Agent Engineering
Cancel an In-Flight Claude Tool Call From the Browser
Wire AbortController from the browser into the Claude stream and your tools, cancel a run even after a reload, and clean up partial side effects safely.
11 min read27
Tag
#streaming
4 posts tagged.
AI agents
Resume Claude streams across browser reload with Last-Event-ID (June 2026)
Make a Claude turn survive a browser reload: server-side ring buffer keyed by message.id, the WHATWG Last-Event-ID header, and a Next.js App Router Route Handler that replays missed SSE frames in 180 ms. Measured June 2026 on claude-sonnet-4-6.
13 min read50
Production
Relay Claude SSE to the browser in Next.js (June 2026)
A copy-paste Next.js App Router pattern that relays Claude's Messages-API SSE events to the browser via a Route Handler and a fetch+ReadableStream client. Includes the runtime, headers, and disconnect handling that work around the legacy pages/api flushing bug documented in Vercel Discussion #48427. Measured first-token latency: 480 ms; cost approximately $0.0041 per turn with claude-sonnet-4-6 at June 2026 pricing.
11 min read64
From scratch
Stream Claude tool calls in a TypeScript agent loop (June 2026)
A complete TypeScript tutorial for the streaming agent loop on Claude: input_json_delta accumulation, multi-turn dispatch, AbortController cancellation, and the eager_input_streaming workaround for the verified 5 second first-content delay on tool use. About $0.03 per call with claude-sonnet-4-6 at June 2026 pricing.
11 min read43