soccer fans across San Francisco from June 11 - July 19. A new citywide crawl — the Muni Goal Rush — is coming to San Francisco! This crawl invites you to root for your favorite teams and explore the city during the FIFA World Cup 26™ SF Bay Area. From June 11- July 19, experience world-class soccer, public transit and the best of nine San Francisco neighborhoods. With amazing prizes and the opportunity to explore, you won't want to miss out. How to play First, pick up a Muni Goal Rush game card. Find it at any of the participating...

Published 2026-06-02T00:00:00Z
https://ift.tt/nfb1h5B

Show HN: RePlaya – self-hosted browser session replay with live tailing https://ift.tt/sb7dprX

Show HN: RePlaya – self-hosted browser session replay with live tailing Hi HN, I'm one of the founders of s2.dev. RePlaya ( https://ift.tt/2dx9n7F ) is a self-hosted browser session replay tool using rrweb ( https://ift.tt/ZtnyMEk ). It occurred to me that a durable stream per session would be a much neater architectural foundation for much of what you'd want from such a tool. As a unique feature, it also made live tailing straightforward because the player can read from the same stream the recorder is appending to. The alternative architecture is likely an ingest firehose which is then indexed, with associated complexity and latency. You'd have to string together multiple data systems like a message queue, a metadata database, and blob storage and/or an OLAP database. Here the only dependency is S2, which has an open source version you can self-host called s2-lite ( https://ift.tt/RdGn7IH ). How it works: - one S2 stream per browser session - large rrweb events (like a full snapshot) get framed across multiple binary S2 records and reassembled on read - active sessions are tailed with an S2 read session, and bridged to the browser over SSE - session listing relies on stream names encoding reverse timestamps, as S2 returns a lexicographic order listing - relying on fencing tokens so a stopped session can't be written to again by a late recorder - retention and GC are handled via S2 stream config, so no background job needed Curious to hear from folks on the tool or the stream-per-session model! https://ift.tt/2dx9n7F June 2, 2026 at 11:10PM