OpenAI releases GPT-5.5 launch-week data: API revenue growth hits a new high, Codex doubles

OpenAI on May 1 posted 3 metrics one week after the launch of GPT-5.5 on its official account: its self-rating as the “strongest-ever release,” an API revenue growth rate that is at least double any prior model launch, and Codex doubling revenue in less than 7 days. OpenAI attributed the results to the continued rise in enterprise demand for agentic coding (proxy-based coding) tools, and said the same product cadence is underway alongside the launch of Anthropic’s Mythos in sync with GPT-5.5-Cyber on April 30.

3 metrics from the announcement: API revenue growth pace, Codex doubling in 7 days, strongest-ever release

The 3 key figures OpenAI shared this time came from official tweets, with no detailed financial statements: first, GPT-5.5 is a “release with the strongest-ever revenue growth” (OpenAI’s self-assessment); second, the API revenue growth rate is more than 2x that of any prior model launch; third, Codex doubled revenue in less than 7 days. GPT-5.5 was released on April 23 and its API went live on April 24, meaning the “one week” window covers 7 days from April 24 to May 1.

OpenAI’s broader financial backdrop: annualized revenue of about $25 billion, monthly revenue of about $2 billion, and Codex’s global weekly active users of about 4 million. Alongside GPT-5.5, OpenAI rolled out three lines: GPT-5.5, GPT-5.5 Pro, and GPT-5.5-Cyber focused on network security, allowing enterprise customers to obtain both a general model and an enterprise security-specialized model at the same time.

What’s behind Codex doubling: agentic coding enters the enterprise budget cycle

Codex is OpenAI’s agentic coding platform that can autonomously execute multi-step programming tasks in a developer environment. OpenAI attributed the 7-day doubling to “continued growth in enterprise demand for agentic coding tools,” and did not disclose specific contract amounts or customer lists. The same day, OpenAI also launched a Codex workflow import feature that lets developers one-click import existing settings, plugins, agents, and project configurations into Codex—reducing the switching costs from other IDEs or AI coding tools.

Compared with contemporaneous competitors, Anthropic’s Claude Code added mobile push notification prompts in April, and on May 6 will hold a “Code with Claude” developers conference (San Francisco, London, and Tokyo). OpenAI’s Codex and Anthropic’s Claude Code are currently the two main pillars in the agentic coding market.

Next to watch: whether the annualized growth can turn into stable revenue across earnings quarters

The next question is whether OpenAI’s full earnings-quarter data can verify the sustainability of the “2x API growth”—right now the figures cover only a 7-day window after the launch. Enterprise customer contracting cycles are typically measured in quarters, so official revenue contribution may not be fully reflected until Q3. Another item to watch is whether OpenAI will publish the conversion rate and retention rate of GPT-5.5 for the ChatGPT subscription tier (personal and enterprise plans); that part was not mentioned in the tweets.

This article about OpenAI publishing GPT-5.5 launch-week data: API revenue growth hits an innovation high, and Codex doubles, first appeared on Chain News ABMedia.