Flat monthly plan
No hourly billing, no change orders. One number, agreed up front. Numbers happen on the call, not on a pricing page.
A MANIFESTO IN THREE ACTS · ACT I: WORK THAT SHOULDN'T BE HUMAN
Mainspring builds AI agents and automations, plus whole products from scratch, up to your industry's Uber. If it's software, we ship it. This page is the pitch, start to finish.
ACT II: THE MACHINES
We build mainsprings for companies: small, reliable machines that turn what you already have (your inbox, your data, your tools) into motion. Agents that work, automations that run, apps that sell. And when the brief is a whole product, we build the whole machine, blank repo to launch. One is winding up besideunder you right now.
WHAT WE BUILD
A digital employee with one job, done perfectly: triage, data entry, follow-ups, reporting. With an audit log.
Your tools, finally talking to each other. The workflow your team does by hand, running itself.
Products with a brain: assistants, copilots, retrieval on your data. Shipped to production, not to a slide deck.
The whole product from scratch: a marketplace, a booking platform, the Uber of your industry. AI where it earns its keep, boring tech where it doesn't.
No-limits clause: if it runs on software, it's in scope, from a one-inbox agent to a whole platform from zero.
HOW YOU GET IT: THE SUBSCRIPTION
No hourly billing, no change orders. One number, agreed up front. Numbers happen on the call, not on a pricing page.
The people you meet on the first call are the people doing the work. No handoff chain, no juniors on your budget.
Month to month. Stop winding, the spring holds: pause between projects, pick up where you left off.
Code, repos, infrastructure, IP: all yours from day one, documented and handover-ready.
WEEK ONE, EVERY TIME
MON
The call
TUE
The plan
WED
Build
THU
Build
FRI
Demo, live
WHO'S WINDING IT
João: ten years as a software engineer, three of them running Custom Code Studio, a twelve-person agency shipping for startups and other agencies.
Mainspring is the second act: deliberately small, senior by default, built around a subscription instead of proposals. Less time selling work, more time doing it.
ACT III: RECEIPTS, NOT PROMISES
Shipped under Custom Code Studio · plus work with WGMI Labs and other agencies.
"The inbox agent paid for its month in the first week. We stopped counting after that."
"We stopped writing specs. We describe the problem, and a demo shows up on Friday."
FINALE: MEET AN AGENT · NO EMAIL, NO SALES CALL
The scoper below is one of our agents, a small one. Feed it a bottleneck or a product idea; it drafts your week one and names the machine we'd build.
EPILOGUE: QUESTIONS
Anything with rules and repetition: triage, data entry, follow-ups, document processing, reporting. If a person does it with a checklist, an agent can do it with an audit log, and it never has a Monday.
No. AI is a tool we're fluent in, not a box we live in. We build entire products from scratch: marketplaces, SaaS, mobile, internal platforms. Plenty of them have no AI at all. If it's software, it's ours.
Senior engineers only, the people you meet on the first call. They build the machines; the machines do the work.
Even better. We plug in as the senior layer: shipping alongside your team, or clearing the part of the roadmap they can't get to.
One flat monthly plan, scoped to your roadmap. Exact numbers in the intro call. No proposals, no surprises.
FIM
Week one starts with a thirty-minute call. Bring the problem.