---
id: "entity-codex"
type: "entity"
entityType: "product"
canonicalName: "Codex"
aliases: ["OpenAI Codex"]
source_timestamps: ["00:05:29", "00:20:50"]
tags: ["openai", "tooling", "code-execution"]
related: ["concept-system-matters", "framework-reference-ui-workflow", "entity-gpt-5-5"]
sources: ["s26-gpt55-claude-gemini"]
sourceVaultSlug: "s26-gpt55-claude-gemini"
originDay: 26
---
# Codex

## Profile
OpenAI's coding and execution environment. Allows models like [[entity-gpt-5-5|GPT-5.5]] to:
- Act on files (read, edit, write).
- Run code and tests.
- Drive browsers.
- Compose multi-step agentic workflows.

## Why It's Central
Codex is the **system around the weights** that the speaker invokes in [[concept-system-matters]] and [[quote-system-around-weights]]. It transforms GPT-5.5 from a chatbot into an **agentic worker**, operationalizing the [[concept-can-it-carry|'can it carry?']] paradigm.

## Where It Appears in Workflows
- The **Build** step of [[framework-reference-ui-workflow]].
- The execution layer for [[action-route-complex-execution]].
- The implementation half of [[action-mockup-to-code]].

## External Verifiability
The original OpenAI Codex (2021) was deprecated and migrated into ChatGPT Code Interpreter / Advanced Data Analysis. The 2026-era 'Codex' described in the source appears to be a re-launched or renamed agentic environment; specifics are unverified.