Pay-per-call NFT API v3 from Alchemy via MPP (Tempo or Stripe settlement)
What it does
Alchemy's NFT API v3 is exposed through the Machine Payment Protocol (MPP) at mpp.alchemy.com, enabling agent-purchasable, per-call access to NFT data across Alchemy's supported blockchain networks. The endpoint pattern `/:network/nft/v3/:endpoint` allows callers to specify both the target chain and the specific NFT API method (e.g., getNFTs, getNFTMetadata, getContractMetadata, etc.) as path parameters.
The endpoint is live and returns a 402 Payment Required challenge advertising two settlement methods. The first is **Tempo** (crypto rails on chain ID 4217) priced at 1000 base units of token `0x20C0…b50` — likely pathUSD with 6 decimals, making the per-call cost approximately $0.001. The second is **Stripe** (card rails) with an advertised amount of 0 USD, suggesting a metered or subscription-based billing model through Stripe. Both methods use the "charge" intent, meaning each API call is settled individually.
Documentation is sparse on the MPP gateway itself — no OpenAPI spec, no /docs, /api, or /pricing pages are served. The gateway hints that agents should install skills via `npx skills add alchemyplatform/skills --yes` for programmatic usage. For details on the underlying NFT API v3 capabilities (supported chains, available endpoints, response schemas), refer to Alchemy's main documentation at docs.alchemy.com. Without an exposed schema on the MPP gateway, callers will need to consult those external docs to construct valid requests.
Capabilities
Use cases
- —Querying NFT metadata (name, image, attributes) for a given token ID and contract
- —Looking up all NFTs owned by a specific wallet address across supported chains
- —Retrieving collection-level data such as floor price and total supply
- —Verifying NFT ownership for token-gating or access-control workflows
- —Building NFT portfolio dashboards or analytics tools
Fit
Best for
- —AI agents needing on-demand NFT data without managing API keys
- —Applications requiring multi-chain NFT queries through a single endpoint
- —Developers who want pay-per-call pricing without monthly commitments
Not for
- —High-volume batch indexing where a dedicated Alchemy plan would be cheaper
- —Non-NFT blockchain data (use Alchemy's Core RPC or other APIs instead)
- —Minting or writing NFT transactions (this is a read-only data API)
Quick start
# Probe the endpoint to receive the MPP 402 challenge
curl -i https://mpp.alchemy.com/eth-mainnet/nft/v3/getNFTsForOwner
# After obtaining a payment receipt, include it in the header:
curl -H 'Payment: <receipt>' \
'https://mpp.alchemy.com/eth-mainnet/nft/v3/getNFTsForOwner?owner=0xABC...&withMetadata=true'Endpoint
Quality
The endpoint is confirmed live with a valid 402 MPP challenge advertising two payment methods and pricing. However, no OpenAPI schema, no documentation pages, and no example request/response data are available from the MPP gateway itself. Capabilities are inferred from the endpoint name and Alchemy's known NFT API v3 product.
Warnings
- —No OpenAPI or schema documentation is served by the MPP gateway
- —No /docs, /api, or /pricing pages available — all return 'Cannot GET'
- —The Stripe challenge shows amount '0' in USD which is ambiguous — actual card billing model is unclear
- —The Tempo token address (0x20C0…b50) and chain ID 4217 are not independently verified; price of ~$0.001 per call is inferred assuming 6-decimal pathUSD
- —Specific NFT API v3 sub-endpoints and supported networks must be looked up in Alchemy's main docs
Citations
- —The endpoint returns a 402 MPP challenge with tempo and stripe methods, intent=chargehttps://mpp.alchemy.com/:network/nft/v3/:endpoint
- —Tempo method requests 1000 base units of token 0x20C0…b50 on chain 4217; Stripe method requests amount 0 in USDhttps://mpp.alchemy.com/:network/nft/v3/:endpoint
- —Gateway root describes itself as a Payment Gateway supporting x402 and mpp protocolshttps://mpp.alchemy.com
- —Gateway hints agents should install skills via npx skills add alchemyplatform/skillshttps://mpp.alchemy.com/:network/nft/v3/:endpoint