OpenAI on Monday began emailing more than 8,000 developers who applied for its invite-only GPT-5.5 party with a surprise consolation prize: a tenfold increase in Codex rate limits on their personal ChatGPT accounts, effective immediately and lasting through June 5.

"We had over 8,000 people express interest in just 24 hours, and while we wish our office was big enough to welcome everyone, we weren't able to make space for every person who applied," the company wrote in the email, which VentureBeat obtained. "As a small token of appreciation, we've 10x'ed your Codex rate limits until June 5th on your personal ChatGPT account."

The gift is not limited to the lucky few who scored invitations to the party itself. Everyone who raised their hand — whether they were accepted, waitlisted, or turned away — received the rate limit boost, according to the email and confirmed by multiple recipients on social media.

CEO Sam Altman telegraphed the move on X shortly before inboxes started lighting up. "We are gonna do something nice for everyone who applied for the GPT-5.5 party and that we didn't have space for," he wrote. "Hope you enjoy!" The post amassed more than 521,000 views within hours.

What a month of supercharged Codex access actually means for developers

The practical implications are huge. Codex, OpenAI's AI-powered coding agent, operates under daily usage caps that vary by subscription tier. A tenfold increase to those caps gives developers dramatically more room to prototype, debug, and ship code using GPT-5.5 — which OpenAI says matches GPT-5.4's per-token latency while performing at a higher level of intelligence and using significantly fewer tokens to complete tasks.

The 31-day window is generous enough to reshape habits. By flooding thousands of developers with expanded access during a critical adoption period, OpenAI is effectively subsidizing the kind of deep, sustained usage that turns a curious trial into a daily dependency. It is a bet that once developers experience Codex at full throttle, they won't want to go back — and that when the limits reset on June 5, a meaningful number will upgrade their subscriptions to preserve the workflow they've built.

The developer community responded with a mix of glee and regret. "I'm literally not taking my Codex hat off for the month," one developer declared on X. Others kicked themselves for not signing up. "That's the last time I don't sign up just because I'm not in SF," one wrote.

Several users raised a question OpenAI has yet to answer publicly: does the boost stack with the existing Pro $200 tier's 20x multiplier? One user reported that OpenAI support said no — users get whichever limit is higher, not a combined total. "The key question isn't whether the 10x boost is only for party applicants," they wrote. "It's whether it stacks with Pro."

OpenAI did not immediately respond to a request for comment on whether the boost stacks with Pro-tier limits.

Inside the low-key meetup that an AI planned for itself

The rate limit gift is a sidecar to the main event: "GPT-5.5 on 5/5," an invite-only gathering running tonight from 5:55 p.m. to 8:55 p.m. PDT at an undisclosed San Francisco venue. OpenAI billed the evening as "a low-key meetup with Sam and the team behind GPT-5.5," promising food, drinks, community, giveaways, and swag — not a product announcement. Even the address remained secret until invitations were confirmed — a touch of exclusivity that generated its own buzz.

In a detail that doubles as a product demo, Altman revealed that GPT-5.5 itself planned the party. The model proposed the May 5 date, suggested that human developers give the toasts rather than the AI, and recommended setting up a suggestion box for the next-generation model. Altman described this as "weird emergent behavior." Registrations closed shortly after opening due to overwhelming demand, with Codex handling the selection process.

Altman also extended an unlikely invitation. He publicly asked Elon Musk to attend, saying, "He can come if he wants… the world needs more love.” The gesture arrives amid Musk's ongoing lawsuit against OpenAI seeking up to $150 billion in damages — a fact that makes the invitation read less like diplomacy and more like performance art.

Anthropic's competing reception turns a scheduling overlap into a Silicon Valley spectacle

Here is where the story gets interesting. VentureBeat has confirmed that Anthropic is hosting its very own invite-only event in San Francisco on Tuesday evening — a "Media VIP Welcome Reception" at nearly identical times to OpenAI’s party. The reception serves as a warm-up for Anthropic's Code with Claude developer conference, the company's second annual gathering focused on its API, CLI tools, and Model Context Protocol (MCP). The conference proper takes place tomorrow.

The scheduling overlap is difficult to dismiss as coincidence. Both companies are hosting developer-focused events on the same evening, in the same city, targeting many of the same people. Whether this was deliberate counter-programming or genuine coincidence, the optics neatly capture where things stand in the industry's most consequential rivalry.

Anthropic's conference will feature its executive and product teams discussing Claude Code, agent implementation strategies, and the product roadmap — all squarely aimed at the same developer audience that just received a month of free Codex upgrades from OpenAI.

How Anthropic overtook OpenAI in revenue — and what it means for the coding wars

The dueling cocktail hours are a social manifestation of a far more consequential battle playing out in revenue, developer adoption, and investor confidence — one that has tilted sharply in Anthropic's favor.

According to Counterpoint Research data, Anthropic surpassed OpenAI for the first time in global LLM revenue market share in Q1 2026, capturing 31.4% compared to OpenAI's 29%. But the headline near-tie obscures a dramatic structural divergence. Counterpoint estimates Anthropic achieved that share with roughly 134 million monthly active users, compared to approximately 900 million for OpenAI — yielding average monthly revenue per active user of $16.20 for Anthropic versus $2.20 for OpenAI. OpenAI commands massive scale; Anthropic extracts roughly seven times more revenue per user. That gap is the central tension in this rivalry.

The enterprise shift has been building for over a year. Menlo Ventures — whose portfolio includes Anthropic — estimates the company now captures 40% of enterprise LLM spend, up from 24% the prior year and 12% in 2023, while OpenAI's share fell to 27% from 50% over the same period. Anthropic has maintained an almost unparalleled 18 months atop the LLM leaderboards for coding, starting with Claude Sonnet 3.5 in June 2024. That dominance in code — AI's first true killer app — has become the on-ramp to broader enterprise adoption and the engine behind Anthropic's revenue acceleration.

The top-line numbers tell the rest of the story. Anthropic said earlier this month that its annualized revenue has topped $30 billion, up from $9 billion at the end of 2025, with more than 1,000 business customers now spending over $1 million annually — a figure the company says has more than doubled since February.

Sources familiar with Anthropic's financials told TechCrunch the run rate is currently closer to $40 billion, driven largely by demand for Claude Code and Cowork. OpenAI, meanwhile, topped $25 billion in annualized revenue as of February, according to Reuters — but the Wall Street Journal reported that the company has recently missed its own projections for user growth and revenue, with CFO Sarah Friar warning colleagues that if growth doesn't accelerate, the company could face difficulty funding future compute agreements.

The momentum has carried into fundraising at a pace that could redraw the industry's power map. Anthropic raised $30 billion at a valuation of $380 billion in February. Bloomberg reported last week that the company has begun weighing a fresh funding round that would value it at more than $900 billion, potentially leapfrogging OpenAI as the world's most valuable AI startup. OpenAI was valued at $852 billion in late March after closing a record-breaking $122 billion funding round. If Anthropic proceeds at the terms described, the company would not only more than double its valuation but would also surpass OpenAI — a reversal that seemed unthinkable six months ago.

Two parties, two visions, and one city at the center of the AI industry's defining rivalry

For the 8,000-plus developers who applied for the GPT-5.5 party, the immediate value is straightforward: a full month of dramatically expanded Codex usage, free of charge, during a period when both companies are shipping at a breakneck pace. For the industry, the signal is harder to miss. The two most valuable private companies in the world are competing for developer loyalty with a combination of free perks, invite-only parties, celebrity CEO engagement, and multi-billion-dollar enterprise ventures — all within the same 24-hour window, in the same seven-square-mile city.

The broader stakes extend well beyond cocktail napkins and rate limits. Both companies are barreling toward potential IPOs. Both are courting the same Wall Street backers for enterprise joint ventures. Both are racing to define how the next generation of software gets built — and by whom. The developers caught between them are, for the moment, the beneficiaries of a spending war that shows no sign of cooling.

Tonight in San Francisco, the Anthropic reception starts at 5pm. The OpenAI party starts at 5:55pm. VentureBeat will be at both. And somewhere between the two venues, 8,000 developers who couldn't get into either room will be burning through their new rate limits — building the future with whichever model they opened first.

Michael Nunez is an editor at VentureBeat covering artificial intelligence. He is attending both the Anthropic Code with Claude Media VIP Welcome Reception and the OpenAI GPT-5.5 launch party tonight in San Francisco.

This story is developing and will be updated.