krabs.dev tracks income, expenses, and cashflow over one API with three equally first-class transports — MCP, HTTP, and CLI. Self-hosted, open source, no login. Built for solopreneurs whose agents do the work.
$ krabs invoice.create --counterparty "Acme Inc" --amount 120000 → { "id": "inv_01J6Q…", "version": 1, "created": true } $ krabs expense.create --amount 4200 --category hosting --dry-run → plan ready · would_create exp_… $ krabs finance.report --from 2026-01-01 → income 480000 · expenses 152300 · net 327700
Agents speak MCP. Humans speak CLI. Apps speak HTTP. krabs answers in all three with the exact same object graph behind it.
{
"mcpServers": {
"krabs": {
"command": "npx",
"args": ["-y", "@krabs/mcp"],
"env": { "KRABS_API_KEY": "$KRABS_TOKEN" }
}
}
}Delete, merge, bulk-update — your agent can do all of it. Every mutation lands in an append-only log with the prompt that caused it.
Account and key operations return an undo token — one call rewinds them. Agents experiment; mistakes do not become incidents.
Products, subscriptions, invoices, expenses — plus finance reporting. The primitives a one-person business actually tracks, and nothing it doesn't.
Retries are safe. Plans are previewable. Agents can show you what they're about to do before they do it.
Self-hosted, open source, MIT. Single account, no sign-up, no billing. SQLite on disk — back it up by copying a file.
GET /v1/schema returns the entire operation catalog. Your agent reads its own manual and stops asking you what's possible.
No demo call. No sign-up. Clone the repo, run setup, you have an API, MCP server, and CLI on localhost. Free and open source.