I run a small software company in Tokyo. I am an engineer, not a salesperson. Cold outbound was the part of my job I kept avoiding. So I built an agent that does it for me. It runs as a Claude Code plugin, and the whole stack is open source. This post is about the architecture decisions that mattered.
The product is LeadAce (leadace.ai, source). It is in Public Beta. It finds companies that match your ICP, reads each company's site, writes one email per company, and sends from your own Gmail. Then it collects the replies. And it turns every rejection into a structured reason: budget, timing, wrong buyer, or missing feature. That data changes the next round's targeting.
Why a plugin, not another dashboard
The honest reason: I already spend all day in Claude Code. I did not want to build one more web app with a chat box in it.
Later I found a better reason. A Claude Code plugin runs on the user's own Anthropic plan, on their machine. I do not proxy the LLM calls. So I do not have to charge for them. The price only covers send volume and infrastructure. That is why the entry plan can be $29/mo. My users are developers who already pay for Claude Pro or Max. For them, "bring your own agent runtime" is a feature, not a limitation.
