Wind it once. It runs.
Mainspring is an autonomous outbound system. A set of AI agents researches accounts, writes and sends sequences, protects deliverability, handles replies and books meetings, all inside the rules you set. Built on Amazon Bedrock AgentCore.
A mainspring is the coiled spring inside a mechanical watch. Wind it once and it drives every gear, tick by tick, with no hand on it. That's the job.
The whole mechanism →Six agents. One loop that doesn't stop.
Each agent does one job and hands its work to the next. Together they cover everything between a target list and a booked meeting, the work a managed outbound program usually needs a team for.
Research
Builds and refreshes the account list from your fit criteria and live trigger signals: funding, hiring, leadership changes, migrations.
Contacts
Finds the buying committee at each account, verifies every address before it's used, and records why each person is worth writing to.
Writer
Drafts short, specific messages tied to one problem each recipient owns, using only claims from your approved library.
Sender
Runs separate sending domains and mailboxes, warms them, paces volume and watches bounce and complaint rates.
Replies
Reads every reply, stops the sequence, answers routine questions and objections, and hands real interest to booking.
Booking & report
Books qualified meetings onto your calendar with a brief, logs everything to your CRM, and reports on meetings and pipeline.
Autonomous doesn't mean unsupervised.
You approve the rules once: who to target, what you offer, which claims are allowed, how much to send. Mainspring follows them on every message, and stops itself when the numbers say something is wrong.
What it always does
- Writes only from your approved claims library
- Sends from separate domains, never your primary one
- Paces volume to what each mailbox can sustain
- Honors opt-outs immediately and stops on any reply
- Pauses sending when bounce or complaint rates cross your limit
What it never does
- Blast unverified, bought-by-the-thousand lists
- Use fake “Re:” or “Fwd:” subject lines
- Invent customers, results or partnerships
- Count opens as success
- Keep going after someone says no
Agent infrastructure built for production.
Mainspring's agents run on Amazon Bedrock AgentCore, AWS's managed service for running AI agents in production. It's headed for AWS Marketplace, so you'll be able to buy it through the AWS account you already have.
Isolated agent sessions
Each agent runs in its own session on managed infrastructure. Nothing to host or patch.
Scoped access
Agents reach your CRM, calendar and mailboxes only through the access you grant, and only for the job they do.
Every action traced
Each account researched, message sent and reply handled leaves a record you can audit.
The system, and the team behind it.
Mainspring is the product arm of RevenueHouse, a revenue marketing agency for technical B2B companies. The playbook the agents follow comes from the outbound programs RevenueHouse runs for clients: how to research an account, how to write to a technical buyer, and how to protect a sending domain.
Want the system run for you, along with positioning, content and the rest of the funnel? That's RevenueHouse.
Questions we get
Is it really fully autonomous?
Once you've approved the setup, yes. Mainspring researches, writes, sends, follows up, answers routine replies and books meetings without approving each message. You set the rules and limits, and you can require sign-off at any step while you build trust in it.
Will it send from our company domain?
No. Mainspring sends from separate sending domains and mailboxes that point back to your site. If deliverability ever suffers, your primary domain and everyday email are unaffected.
Who takes the meetings?
Your team does. Mainspring books qualified meetings onto your calendar with a short brief on the account, the contact and what they replied to.
Can we buy it through AWS Marketplace?
The AWS Marketplace listing is in preparation. During early access, we'll set up terms with you directly.
How is this different from RevenueHouse's managed outbound?
Mainspring is the system. RevenueHouse is the team. Mainspring runs outbound autonomously, and RevenueHouse can run it for you alongside go-to-market and full-funnel work.
Wind it once. Let it run.
Early access is open to a small number of technical B2B companies. Tell us who you sell to and we'll tell you whether Mainspring fits.