Key findings
- Google maps the old Vertex AI names to the new ones on one name-changes page, and the launch post says all Vertex AI services and roadmap now ship through Agent Platform.
- Gemini 4 Argon lists at US$4 input and US$20 output per million tokens on the global endpoint. Through Nov 30, 2026 Google returns 50% of net Argon spend as promotional credits, so the effective rate is US$2 and US$10 after credits. Non-global endpoints cost 10% more.
- Standard PayGo throughput follows 30-day organization spend, from 500,000 tokens per minute at Tier 1 to 10,000,000 at Tier 4 for Gemini Pro and Argon models.
- Requesty's gateway saw 96% of Gemini requests on Vertex complete in April 2026, while practitioners report 429 errors on new organizations and bills that arrive hours after a job stops.
On April 22, 2026 Google launched Gemini Enterprise Agent Platform as the evolution of Vertex AI and said every Vertex AI service would ship only through it. Model prices on the global endpoint match each vendor's list, so the platform's own rules set the bill: throughput tiers that follow spend, a 10% premium on non-global endpoints, per-request grounding fees and promotions that end this year.
What the rename changed
Google's launch post calls Agent Platform the evolution of Vertex AI. It brings model selection, model building and agent building together with new features for agent integration, DevOps, orchestration and security. The name-changes page maps the old Vertex AI product names to the new ones, and practitioners on Hacker News list the rename among earlier Google AI renames as a source of confusion.
The agent pieces are new or rebuilt: Agent Runtime for long-running agents backed by Memory Bank, and Agent Identity, Agent Registry and Agent Gateway for governance. Model Garden and the Agent Development Kit carry over.
How the bill is set
Google publishes each model's price per million tokens, with a global and a non-global row for Gemini 3 and later models. Claude Opus 5.5 lists at US$4 input and US$20 output with US$0.20 cache hits. Provisioned Throughput sells GSUs from US$7.14 per GSU-hour on a 1-week term to about US$2.74 on a 1-year term.
Two promotions end soon. Gemini 4 Argon returns to US$4 and US$20 on Dec 1, 2026, and the Gemini 3.x Flash models move from US$0.75 and US$3.75 to US$1.50 and US$7.50 on Jan 1, 2027. Grounding with Google Search bills per request on top of tokens; one solo developer found his bill about four times his token telemetry until he traced it.
Capacity and reliability in public accounts
Teams move from AI Studio to Vertex for capacity. One chatbot operator logged 16 AI Studio 503 errors in one day and moved 27 files to Vertex behind one client factory. The move can also fail: an agent app operator reported persistent 429 RESOURCE_EXHAUSTED errors after it, leaving customers without service.
Billing can lag the work. A startup cofounder reported a C$71K bill from a Vertex AI job that ran 14 hours overnight after startup credits ran out, with charges appearing hours and days later. A Google Developer Expert's composite postmortem traced a tripled bill to a retry loop only after two hours, because nine services shared one unlabeled project.
Methodology
GILD built this piece from Google's Agent Platform launch post, name-changes page, generative AI pricing page, and its Standard PayGo, Provisioned Throughput and endpoint locations documentation, all checked Oct 28, 2026. Prices are list prices in US dollars per million tokens on the date checked. Practitioner accounts are public posts dated 2025 or later, each linked in Sources; the Requesty figure comes from Requesty's published April 2026 operational metrics.
Products in this piece
Sources
- Official documentation
- 6
- Public source
- 6
- Google Cloud blog: Introducing Gemini Enterprise Agent Platform (Apr 22, 2026)
- Agent Platform documentation: Name changes from Vertex AI
- Google Cloud: Agent Platform generative AI pricing
- Agent Platform documentation: Standard PayGo
- Agent Platform documentation: Provisioned Throughput
- Agent Platform documentation: Deployment and endpoint locations
- Requesty: Operational metrics per provider, April 2026 (May 9, 2026)
- junhee916 on DEV: Google AI Studio 503 errors, migrated to Vertex AI (Jun 6, 2026)
- Google AI Developers Forum: Persistent 429 RESOURCE_EXHAUSTED on Vertex AI after migrating from AI Studio (Mar 17, 2026)
- junhee916 on DEV: Vertex AI grounding cost gap on a solo VM (Jun 7, 2026)
- r/googlecloud: Got a C$71K Google Cloud bill overnight (Oct 18, 2026)
- karthidec on DEV: Postmortem, the Tuesday our AI bill had no owner (Oct 25, 2026)