Piyush Vyas — WritingField notes on agentic systems, browser agent protocols, deterministic runtimes, and shipping AI products that hold up.https://piyushvyas.com/en-usI Replayed a Browser-Use Agent Session Deterministicallyhttps://piyushvyas.com/blog/deterministic-browser-agents/https://piyushvyas.com/blog/deterministic-browser-agents/Browser agents are unreliable. I recorded one with DBAR and replayed it to prove exactly what happened.Thu, 26 Mar 2026 00:00:00 GMTdbarbrowser-usedeterminismbrowser-agentsreplayIntroducing Skill Contractshttps://piyushvyas.com/blog/introducing-skill-contracts/https://piyushvyas.com/blog/introducing-skill-contracts/Declarative contracts for agent skills. What a skill promises, what actually happened, and a framework to audit the gap.Thu, 26 Mar 2026 00:00:00 GMTskill-contractsagent-skillssecurityIntroducing Agent Contractshttps://piyushvyas.com/blog/introducing-agent-contracts/https://piyushvyas.com/blog/introducing-agent-contracts/An open spec for making agent behavior enforceable: cost control, tool-use security, and audit trails at the runtime boundary.Thu, 26 Mar 2026 00:00:00 GMTagent-contractsagentssecurityWhat Happens When Two AIs Review Each Other's Codehttps://piyushvyas.com/blog/staff-engineer-v02/https://piyushvyas.com/blog/staff-engineer-v02/staff-engineer v0.2.0: DADS, Google-grade hooks, visual QA, and one command to set up quality gates.Wed, 18 Mar 2026 00:00:00 GMTclaudecodexdadsqualityIntroducing DBARhttps://piyushvyas.com/blog/introducing-dbar/https://piyushvyas.com/blog/introducing-dbar/A standalone TypeScript package that makes browser agent sessions deterministic and replayable. Freeze time, record networks, hash everything, replay exactly.Thu, 12 Mar 2026 00:00:00 GMTdbarbrowser-agentsdeterminismtestingUniversal Semantic Element IDhttps://piyushvyas.com/blog/introducing-useid/https://piyushvyas.com/blog/introducing-useid/Stable element identity for browser agents across runs. uSEID fuses ARIA semantics, DOM structure, and visual position into signatures that survive UI churn.Thu, 12 Mar 2026 00:00:00 GMTuseidbrowser-agentselement-identityMeet staff-engineerhttps://piyushvyas.com/blog/principal/https://piyushvyas.com/blog/principal/A Claude Code plugin for the full dev lifecycle. What I built and why.Sat, 14 Feb 2026 00:00:00 GMTclaudepluginautomationOne Round-Triphttps://piyushvyas.com/blog/one-round-trip/https://piyushvyas.com/blog/one-round-trip/How BAP's composite actions cut browser agent latency from 5-10 round trips to one.Mon, 02 Feb 2026 00:00:00 GMTbapperformancelatencyMCP vs CLI vs SKILL.mdhttps://piyushvyas.com/blog/mcp-vs-cli/https://piyushvyas.com/blog/mcp-vs-cli/Real benchmarks, token costs, and a decision framework from shipping all three.Thu, 22 Jan 2026 00:00:00 GMTmcpcliskill-mdThe Lethal Trifectahttps://piyushvyas.com/blog/lethal-trifecta/https://piyushvyas.com/blog/lethal-trifecta/BAP accesses private pages, processes untrusted content, and takes external actions. How I secured all three.Sat, 10 Jan 2026 00:00:00 GMTsecuritybaptrustI Audited 53 Agent Skills. Here's What Broke.https://piyushvyas.com/blog/auditing-53-agent-skills/https://piyushvyas.com/blog/auditing-53-agent-skills/Every SKILL.md from Anthropic, OpenAI, and Vercel through my pipeline. The data.Sun, 14 Dec 2025 00:00:00 GMTskill-toolsauditdataDeterministic Tooling for Agent Skillshttps://piyushvyas.com/blog/introducing-skill-tools/https://piyushvyas.com/blog/introducing-skill-tools/Parse, lint, score, and route SKILL.md files. No LLMs anywhere in the pipeline.Mon, 01 Dec 2025 00:00:00 GMTskill-toolsclibm25Semantic Selectorshttps://piyushvyas.com/blog/semantic-selectors/https://piyushvyas.com/blog/semantic-selectors/Why I built BAP around accessibility roles instead of CSS selectors.Thu, 20 Nov 2025 00:00:00 GMTbapaccessibilityselectorsBrowser Agent Protocolhttps://piyushvyas.com/blog/introducing-browser-agent-protocol/https://piyushvyas.com/blog/introducing-browser-agent-protocol/An open standard for AI agents to control web browsers. Why I built it and how it works.Sun, 09 Nov 2025 00:00:00 GMTbapmcpopen-sourceBooking Open Play Before It's Gonehttps://piyushvyas.com/blog/browser-agents/https://piyushvyas.com/blog/browser-agents/The Lifetime Fitness open play battle that led me to build Browser Agent Protocol.Tue, 28 Oct 2025 00:00:00 GMTbappickleballautomationMCP is USB-C for Agentshttps://piyushvyas.com/blog/mcp-60-seconds/https://piyushvyas.com/blog/mcp-60-seconds/The mental model I use after building 30+ MCP integrations at AWS.Wed, 15 Oct 2025 00:00:00 GMTmcpagentsexplainer