reins-spend — agent spend under on-chain policy

Public product: Reins. Program cso_agent, demo ticker CSO, Solana Devnet.

Lets an LLM (Cursor / Claude) spend only under on-chain policy. Over-budget and wrong payee fail on-chain (INV-I1 + allowlist), not in the prompt.

New here? Start with QUICKSTART.md — reading a policy needs no key at all.

Install

From this repo (works today):

cd colosseum/agent && npm i
npm run policy
npm run pay-merchant
npm run jailbreak -- over-budget    # must fail
npm run jailbreak -- wrong-payee    # must fail

npm run policy works with REINS_ROOT_OWNER + REINS_AGENT_WALLET alone. Spending needs a root key (fees) and a delegated agent key (npm run setup).

One package, two bins. Once published: npm i -g reins-spend-mcp gives you reins-spend, and MCP clients launch the server with npx -y reins-spend-mcp. A one-off CLI run needs the package flag: npx -y -p reins-spend-mcp reins-spend policy. npm pack is verified in CI; the publish itself is pending npm 2FA.

MCP

Official SDK over stdio. Copy mcp.example.json into .cursor/mcp.json or claude_desktop_config.json. This repo already wires it in .cursor/mcp.json alongside solana-mcp (docs, not spend).

Tools: reins_get_policy · reins_spend · reins_pay_merchant · reins_jailbreak

reins_jailbreak returns passed: true only when the program refused. A missing key or dead RPC reports INCONCLUSIVE rather than a fake win.

Keys

| Key | Holds | Signs | |-----|-------|-------| | Root | SOL + CSO, owns vault | policy changes, tx fees | | Agent | nothing | spend only, capped by policy |

The agent key never falls back to the root key. If it is missing, spend refuses; set REINS_ALLOW_ROOT_AS_AGENT=1 to override for a one-wallet demo. REINS_SECRET_KEY / REINS_AGENT_SECRET_KEY let CI run with no files on disk. See .env.example.

State (.env, agent keypair) lives in the package dir inside this repo, otherwise in REINS_HOME (default ~/.reins).

Build and test

npm run typecheck
npm run test        # error classification, no network
npm run build       # dist/cli.js + dist/mcp.js with shebangs

The SDK (reins-spend-sdk, ../sdk) is bundled into dist, so the published tarball has no monorepo dependency.

Skill

.cursor/skills/reins-spend/SKILL.md — when the user asks the agent to pay an API, run these tools. Never move funds outside spend.