Codex Knowledge Base
Chrome DevTools MCP and Codex CLI: Closing the Browser Debugging Gap for AI Coding Agents
Every terminal-native coding agent shares one blind spot: the browser. An agent can refactor your React component tree in seconds, but when the rendered.
Browser-in-the-loop testing: Playwright + Chrome DevTools MCP + Codex CLI
Coding agents write code they cannot see running. They generate a component, commit it, and hope the browser agrees. Browser-in-the-loop testing closes that gap.
AWS AgentCore's Managed Harness and Coding Skills: What They Mean for Codex CLI Teams
On 22 April 2026, AWS announced three additions to Amazon Bedrock AgentCore: a managed agent harness, a dedicated AgentCore CLI, and pre-built coding skills.
Automated Harness Synthesis: What AgentFlow's Typed Graph DSL Means for Codex CLI Orchestration
Two independent research papers dropped within 48 hours of each other in late April 2026, and together they crystallise a thesis that practitioners have.
Agent Sandbox Comparison Matrix: Codex Seatbelt vs NVIDIA OpenShell vs Docker sbx
Autonomous coding agents need guardrails. Give a model unrestricted shell access and it will eventually rm -rf something you care about, exfiltrate.
GPT-5.5 Drops: What Changes for Codex Users
Six weeks. That is the gap between GPT-5.4 and GPT-5.5. OpenAI released its newest frontier model on 23 April 2026, rolling it out simultaneously to ChatGPT.
MCP Schema Bloat and System Prompt Tax: Performance Impact of Tool Definitions
Every MCP server you connect to Codex CLI injects its full tool manifest — JSON schemas with parameter descriptions, type annotations, enum constraints.
Contract-Driven API Development with Codex CLI: Using Specmatic MCP for Spec-First Full-Stack Builds
Most agentic coding workflows suffer from the same failure mode: the agent generates code that compiles, passes its own tests.
Codex CLI Hooks Graduate to Stable: MCP Observation, Inline Config, and Auto-Review in v0.124
With the release of Codex CLI v0.124.0 on 23 April 2026, hooks have officially graduated from experimental to stable.
Codex CLI Custom Model Providers: The Complete Configuration Guide
Codex CLI ships with three built-in providers, but the real power lies in its extensible provider framework. Point Codex at any Responses API endpoint with a custom config.toml block.