> ## Documentation Index > Fetch the complete documentation index at: https://agents.laso.finance/llms.txt > Use this file to discover all available pages before exploring further. # Search merchant spend data > Search Laso's merchant database for confirmed spend data for a given card type. Returns whether the card was accepted, not accepted, or unknown at each merchant. Use `card_type` to search by the USA prepaid card (`Non-Reloadable U.S.`, the default) or the international prepaid card (`Non-Reloadable International`). USA searches exclude merchants with non-US country-code TLDs; international searches do not. **Important:** This database only contains merchants where Laso users have previously attempted a transaction. A merchant not being listed, or being listed as `unknown`, does NOT mean the card won't work there — it just means it hasn't been tried yet. If a merchant is listed as `accepted`, you can confidently use the card there. If listed as `not_accepted`, the card will fail at that merchant. Banking and money-transfer merchants are always returned as `not_accepted` with a `restriction_note`, whatever the transaction history shows. Spending there counts as a transfer of value and is not supported on any card. Requires a Bearer token from `/auth` or `/get-card`. ## OpenAPI ````yaml /api-reference/openapi.json get /search-merchants openapi: 3.1.0 info: title: Laso Finance x402 API version: 1.0.0 x-docs-revision: 2c5778b5ce19 x-docs-manifest: https://laso.finance/.well-known/docs-version.json contact: email: agents+support@laso.finance x-guidance: >- Laso Finance is a payment-gated (x402) API that lets an AI agent spend USDC on real-world financial products: prepaid cards (U.S. and international), gift cards, push-to-card transfers to USD/EUR/GBP debit cards, and Venmo/PayPal payouts. Payment: every paid route is an x402 v2 endpoint. Call it with no payment header to receive a 402 challenge listing the accepted networks, then replay with a signed USDC payment. Both Base (eip155:8453) and Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp) are accepted on every paid route; the caller picks either chain. Identity: `GET /auth` is free and identity-only. Prove wallet ownership with a `SIGN-IN-WITH-X` (CAIP-122) header to receive a Firebase id_token, then send that token as a Bearer credential to the authenticated read routes (`get-card-data`, `get-account-balance`, `get-kyc-status`, etc.). Paid routes also return fresh auth credentials in their response, so a payment is never required just to obtain a token. Recommended flow: (1) `GET /auth` to establish identity, (2) call a paid route (e.g. `GET /get-card`) to purchase a product, paying USDC on Base or Solana, (3) poll the authenticated read routes with the returned Bearer token to fetch the resulting card/transfer details. Full machine-readable instructions live at https://laso.finance/SKILL.md. description: >- Payment-gated API for Laso Finance. All paywalled routes use the x402 protocol — the caller includes a USDC payment header on Base (eip155:8453) or Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp) and the server verifies payment before processing. Free routes require no payment header. The same 402 also carries an MPP (Machine Payments Protocol) challenge in WWW-Authenticate; an MPP client pays with USDC on Base by replaying with `Authorization: Payment ...`, and routes, prices, and responses are identical. ## Getting started To set up a wallet for making x402 payments, choose a provider: - **Locus** (default): https://paywithlocus.com/SKILL.md - **Sponge**: https://wallet.paysponge.com/skill.md — automatic x402 service discovery - **Ampersend**: https://www.ampersend.ai/getting-started.md — self-custody on Base or Solana with dual-approval spending limits. Laso Finance is a default skill, so no manual endpoint registration is needed. ## How x402 works 1. Call a paywalled endpoint without a payment header → receive a `402 Payment Required` response containing payment details (price, recipient address, network). 2. Construct an x402 payment header using the details from the 402 response. 3. Replay the request with the payment header → the server verifies payment and processes the request. ## Authentication flow `GET /auth` is free: callers prove wallet ownership by sending a `SIGN-IN-WITH-X` header (CAIP-122 wallet signature). Paywalled routes (`/get-card`, `/order-gift-card`, `/get-push-to-card`, `/order-intl-card`) also return fresh auth credentials in their responses, so a payment is never required just to obtain a token. Most routes return auth credentials (`id_token`, `refresh_token`, `expires_in`). Use the `id_token` as a Bearer token to call authenticated Laso Finance endpoints like `/get-card-data`. When the `id_token` expires, use `POST /auth` with `grant_type: refresh_token` to get a new one. ## Important notes The `/get-card` USA prepaid card endpoint is U.S. only — issued in USD, usable at U.S.-based merchants only, and physical goods must ship to a U.S. address. For non-U.S. merchants or non-USD currencies, use `GET /order-intl-card` instead (international prepaid card, admin-fulfilled within 24 hours). All cards are intended for the caller's own use. ## Rate limits Every response carries the request budget so you can pace yourself without probing for a limit: | Header | Meaning | | --- | --- | | `RateLimit-Limit` | Requests permitted per window | | `RateLimit-Remaining` | Requests still available | | `RateLimit-Reset` | Seconds until the window rolls over | | `RateLimit-Policy` | The policy these numbers describe, as `limit;w=seconds` | The same values are repeated as `X-RateLimit-*` for clients that only parse that spelling. Most routes advertise the service-wide ceiling. `POST /signup` enforces its own per-IP budget on top of it and overwrites these headers with its own numbers. `POST /refresh-card-data` is limited per card rather than per caller, so its headers keep the service-wide values and the per-card budget is reported only on rejection. Every rejection is a `429` carrying `Retry-After` in seconds and a matching `retry_after_seconds` field in the body, computed from the limit that actually rejected the request. Wait that long and retry once. Do not retry in a tight loop. For step-by-step instructions, read https://laso.finance/SKILL.md servers: - url: https://laso.finance description: Production security: [] paths: /search-merchants: get: summary: Search merchant spend data description: >- Search Laso's merchant database for confirmed spend data for a given card type. Returns whether the card was accepted, not accepted, or unknown at each merchant. Use `card_type` to search by the USA prepaid card (`Non-Reloadable U.S.`, the default) or the international prepaid card (`Non-Reloadable International`). USA searches exclude merchants with non-US country-code TLDs; international searches do not. **Important:** This database only contains merchants where Laso users have previously attempted a transaction. A merchant not being listed, or being listed as `unknown`, does NOT mean the card won't work there — it just means it hasn't been tried yet. If a merchant is listed as `accepted`, you can confidently use the card there. If listed as `not_accepted`, the card will fail at that merchant. Banking and money-transfer merchants are always returned as `not_accepted` with a `restriction_note`, whatever the transaction history shows. Spending there counts as a transfer of value and is not supported on any card. Requires a Bearer token from `/auth` or `/get-card`. operationId: searchMerchants parameters: - name: q in: query required: true description: >- Search query — the merchant name to search for (e.g. "amazon", "netflix") schema: type: string - name: card_type in: query required: false description: >- Which card type to search acceptance for. Defaults to `Non-Reloadable U.S.` if omitted (preserves existing client behavior). Pass `Non-Reloadable International` to search for international prepaid card acceptance. schema: type: string enum: - Non-Reloadable U.S. - Non-Reloadable International default: Non-Reloadable U.S. responses: '200': description: Merchant search results content: application/json: schema: type: object properties: merchants: type: array items: $ref: '#/components/schemas/MerchantResult' query: type: string description: The search query that was used count: type: integer description: Number of merchants returned card_type: type: string description: The card type results are filtered for example: Non-Reloadable U.S. note: type: string description: >- Important caveat about the data — this database only includes merchants where users have previously attempted transactions '400': description: Missing search query content: application/json: schema: $ref: '#/components/schemas/Error' example: error: q query parameter is required '401': description: Missing or invalid Bearer token content: application/json: schema: $ref: '#/components/schemas/Error' example: error: Missing or invalid Authorization header security: - BearerAuth: [] components: schemas: MerchantResult: type: object description: >- A merchant from the spend data database with its acceptance status for the Non-Reloadable U.S. card. properties: name: type: string description: Merchant name example: Amazon url: type: string description: Merchant website URL example: amazon.com status: type: string enum: - accepted - not_accepted - unknown description: >- Whether the Non-Reloadable U.S. card is accepted at this merchant. `accepted` = confirmed working, `not_accepted` = confirmed failing or restricted, `unknown` = card type not yet tried at this merchant. restriction_note: type: - string - 'null' description: >- Present when the merchant is restricted rather than merely untested. Banking and money-transfer merchants are always reported as `not_accepted`, because spending there counts as a transfer of value. Approvals do occur at these merchants, so acceptance cannot be read off the transaction history. `null` for every other merchant. description: type: - string - 'null' description: Brief description of the merchant notes: type: - string - 'null' description: Additional notes about using the card at this merchant Error: type: object properties: error: type: string securitySchemes: BearerAuth: type: apiKey in: header name: Authorization description: >- Firebase ID token from `/auth` or any paid route, sent as a Bearer token: `Authorization: Bearer ` (the `Bearer ` prefix is required). ````