ASPERN: counterparty checks for agents

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

• Connection: Runs in the cloud
• Transport: Streamable HTTP
• Category: Online shops & payments

Install

Pick the AI app you use, then copy the settings.

You need

• Runs in the cloudNothing to install; it connects over the internet

Which app do you use?

https://aspern.org/mcp

claude mcp add --transport http aspern https://aspern.org/mcp

{
  "mcpServers": {
    "aspern": {
      "url": "https://aspern.org/mcp"
    }
  }
}

{
  "servers": {
    "aspern": {
      "type": "http",
      "url": "https://aspern.org/mcp"
    }
  }
}

https://aspern.org/mcp

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Tool names and descriptions exactly as the server reported them on Nov 6, 2026. The maker wrote them, not us; we show them as plain text.

• identify

  Call this FIRST whenever you hold something other than a wallet address. Give it a transaction hash, an http(s) URL, a hostname or an ERC-8004 registration number and it says which party that is, with the evidence for the link, so the other tools here can then be called with the

• check_service_endpoint

  Call this before connecting to a service. Give it the http(s) URL of an MCP or A2A endpoint and it says who declares it, whether our daily probe reached it, what it answered with, and how many of the last readings answered. It keeps three things apart and never merges them: what

• preflight_payment

  Call this immediately before sending a payment, every time — not once per counterparty. It weighs THIS payment (the amount, the chain, the endpoint) against what the address has actually done: the price the seller themselves published for that endpoint, the address that endpoint

• vault_assessment

  THE HASH-COMMITTED ASSESSMENT OF A VAULT, in the shape ERC-8004’s Reputation Registry points at, and the only thing here a third party can publish on chain under their own name. Until 2026-10-21 this document was reachable from the API and the web and from NO tool, so an agent co

• vault_exits

  SEND `exitAmountUsd` WITH THE POSITION YOU ARE WEIGHING and this answers whether that size has ever cleared here: the schema has carried it since 2026-10-08, and an auditor still had to find it by guessing because this sentence did not say so. Without it the answer still describe

• vault_risk_dimensions

  SIX RISKS, NOT ONE WORD, across every vault we score. A risk band is a weighted whole and a reader takes it as a summary of everything, which it is not: ours weighs drawdown, crowding, exit, concentration and consistency, and it contains NO reading of who may move the money. Two

• portfolio_screen

  READ THE VAULTS YOU HOLD TOGETHER. This one is about a SET rather than a single subject; an allocator does not hold one subject. This answers the three questions that only exist across holdings and that no vault page can show you: a CONTROLLER behind more than one of them, a MARK

• capital_coverage

  BEFORE YOU TRUST ANY COVERAGE FIGURE FROM US, ask this. It says how much of the market each vault reading actually covers, counted TWO WAYS: by number of open vaults and by the capital in them. They differ by a lot, and the difference is the finding — more than half our vault COU

• exit_lifecycle_coverage

  HOW MUCH OF THE WAY OUT WE CAN SEE, phase by phase, across every open vault. Getting out has four phases — a request filed, something set aside to claim, money that actually left, and an attempt that failed — and we read THREE. The fourth is on this answer anyway, with its reason

• endpoint_coverage

  BEFORE YOU TREAT ANY ENDPOINT AS RELIABLE, ask how well we know. There is no uptime number here and there will not be one, because the states mean different things and summing them produces a figure about nothing: a 402 is an x402 seller doing exactly what it advertises, a 401 or

• payment_evidence

  BEFORE YOU QUOTE ANY FIGURE FOR AGENT COMMERCE, ask which of three it is. Every payment shown to be one, x402 and ACP, is split into three figures that NEST and are never added up (x402 counts only the `protocol`, `route` and `facilitator` tiers below; the authorised transfers wi

• evidence_for

  Everything we hold about one subject, as edges, each carrying where it came from. Use it when you need to explain a decision rather than just make one, or to see what is MISSING before you act. Every edge has `source`, `observedAt` (when the world was in that state), `asOf` (when

• evaluate_action

  Call this when you are about to DO something and need one answer you can act on: pay an address, connect to an MCP server, call a tool, or put capital into a vault. The answer depends on the AMOUNT, the ACTION, the POLICY you name and how much we actually read — so the same addre

• evaluate_vault_decision

  Call this before an agent moves capital into or out of a vault, with the decision it is about to make: the vault, the amount, the MANDATE it must stay inside and the CLAIMS the decision rests on. It is judged against our stored due-diligence snapshot of that vault, deterministica

• simulate_withdrawal

  TRY ONE WITHDRAWAL FROM A VAULT BEFORE YOU MAKE IT. Runs the vault’s own withdraw(amount, holder, holder) by eth_call at the head block, as the holder you name or, if you name none, as its largest depositor: the contract executes and nothing is signed, sent or spent. Says whether

• test_purchase

  WALK THE WHOLE PURCHASE OF AN x402 ENDPOINT WITHOUT PAYING, in the order a buyer actually asks the questions, stopping at the first one that objects. All five are asked in one pass and in that order, so the walk stops where a buyer would stop. Five steps: is the endpoint there, w

• knock_on_endpoint

  KNOCK ON AN x402 ENDPOINT AND GET WHAT IT SERVED. `test_purchase` beside this walks a buy WITHOUT paying and stops at the quote; its own caveat has always said that only paying and reading the answer establishes what arrives, “which is the half that needs your own wallet”. This i

• endpoint_disagreements

  WHICH ENDPOINTS CONTRADICT THEIR OWN LISTING: they ask to be paid at an address the catalogue entry they published does not name. The contradiction appears only when the live handshake and the published listing are held together: either half on its own looks ordinary, since a rea

• list_x402_endpoints

  WHICH ENDPOINTS A PAYEE SELLS, or which ones match some text. The sharpest check a payment can get is the endpoint being bought, and until this a caller had to know its URL by heart. Nearly every catalogued resource names a payee, and the catalogue holds tens of thousands of them

• list_policies

  The policies evaluate_action can be run under, in full: every rule, its id and the sentence it checks. Published deliberately, including to the agents being evaluated — a rule nobody can read is a rule nobody can correct. Free.

• counterparty_check

  Before paying or hiring an agent: what the chain records about that address. Independent payers (counterparties that paid it and were never paid back), the ones it does pay back, how concentrated its custom is, WHETHER THOSE INDEPENDENT PAYERS ARE INDEPENDENT OF EACH OTHER under

• vault_check

  Before putting capital into a vault: what the record shows about it. The headline is what a holder ACTUALLY EARNED set against the advertised rate, with the risk band, the components that apply, who runs it, and `keys`: who can move the money. Read `keys.actsAlone` before any ret

• find_vaults

  Find a vault by what it has DONE rather than what it is called. Free. The filter worth knowing is `earned`: `short` returns the vaults where a holder earned LESS than the venue advertises — how many there are is in the answer, never here — and `beating` the ones where they earned

• operator_check

  The question that follows vault_check: who runs the money, and how much of it is their own. Free. Read `ownShare` with its limits, which travel inside it: the leader’s holding is readable on Hyperliquid and Drift ONLY, so elsewhere it is ABSENT and not zero, the median describes

• list_vaults

  The vaults we read, so a caller holding a name rather than a slug can find the one it means. Free. Absence from this list means we do not read that vault, never that it does not exist.

• find_agents

  Find agents to hire by what the chain records rather than what they claim: filter every address ever paid on x402, Virtuals ACP, the Olas mech marketplace or Masumi by independent payers, dealings, ACP completion, whether its declared service answers, whether it pays its own paye

• counterparty_history

  How one agent’s record has moved: dealings, independent payers, concentration and delivery, day by day. PAID, one cent a call over x402 — the median price of this rail. Without payment the tool answers with the price and how to pay it, and the free check remains available. The hi

• vaults_earned

  What depositors actually KEPT, against what their vault advertised. READ `population` BEFORE QUOTING ANY SHARE FROM THIS. The comparison covers only the vaults where we hold BOTH an advertised rate and a realised one, which is a narrow and lopsided set, usually dominated by one v

• agent_changes

  What moved in the agent record, across every agent, since a date. The counterparty check answers what is true about one address NOW; this answers what changed, for all of them, which is the question anybody holding a list asks next. One row per FIELD that moved, not per address:

• counterparty_bulk

  Check up to fifty addresses in one call, each with its observations, AND what the set shares underneath: the parties that two or more of them pay. That second part is the one answer no per-address row can contain, because the input is your own shortlist — four agents stopping tog

• agent_dependencies

  If your firm relies on several external agents, what do they rest on AT ONCE? Give it two to twenty-five addresses and it finds the parties more than one of them pays. THE PRODUCT IS THE DISTINCTION, NOT THE JOIN: finding that three agents paid the same address tells you almost n

• agent_business

  Does this agent have a BUSINESS, and can any of it be demonstrated? Six questions an investor, a marketplace or an operator actually asks, each answered separately: are the addresses paying it really independent customers; is revenue growing or shrinking; how much is repeat custo

• agent_economic_profile

  One agent, four readings, in the order a buyer actually asks them: what it EARNS and from whom, whether its contracted work FINISHED and who signed it off, who it RESTS ON as a supplier, and whether it is still TRADING and its endpoints answer. Those questions are answered singly

• exit_screen

  YOU HAVE A SIZE AND YOU WANT TO KNOW WHERE IT HAS ACTUALLY CLEARED. Every other exit reading here is about one vault; this asks the same question across every vault whose withdrawal history we have read, which is the question an allocator with capital actually has. Send `amountUs

• vault_exit_confidence

  Before you put capital in, ask what evidence there is that you could get a PARTICULAR amount back out. Every other reading about a vault is about return or about risk of loss; this is about the practical question a holder has, and it is always about a size: "can I get out" has no

• check_action

  CALL THIS BEFORE YOUR AGENT SIGNS ANYTHING THAT MOVES MONEY. One request instead of five: it reads the counterparty record, decodes the calldata you are about to sign, looks up the seller’s own catalogue listing, runs an unpaid 402 handshake with the endpoint, and applies a publi

• inspect_payment

  Call this with the CALLDATA you are about to sign, before you sign it. Every other check here asks whether an address is worth dealing with; this asks whether the transaction is the one you think it is, and the two catch different losses. No amount of reputation makes the recipie

• record_receipt

  Call this AFTER you have paid an address or called a tool, to put what you did on the record. Until now this platform answered "should I" and never heard what happened, which is the difference between a lookup and a control layer: a receipt lets the next question about this subje

• receipt_status

  What became of a receipt you recorded with `record_receipt`. We do not take a receipt on your word: each one is read against the payments WE read from the chain and judged `verified` (it paid the subject and the amount agrees), `contradicted` (which of the two did not), `not-foun

• monitor_subject

  Ask to be told when the answer about an address CHANGES. The dimensions are the ones the counterparty check already answers, so this is that same reading on a schedule rather than a second opinion; what it adds is the comparison. The first run records a reading and reports nothin

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 8, 2026

• ✓ Pass

  Maker matches the repo

  The registry name was verified against the domain aspern.org (the registry checks domain ownership)

• … Not checked yet

  Still maintained

  We have not read this repo from GitHub yet

• … Not checked yet

  Has a licence

  We have not read this repo from GitHub yet

• ✓ Pass

  Endpoint responds

  Responded in 50 ms (HTTP 200)

• – Not applicable

  Sign-in with OAuth

  No sign-in needed

• ✓ Pass

  No hidden instructions in tool descriptions

  Read 40 tool descriptions and found no hidden instructions to the AI

Compared with others in Online shops & paymentsi

• More stars than 0% of the other 2546 servers in this category
• Published to the registry more recently than 86% of the other 2546 servers in this category
• Basic checks equal to or better than 100% of the other 2546 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

README from the maker

claude mcp add --transport http aspern https://aspern.org/mcp

{

{

curl -s https://aspern.org/mcp \