Posts tagged agents

B4.run 0.15: Give each step a contract

Learn what B4.run 0.15 changes for tool steps, structured replies, and sandboxed output, with the upgrade details for your agent app.

Essay · 14 min

First-class CopilotKit: how B4.run fills the chat slots

Learn how B4.run fills CopilotKit v2's chat slots so every agent turn renders as one readable block, in React and in Angular.

Essay · 27 min

20 questions on AI Engineering in 2026 and forward

Twenty questions every AI engineer has to answer, from state and approvals to evals and deployment, in LangGraph with Python and B4.run with TypeScript.

Essay · 25 min

How we built navlog, a flight-planning agent

A tour of navlog, our VFR flight planner for a Cessna 172N: the agent, the tools that do the math, the map, and the open source it runs on.

B4.run 0.14: Show your work

Learn what 0.14 adds for the people using your agent: an activity kit for React and Angular, chats that survive a reload, and src/auth.ts.

B4.run 0.13: A sandbox per thread

Learn what 0.13 adds for threads that need their own environment: per-thread images and permissions, staged workspaces and HTTP reads.

B4.run 0.9 to 0.12: The answer the user sees

Learn what 0.9 through 0.12 changed about the final answer: response schemas, an after hook, returnDirect tools and streamed tool arguments.

Essay · 12 min

What is a software factory?

Software factory is a buzzword again. Here is what the term meant in 1968, what it means in 2026, and what we learned building one with B4.run.

Essay · 23 min

Build a code-fixing agent you can read

Follow a B4.run agent from a failing CLI test through a Docker workspace, independent checks, and approval of the exact change.

B4.run 0.8: The framework around the agent

Learn what 0.5 through 0.8 added around the agent: evals, tool permissions, sandboxes, delegation, typed memory, AG-UI clients and production builds.

Essay · 9 min

B4.run at the edge: The Hono target

B4.run's opt-in Hono target emits a Node-free Cloudflare Workers entry with request-scoped Postgres stores and a tested workerd subset.

Essay · 6 min

Eve and B4.run: Choosing an agent framework

Eve and B4.run both organize agents as files. Here is what that structure gives us, and how to compare the client, runtime and deployment choices.

Essay · 7 min

The App Router for AI Agents

Learn how B4.run uses file-system routes, typed tools, planning, skills and subagents to organize a LangGraph.js agent application.