Field Notes, 157 Articles

Notes from the foundry

Engineering essays on generative AI, retrieval systems, and what it takes to ship intelligent software to production.

41Tutorial // AgentsWe Open-Sourced an AI Agent for Coverage Citations: And Broke It Twice2026-07-3042ComparisonsAI Agent Memory: Mem0 vs Zep vs Letta2026-07-2943Insights // DevelopmentThe AI Coding Tools Stack: Why Teams Run Cursor, Claude Code, and Copilot Together2026-07-2944Tutorial // Agentsagent-for-accounting: An Open-Source AI Agent for Bank-to-Ledger Reconciliation2026-07-2845AI EngineeringAI Coding Agents in Large Codebases: Why Repository Intelligence Beats a Bigger Context Window2026-07-2746ComparisonsClaude Opus 5 vs Grok 4.5 vs Muse Spark 1.1: Which Agentic Model to Use in 20262026-07-2647AI EngineeringClaude Opus 5 Batch API Tutorial: AI Contract Data Extraction at Scale, with Real Costs2026-07-2548AI EngineeringClaude Opus 5 Effort Parameter Guide: How to Reduce Claude API Costs Without Switching Models2026-07-2549AI EngineeringHow to Build a Long-Running AI Agent with the Claude Opus 5 API: An Overnight Build Log2026-07-2550AI EngineeringHow to Handle Claude Opus 5 Refusals in Production: stop_reason, stop_details, and the Fallbacks Parameter2026-07-2551AI EngineeringGrok 4.5 API Review: Pricing, Performance, and When to Use It Instead of Claude2026-07-2552AI EngineeringGrok Voice API Tutorial: How to Build a Realtime AI Voice Agent for Customer Support2026-07-2553AI EngineeringHow to Build a Multilingual AI Voice Agent with Grok Voice: Hindi, Spanish, and 20+ Languages2026-07-2554AI EngineeringHow to Connect an AI Voice Agent to a Real Phone Number: Grok Voice SIP Setup and Cost Breakdown2026-07-2555AI EngineeringMeta Model API Tutorial: How to Get Started with Muse Spark 1.1 (Pricing, Setup, First Agent)2026-07-2556AI EngineeringHow to Migrate to the Claude Opus 5 API: Breaking Changes, 400 Errors, and a Production Checklist2026-07-2557AI EngineeringHow to Build a Computer Use Agent with Muse Spark 1.1: Cross-Application Workflows That Actually Finish2026-07-2558AI EngineeringMulti-Agent Orchestration with Muse Spark 1.1: How Subagent Delegation Actually Works in Production2026-07-2559AI EngineeringContext Engineering for AI Agents: Managing the Context Window in Production2026-07-2460AI EngineeringHow to Evaluate a New LLM in 48 Hours: The Shadow-Mode Playbook2026-07-23