OpenAI's coding-specialized model for long-horizon agentic software engineering, large refactors, migrations, and structured code review.
Output Speed *
Intelligence Index *
Context Window *
Input price
Output price
Performance
Where GPT-5.2-Codex Earns Its Place: Sustained Agentic Coding
Benchmarks
GPT-5.2-Codex Benchmarks: Coding-Weighted, Not Generalist-Leading
Output Speed
Intelligence Index
MMLU *
GPQA *
HLE *
LiveCodeBench *
Technical Specifications
What the model supports
Limitations & Trade-offs
Best-Fit Workloads
Where this model earns its place
Repository-scale refactors and migrations
The 400,000-token context and long-horizon design target exactly this. GPT-5.2-Codex includes improvements on long-horizon work through context compaction and stronger performance on large code changes like refactors and migrations. An agent can hold broad codebase context and iterate across many turns. Best suited to autonomous or supervised background runs where completion quality matters more than immediate latency.
Structured code review
The model is trained to reason over dependencies and validate behavior against tests, making it well-suited to automated pull-request review that flags real defects rather than surface issues. Its improved steerability and closer instruction adherence over GPT-5.1-Codex help enforce team-specific review standards. Useful in CI pipelines that gate merges, though verbose output should be constrained for concise review comments.
Long-running coding agents
GPT-5.2-Codex is built to sustain extended, multi-hour engineering runs while adapting reasoning depth per step. Configurable reasoning.effort lets an orchestrator use lower effort for small edits and xhigh for hard subtasks. Fits Codex CLI, IDE extension, and cloud-task workflows where the model plans, edits, installs dependencies, and validates autonomously across a session.
Defensive cybersecurity engineering
GPT-5.2-Codex has stronger cybersecurity capabilities than any prior OpenAI model.It is very capable in the cybersecurity domain but does not reach High capability under the Preparedness Framework. This supports vulnerability triage and defensive code review; the dual-use nature means deployment should follow the provider's safety guidance and appropriate access controls.