Ren Okabe

How to Make an AI Agent in 2026 (Step by Step)

The five parts every AI agent has, a runnable Python example in about 40 lines, and an honest guide to the guardrails and framework choices most tutorials skip.

Claude Agent SDK Custom Tools: Give Your Agent Its Own Functions (2026)

A runnable 2026 guide to custom tools in the Claude Agent SDK: define functions with tool() / @tool, bundle them into an in-process MCP server, register with allowedTools, and gate risky calls per argument with canUseTool. TypeScript and Python.

AI Agent Memory: Long-Term Memory for a Claude Agent in TypeScript (2026)

A runnable 2026 tutorial: build short-term and long-term memory for a Claude agent in TypeScript with message buffers, rolling summaries, and a durable fact store. No vector database required.

Claude Agent SDK vs LangGraph (2026): When Each Wins

A runnable comparison of the Claude Agent SDK and LangGraph in 2026, with the same agent built in both and an honest decision matrix for when each wins.

How to Build an AI Agent With the Claude Agent SDK in Python (2026)

A runnable Python quickstart: install the Claude Agent SDK, stream a run with query(), then give the agent your own tools with the @tool decorator and ClaudeSDKClient. Builds a weather agent that chains two tools.

Build an AI Agent with the Claude Agent SDK in TypeScript (2026)

A runnable 2026 quickstart: install the Claude Agent SDK, wire a custom tool with tool() and createSdkMcpServer(), and let the agent loop call it for you in about 40 lines of TypeScript.

Claude Agent SDK vs Writing the Agent Loop Yourself (2026): When Each Wins

Should you use the Claude Agent SDK or hand-roll the agent loop with the Anthropic Client SDK? An honest 2026 comparison with runnable TypeScript for both and a decision table.

Run Claude Tool Calls in Parallel (TypeScript, 2026)

Speed up your Claude agent loop by running independent tool calls concurrently in TypeScript. Copy-paste code for parallel tool_use, is_error handling, and disable_parallel_tool_use.

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.

Persist Claude tool-call results across page reloads in Next.js (June 2026)

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.

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.