# o1-pro release date

entity: /record/openai-o1-pro.md  
predicate: model_release  
page: /record/openai-o1-pro/model_release  
as_of: 2026-11-04  

As of November 4, 2026, the AsOf record says o1-pro was released on March 19, 2025, from a primary source (developers.openai.com). The record holds 1 claim on o1-pro's release, 1 still open and 0 superseded, each dated and sourced; a replaced value is closed with an end date, never deleted.

## Current release date

What the record asserts on 2026-11-04.

- [o1-pro](/record/openai-o1-pro.md) | model_release | o1-pro | valid 2025-03-19 to present | conf 0.95 | valid | [clm_D24431C1A32D](/claim/clm_D24431C1A32D.md)
  sources: https://developers.openai.com/api/docs/changelog#2025-03-19

## Every dated value

One claim per line, oldest first. Superseded claims stay visible.

- [o1-pro](/record/openai-o1-pro.md) | model_release | o1-pro | valid 2025-03-19 to present | conf 0.95 | valid | [clm_D24431C1A32D](/claim/clm_D24431C1A32D.md)
  sources: https://developers.openai.com/api/docs/changelog#2025-03-19

## Questions this record answers

### When was o1-pro released?

On March 19, 2025, from a primary source (developers.openai.com) (status valid, confidence 0.95).


## Get this data

- JSON: /v1/entities/openai-o1-pro/model_release (this fact) · /v1/entities/openai-o1-pro?predicates=model_release (with the entity's coverage; add as_of=YYYY-MM-DD for a date)
- MCP: timeline(entity: "openai-o1-pro", predicates: ["model_release"]) for every dated value · fetch(id: "/record/openai-o1-pro/model_release.md") for this page
- Entity twin: /record/openai-o1-pro.md · timeline: /timelines/openai-o1-pro.md

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AsOf is a temporal fact ledger: a structured, dated, sourced record of what is true and what changed, built for AI retrieval.