@priors/mcp

@priors/mcp

An MCP server that gives an AI assistant (Claude Desktop, Claude Code, or any MCP client) a USDG wallet on Robinhood Chain: pay x402-priced APIs, check balances, read any agent's Priors credit record, and borrow from and repay the agent's own Priors line, and keep its spare USDG saved in a Morpho vault until it needs it.

Just reading? Use the hosted server

No install and no key: https://mcp.priors.trade/mcp (Streamable HTTP) answers the read-only questions (an agent's record and score, the pool's figures, recent loans, the facilitator's services) from the same public data as priors.trade. It holds no key and cannot send a transaction.

claude mcp add --transport http priors https://mcp.priors.trade/mcp

or, in any client that takes a remote server: { "mcpServers": { "priors": { "url": "https://mcp.priors.trade/mcp" } } }.

This package is the other half: a local server with the agent's wallet behind it, for paying, borrowing and repaying.

tool	what it does	needs the key
pay_url(url, method?, body?, max_price_usd?, max_borrow_usd?, use_savings?)	fetch an https URL, pay its x402 402 in USDG if the price is ≤ max_price_usd (default $0.10); once the 402 names the price, if the wallet is short it first takes the difference out of savings (unless use_savings: false), and borrows the gap only if max_borrow_usd is given. Refuses private and local addresses, never follows a redirect, answers within 45 s, and never signs a second payment for a purchase (the same method, URL and body) that is still pending, until its validBefore plus 60 s (a new call resends the same one, also after a restart, in a new session or from another session of the same wallet: see PRIORS_STATE_DIR)	yes
wallet_balance(address?)	USDG and gas ETH of the wallet (or any address)	no (with address)
credit_status(agent_id?)	line, drawn, available, backer, record, score, open loans and due dates; on a stock line, the stock tokens behind it, and available capped by what the stock vault lets it draw	no (with agent_id)
stock_assets(symbol?)	the stock tokens the Priors stock vault accepts: live Chainlink price, whether it lends against each now (or why not: a sharp price move, a multiplier change, a paused or blocked token), loan-to-value	no
stock_position(agent_id?)	the stock tokens behind an agent's stock line: amount, what the vault values them at, loan-to-value, what the line can draw now, any lending hold	no (with agent_id)
borrow(amount_usd, days, dry_run?)	borrow USDG from the line into the wallet; both amounts required; dry_run quotes the fee. A borrow sent whose answer is lost is counted and said to be possibly open (check credit_status)	yes
repay(loan_id? | all, use_savings?)	repay one of the agent's own loans, or all of them earliest due first; another agent's loan is refused. If the wallet is short of what is due, it first takes the difference out of savings (unless use_savings: false)	yes
savings(address?)	what the wallet (or any address) has saved in the savings vault, how much can come out right now, and the USDG in the wallet	no (with address)
save(amount_usd)	move spare USDG from the wallet into the savings vault, where it earns the vault's rate (at most PRIORS_MAX_SAVE_USD per call, PRIORS_MAX_SAVE_TOTAL_USD per run); needs ETH for gas	yes
unsave(amount_usd? | all)	take USDG back out of savings into the wallet: a normal withdrawal, and when that is not enough, the rest from the vault's other markets in the same transaction (only where that costs no penalty); refused before any transaction when even that cannot pay it; needs ETH for gas	yes
autopay_on(cap_usd?, use_savings?, late?, budget_usd?)	turn on Autopay: the wallet approves AutoRepay for a budget (4 x the limit per loan, never unlimited) and enrolls, so each loan is repaid from the wallet (then its savings, if chosen) in the 6 hours before it is due, with no call per loan, while the wallet holds enough. It makes an on-time repayment more likely; it is not a promise. Default limit: the line plus a 30-day fee, at most PRIORS_MAX_AUTOPAY_USD; call again to approve more. Works once AutoRepay is deployed; needs ETH for gas	yes
autopay_off(clear_budget?)	turn Autopay off (and with clear_budget, set the approvals to 0)	yes
score_of(agent_id)	any agent's on-chain score (0 to 1000) and repayment record, plus its Priors Score v2 and trust rung when published	no
find_services(query?)	services registered with the Priors facilitator that accept USDG (GET /merchants), each marked as approved by Priors or self-registered and not reviewed	no
pt_quote(side, amount, slippage_bps?)	quote buying PT-USDG with USDG, selling it before maturity or redeeming it after: what comes out at the oracle's spot rate, the minimum a trade would name, the days to maturity and the fixed APY to maturity	no
pt_position(address?)	the wallet's (or any address's) PT-USDG: balance, what it is worth now, what it pays at maturity, and whether the Priors stock vault takes PT-USDG behind a line yet	no (with address)
pt_buy(amount_usdg, slippage_bps?, dry_run?)	buy PT-USDG with the wallet's USDG through Pendle's router (at most PRIORS_MAX_PT_USD per call, PRIORS_MAX_PT_TOTAL_USD per run); dry_run lists the calls; needs ETH for gas	yes
pt_sell(amount_pt | "all", slippage_bps?, dry_run?)	sell the wallet's PT-USDG for USDG at the market, before maturity; needs ETH for gas	yes
pt_redeem(amount_pt | "all", slippage_bps?, dry_run?)	redeem the wallet's PT-USDG for USDG 1:1, from maturity (2027-03-25) on; needs ETH for gas	yes

Tools that move money state the amounts in their answer, are marked destructive for MCP clients, and their descriptions tell the assistant to confirm with you first. Merchant text (response bodies, listings, redirect targets) comes back between random <<merchant-data …>> markers, as data. They act on Robinhood Chain mainnet.

Savings

Spare USDG doesn't have to sit idle. save puts it in a Morpho vault (Steakhouse USDG by default, a Morpho Vault V2 curated by Steakhouse Financial), where it earns the vault's rate. When the agent has to pay (pay_url) or repay (repay) and its wallet is short, the server takes the difference back out first, and only then borrows. That makes an on-time repayment more likely; it does not guarantee one: savings come out only while the vault's markets have liquidity.

It is the agent's own money in someone else's vault: Priors never holds it, and the saver carries the vault's risks: a loss in one of its markets lowers the share value at once; its curator and allocators choose the markets and some settings change with no timelock; liquidity can be lent out; USDG's issuer can freeze addresses. The rate moves with Morpho's markets. How money goes in and comes out: the Savings section of @priors/x402's README.

How the server handles it: the vault must be a contract whose asset is USDG; save checks the vault's deposit gate before approving, and approves the amount only when the current allowance is lower; every vault transaction is sent with a gas margin; what can come out is found by simulating the withdrawal (Morpho Vault V2 answers 0 to maxWithdraw by design). A failed top-up never stops a payment or repayment, and the answer says what happened.

A top-up is bounded by the call's own time. When time runs out it stops before sending anything; if a withdrawal was already sent and has not confirmed, pay_url neither borrows nor signs, says so, and the next money call waits for that withdrawal. save keeps the USDG that signed, unsettled payments still need.

PRIORS_SAVINGS_VAULT=off stops save and the automatic top-ups, not the way out: savings and unsave keep working on the default vault. Pointing PRIORS_SAVINGS_VAULT at another vault means trusting that vault (the only check is a contract whose asset is USDG); money saved in the default one stays there, and money saved in a custom one is reached by setting that vault again.

PT-USDG

PT-USDG is Pendle's principal token for USDG on Robinhood Chain (the market maturing 2027-03-25, 00:00 UTC): bought below 1 USDG, it redeems for exactly 1 USDG at maturity, so a buyer held to maturity locks in a fixed yield; sold before then, it gets the market's rate at that moment, which can be lower. The pt_* tools trade it through Pendle's router with the same calls as the Priors SDK (sdk/pt-usdg.mjs and sdk/pendle-pt.mjs, bundled here byte for byte): an approval of exactly the trade's amount, right before the router call that uses it; USDG in or out directly (no outside aggregator, no limit orders); the PT or USDG always paid to the wallet itself; and a minimum out (the quote less slippage_bps, 1% by default): the router reverts rather than fill worse. Each call is simulated before it is sent and its receipt checked. The quote is the oracle's spot rate, before the trade's own price impact, so a large trade may need a wider margin.

Once the Priors stock vault lists PT-USDG, an agent's owner can post it behind a line (pt_position says when); until then it is a token the wallet holds. PRIORS_PT=off removes the five tools.

Configure

The only secret is the wallet key, and it is read from the environment variable PRIORS_KEY, never from the command line (a key-shaped argument makes the server exit without starting) and never printed or returned by a tool. Use a dedicated agent wallet holding only what the agent may spend.

variable	default
PRIORS_KEY	none	the agent wallet's private key; without it only the read-only tools work
PRIORS_AGENT_ID	looked up from the identity registry	the Priors agent id the wallet acts for (the lookup finds only identities minted to the wallet since the v2 deploy, never one transferred to it; set it for an older or a bought one, or when the wallet holds several)
PRIORS_RPC	https://rpc.mainnet.chain.robinhood.com	JSON-RPC endpoint (a private URL is redacted from every answer)
PRIORS_FACILITATOR	https://facilitator.priors.trade	where find_services lists merchants
PRIORS_MAX_PRICE_USD	1.00	ceiling on what pay_url may be told to pay per call
PRIORS_MAX_BORROW_USD	25	ceiling on borrow and on pay_url's max_borrow_usd
PRIORS_MAX_SPEND_USD	5	most pay_url may sign in total while the server runs (counted when signed)
PRIORS_MAX_BORROW_TOTAL_USD	25	most borrow and pay_url may borrow in total while the server runs (a borrow sent whose answer was lost counts: it may have opened a loan)
PRIORS_ALLOW_LOCAL	off	1 lets pay_url reach http://localhost and private addresses (local testing only)
PRIORS_SCORE_V2	https://priors.trade/api/score-v2	where score_of reads Priors Score v2; off shows the on-chain score only
PRIORS_STOCK_VAULT	the bundled deployments file's stockVault	the stock vault the stock tools and credit_status read
PRIORS_SAVINGS_VAULT	Steakhouse USDG on Morpho (0xBeEff033F34C046626B8D0A041844C5d1A5409dd)	the USDG vault savings go to; off (or false, 0, no) stops save and the automatic top-ups, while savings and unsave keep working on the default vault. Its value is never echoed
PRIORS_MAX_SAVE_USD	50	most one save call may move into the vault
PRIORS_MAX_SAVE_TOTAL_USD	200	most save may move in total while the server runs
PRIORS_AUTOREPAY	the bundled deployments file's autoRepay (none until AutoRepay v2 is deployed)	AutoRepay v2's address, for autopay_on, autopay_off and the Autopay lines of credit_status; AutoRepay v1 (retired before use) is refused
PRIORS_V5, PRIORS_V5_ROOT	the bundled deployments file's seatVaultV5 and seatVaultV5AgentId (none until V5 is deployed)	SeatVaultV5 and its root's agent id: a borrow on a V5 line (the borrow tool, pay_url) refreshes it first. The agent's key may do so 24 hours after V5 recorded it (noteDelegate, sent for it when needed); until then a borrow goes ahead only within the line's room, and the tool says when the key can borrow more
PRIORS_MAX_AUTOPAY_USD	25	the most autopay_on enrolls per loan (stage 0)
PRIORS_AUTOPAY_RESERVE	on	with Autopay on, pay_url keeps back what loans whose window opens in the next 24 h will pull, and says so when a payment would cut into it; off turns that off
PRIORS_PT	on	off (or false, 0, no) removes the PT-USDG tools
PRIORS_MAX_PT_USD	50	most USDG one pt_buy may spend (sales and redemptions only turn the wallet's PT back into USDG)
PRIORS_MAX_PT_TOTAL_USD	200	most USDG pt_buy may spend in total while the server runs (a buy whose transaction was sent counts, even if its answer is lost)
PRIORS_STATE_DIR	~/.local/state/priors-mcp	where the payments signed and not yet settled are kept (one owner-only file per wallet, never the key, with a short-lived .lock beside it while it is written), so a restart, a new session or another session of the same wallet resends them instead of signing again. An absolute path, or one starting with ~/ (a relative one is refused at start). A payment that cannot be written there is not sent. off keeps them in memory only

Contract addresses (pool, lens, registry, USDG) come from deployments/4663.v2.json, bundled in the package, and the accepted stock tokens from deployments/stock-assets.4663.json. The stock vault's address (live since 2026-09-28) comes from the same deployments file, or from PRIORS_STOCK_VAULT.

Claude Desktop

Settings → Developer → Edit Config (claude_desktop_config.json), then restart Claude Desktop:

{
  "mcpServers": {
    "priors": {
      "command": "npx",
      "args": ["-y", "@priors/mcp@0.6.0"],
      "env": {
        "PRIORS_KEY": "0xYOUR_AGENT_WALLET_KEY",
        "PRIORS_AGENT_ID": "1234"
      }
    }
  }
}

Read-only (no wallet): leave out env. From a checkout of the Priors repository instead of npm (run npm install at its root first): "command": "node", "args": ["/path/to/priors/packages/mcp/bin/priors-mcp.mjs"].

Claude Code

A project .mcp.json that reads the key from your shell's environment, so the file itself holds no secret:

{
  "mcpServers": {
    "priors": {
      "command": "npx",
      "args": ["-y", "@priors/mcp@0.6.0"],
      "env": {
        "PRIORS_KEY": "${PRIORS_KEY}",
        "PRIORS_AGENT_ID": "${PRIORS_AGENT_ID:-}"
      }
    }
  }
}

or, for your user only: claude mcp add priors --scope user -e PRIORS_KEY="$PRIORS_KEY" -- npx -y @priors/mcp@0.6.0 (the key is expanded by your shell from the environment; do not paste it on the command line).

Try it

"What's the Priors score of agent 6228?" · "How much USDG does my wallet hold?" · "Find services that sell token prices" · "Pay https://api.example.com/report, up to 5 cents" · "Borrow $5 for 7 days, show me the fee first".

Tests

npm run test:packages in the Priors repository lists and calls every tool through the MCP SDK's in-memory client and over stdio, and checks that the key never appears in any output or error.