Show and tell: Casa — encrypted pay-per-call (x402) storage for AI agents

[tony8713]

Hi all — I built Casa, an MCP server for private, durable storage that agents pay for per call. It's live and now in this registry as io.github.tony8713/casa, so I wanted to share it here and ask for feedback.

The problem

Agents increasingly need to persist things — memory, artifacts, intermediate files — but the usual options assume a human: sign up, get an API key, manage a bucket. There's no clean way for an autonomous agent to just store a blob privately and durably and pay for it without an account. Casa is an attempt at "Dropbox for agents."

How it works

• Payments via x402 — $0.01 USDC per write/call, settled over the x402 HTTP 402 flow. No accounts, no API keys. Reads are free.
• Durable storage — Arweave by default (permanent), with Swarm used for large files.
• End-to-end encryption — content is encrypted client-side; the server stores ciphertext.
• MCP — exposed as an MCP server so agents can call it natively.

Quickstart

Remote MCP server config:

{
  "mcpServers": {
    "casa": { "url": "https://casa-agents.fly.dev/mcp" }
  }
}

Or run the local package casa-mcp.

Plain HTTP (you'll get a 402 with payment details to satisfy, then retry):

curl -X POST https://casa-agents.fly.dev/store \
  -H "Content-Type: application/json" \
  -d '{"data":"<your encrypted blob>"}'

Live: https://casa-agents.fly.dev · Repo: https://github.com/tony8713/casa

I'd genuinely like feedback from people building MCP servers — especially on the pay-per-call UX and whether the x402 + free-reads model makes sense for agent storage. Happy to answer anything.

[tony8713]

Quick update for anyone who wanted to kick the tires without setup: there's now a free, no-auth way to try Casa.

curl -X POST https://casa-agents.fly.dev/v1/try -d 'hello'

You get back a permanent arweave.net link in one call. The demo store is public + unencrypted (and rate-limited) — it's just to prove permanent storage works in one round-trip. The real path, POST /v1/store, is E2E-encrypted (client-side, zero-knowledge) and paid per call in USDC via x402. Also exposed as an MCP server (casa-mcp local, or hosted /mcp).

Feedback welcome.