OpenAI's developer platform for building GPT models into your own apps. Documented founders use it inside voice-note apps, resume and cover letter tools, writing assistants and support agents. This is separate from a ChatGPT subscription. In our data, 11 sourced cases name OpenAI API as a tool they used. Of those, 10 report a monthly figure, ranging from $550 to $215,000 a month (median $25,000). These figures are as reported by each source: 2 independently documented, 0 source-supported and 9 self-reported. They are examples, not typical results.
Pay as you go, priced per 1 million tokens and varying by model. For example, the official page listed gpt-6-luna at $0.10 per 1M input tokens and $0.50 per 1M output tokens (standard), and gpt-6-astra at $10.00 input and $50.00 output.
Free plan: No free plan listed; usage is billed per token.
Checked on the official pricing page on October 20, 2026. Prices change and can vary by region, tax, and billing period.
Talknotes (Nicolas Jeanne)
Nicolas Jeanne learned to code in 2022, shipped 17 apps in a year and sold one for $65,000. Talknotes cost him under $10 to build, mainly OpenAI API calls, and reached about $5,000 a month with 5,000 users.
nichesss (Malcolm Tyson)
Malcolm Tyson got GPT-3 access in November 2020 and built nichesss, which suggests business ideas and writes blog posts, ads and social posts. It launched on AppSumo in January 2021 and sold $100,000 in the first month.
CodeGuide (CJ Zafir)
CJ Zafir set out to build 12 startups in 12 months. CodeGuide launched on December 24 and, he says, reached $42K MRR in three months with a community of more than 4,800 AI developers.
CoverLetterGPT (Vince, Wasp)
Vince, a developer relations lead at Wasp, built CoverLetterGPT, a GPT wrapper that writes cover letters, in one week using the free Open SaaS template. He reports about $550 MRR, $9,912 net revenue since launch and average monthly profit of $416.
Rezi (Jacob Jacquet)
Jacob Jacquet started Rezi in 2015 as a job-seeking graduate and built it from Seoul. He says about 2.6 million job seekers have used it and it is at $215K MRR, with 15 employees.
ToneAdapt (Kyan)
Kyan is a college student who had never built anything before. As a guitarist, he was using ChatGPT to work out how to recreate the guitar tones of songs he liked, but the answers were not accurate. Guitarists on Reddit and Instagram had the same problem, so he built ToneAdapt, a website and mobile app that helps a user sound like their favorite song in under 30 seconds.
Formula Bot (David Bressler)
David Bressler built a no-code AI tool while working full time and raising a family. He first called it Excel Formula Bot, and later shortened the name after receiving a cease and desist from Microsoft. It translates text into spreadsheet formulas and adds AI inside Excel and Google Sheets, working much like ChatGPT inside a spreadsheet.
Rytr (Abhi)
Abhi runs a startup platform and incubator, and Rytr is one of its main products. While working with GPT-3 on another chatbot project, he saw that existing AI writing tools were frustrating and decided to build an easier one. Rytr launched in April 2021 with limited resources and a small team.
OpenAssistantGPT (Marc-Olivier Bouchard)
Marc-Olivier Bouchard runs OpenAssistantGPT, started December 2023. Figures: $1,747 MRR, $90,379 all-time.
VoiceCheap (Kevin Rousseau)
Kevin Rousseau founded VoiceCheap in 2024. It dubs and translates videos into multiple languages and offers tools such as text-to-speech, subtitles and AI thumbnails. It also includes VoiceStudio, an AI-native agency that makes videos for businesses.
Simon Bergeron (Lemonbrand.io)
Simon Bergeron runs Lemonbrand.io, a one-person AI consultancy for teams of 5 to 200 people. His second client, a gym owner, paid a $2,500 lump sum that became a $1,500 a month retainer, and is still a client three years later. He now starts with an inbox audit at about $1,500 and sells retainers from about $2,500 a month.
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