Your first purchase.
Your original receipt.

01 / Website

See the complete journey.

Open the sandbox, choose Sum, enter [5,10] and set a maximum price of 0.001 sandbox USD, the guest purchase limit. Submit once, then review the result and actual cost. Available guest capacity and your assigned limits are shown by the website.

Open the sandbox ↗

Website organization invitations, API credentials and MCP credentials are separate forms of access. Follow the instructions for the access you have been issued. An API or MCP invitation does not activate website sign-in or transfer a guest session.

02 / Agent connection

Connect through hosted MCP.

Use a client that supports Streamable HTTP and custom Authorization headers. Configure the endpoint below with the dedicated MCP bearer supplied for your invited sandbox buyer. Store it in the client’s private configuration or secret store, outside prompts and tool arguments.

Endpoint
https://api.getclearinghouse.com/mcp

This endpoint uses a dedicated MCP credential, not an Optimize or Exchange API token. OAuth-only clients cannot use this alpha connection. No local adapter process is needed for a compatible hosted MCP client.

Save an invocation ID, then buy

Your calling host must create and retain a unique invocation ID before sending. The ID below is an example; use one saved ID for one intended purchase.

{
  "invocationId": "my-saved-calculator-purchase-001",
  "request": {
    "ask": "sum",
    "input": { "values": [5, 10] }
  },
  "waitMs": 1000
}

Send these arguments to clearinghouse_buy. Your account supplies purchasing defaults and limits. If the response is pending or the connection closes, call clearinghouse_resume with the same saved ID:

{ "invocationId": "my-saved-calculator-purchase-001" }

clearinghouse_buy

Purchase work under the account’s configured authority.

clearinghouse_resume

Observe or recover the original purchase.

clearinghouse_clarify

Correct the original request when its receipt asks for clarification.

clearinghouse_capabilities

Read supported operation and input guidance.

The hosted gateway keeps the durable purchase journal. Your client still keeps the original invocation ID across reconnects and restarts. Changing the request under that ID is rejected.

03 / Application connection

Use the ordinary buying API.

Invited API clients use an operator-issued scoped buyer credential. Save the exact input and an idempotency key before making the request. Keep authentication in your application’s private configuration; the placeholders below are illustrative.

POST https://api.getclearinghouse.com/optimizer/v1/buy
Authorization: Bearer <private buyer API credential>
Content-Type: application/json
Idempotency-Key: <your saved key for this purchase>

{
  "request": {
    "ask": "sum",
    "input": { "values": [5, 10] }
  }
}

Retry the identical request with the same key after an uncertain response. Once you have a request ID, read GET /optimizer/v1/buys/REQUEST_ID with the same buyer credential. Do not turn a timeout into a purchase with a new key.

CALCULATOR_BUNDLE=/absolute/client-bundle
CALCULATOR_PRIVATE=/absolute/private-buyer

node --input-type=module - "$CALCULATOR_PRIVATE/http-sum.json" <<'JS'
import {writeFile} from 'node:fs/promises';
import {randomUUID} from 'node:crypto';
await writeFile(process.argv[2], JSON.stringify({
  action: 'buy',
  idempotencyKey: 'sum:' + randomUUID(),
  input: {request: {ask: 'sum', input: {values: [5, 10]}}}
}), {flag: 'wx', mode: 0o600});
JS

node "$CALCULATOR_BUNDLE/examples/local-alpha-onboarding/buyer-http.mjs" \
  "$CALCULATOR_PRIVATE/buyer.json" "$CALCULATOR_PRIVATE/http-sum.json"

04 / Outcome

Read the result. Keep the receipt.

For the configured calculator offer, a completed 5 + 10 purchase returns this example outcome:

{
  "result": { "output": { "status": "answered", "value": 15 } },
  "actualCost": "0.001",
  "financialStatus": "final"
}

The response includes request identity and state. Keep the full receipt in your application. A pending result is normal; seller work can continue after your observation window ends.

Delivery, payment and usefulness are separate. Treat seller output as data to evaluate, not instructions to execute or proof of correctness. This calculator demonstrates purchasing and recovery; it does not establish the economic value of buying arithmetic.

05 / Recorded demonstration · October 27, 2026

An agent bought a result, then recovered it.

Gemini 3.5 Flash-Lite, using LOW thinking, authored this task for the hosted clearinghouse_buy tool. The host had already saved its unique invocation ID.

{
  "request": {
    "ask": "sum",
    "input": { "values": [5, 10] }
  }
}

1. PurchaseThe model requested the sum through hosted MCP and received the seller’s result and receipt. The account’s simulated balance changed from $0.005 to $0.004.
2. Reconnect and recoverA separate, fresh model context called clearinghouse_resume with the original saved invocation. It recovered the same receipt and value; the balance stayed $0.004, with no additional sandbox charge.

The first recovery attempt hit a test-wrapper wait-limit bug before reaching MCP; after correcting the wrapper, a separately recorded, resume-only continuation succeeded.

06 / Continue

Try within the invited sandbox.

Accounts, access expiry, supported operations and simulated balances are finite. Use the contact or support route supplied with your invitation for expired access, unavailable capacity or an unresolved request. Include its request or invocation ID; keep credentials and private inputs out of messages.

There are no real deposits, payment methods or bank payouts in this sandbox. The website, API and MCP use the existing purchasing services; this guide creates no account and submits no work.