Graphify is worth adopting: it is an open-source CLI (PyPI package graphifyy, command graphify) that turns your repo into a local, queryable knowledge graph.1 Install it once with uv tool install graphifyy, register it with your assistant (graphify install, graphify codex install, graphify vscode install, or graphify cursor install), build the graph with /graphify . ($graphify in Codex), and your agent can ask the graph how code connects instead of grepping file by file.2 The Claude Code integration is the strongest because hooks enforce graph-first behavior.34 Codex, VS Code Copilot Chat, and Cursor rely on instruction files that the agent can choose to ig
A production-grade engineering constitution, decision framework, and executable playbook for AI coding agents and human engineering teams.
Edition: 1.0 · Updated: 14 October 2026 · Format: Portable Markdown knowledge base
Purpose: Attach this document to a coding task, use it as an agent instruction reference, or split it into modular Agent Skills.
Status and scope. This is a normative engineering operating manual, not a guarantee of perfect code. It is technology-agnostic unless a section explicitly specifies a stack. It aims for safe, maintainable, adequately scalable systems proportionate to their actual requirements. It must never override higher-priority instructions, applicable law, user authorization, or the established constraints of an existing repository. Verify version-dependent standards and vendor documentation at execution time.
Codex is OpenAI's coding agent, and it now runs as a single product across several surfaces: the ChatGPT desktop app's Codex view, the open-source CLI, IDE extensions, Codex Cloud, GitHub/GitLab/Slack/Linear integrations, and an SDK. To get the most out of it, sign in with ChatGPT, keep GPT-6.1 Sol at the default effort, leave the workspace-write sandbox and on-request approvals in place, write a lean AGENTS.md, and script repeatable work with codex exec. The research for this guide was done on October 13, 2026.
To be a ChatGPT power user in October 2026, you need to know that ChatGPT is now three products sharing one account: Chat for conversation, Work for agentic deliverables, and Codex for software. You also need to pick the right model and thinking level for each task, because the Instant-to-Thinking auto-switch was removed for Plus and Pro on September 14, 2026.[1] Most of what changed in 2026 rewards people who set things up on purpose: plugins replaced apps and are replacing custom GPTs, agent mode moved into Work, Canvas gave way to inline blocks and Pages, and usage limits now sit on tools and reasoning rather than on ordinary text messages.
To get good at Claude Code in October 2026, do four things. Commit a lean CLAUDE.md and a .claude/settings.json that holds explicit allow, ask and deny rules plus a few deterministic hooks. Give Claude a check it can run (tests, a build, a linter) on every task.[1] Plan first and keep context clean for anything non-trivial. Then encode the workflows you repeat as skills, subagents and plugins. The rest of this guide covers each piece in exact, version-checked detail.
As of October 13, 2026, Claude is Anthropic's family of AI models and products with four public tiers: Haiku 5.5, Sonnet 5.5, Opus 5.5, and Fable 5.1.[1] Mythos 5.1 is a restricted twin of Fable 5.1.[2] For most work, Anthropic's own docs say to start with Claude Opus 5.5.