> ## Documentation Index > Fetch the complete documentation index at: https://developer.usewarp.net/llms.txt > Use this file to discover all available pages before exploring further. # Create a checkout session > Creates a hosted checkout session. Call this from your server with a secret key. The network (mainnet or testnet) is determined by the key: `sk_live_` keys create mainnet sessions, `sk_test_` keys create testnet sessions. Sessions expire 30 minutes after creation. ## OpenAPI ````yaml /openapi.json post /v1/checkout/sessions openapi: 3.0.3 info: title: Warp API version: 1.0.0 description: >- Public Warp API: hosted checkout sessions for Pay with Warp, hosted ZK proof verification, and Warp Verify attestation checks. contact: name: Warp Support email: support@usewarp.net license: name: MIT url: https://opensource.org/licenses/MIT servers: - url: https://api.usewarp.net description: Production security: - bearerAuth: [] tags: - name: Checkout sessions description: Create and track hosted checkout sessions. - name: ZK verification description: Verify Groth16 proofs against circuits deployed from the Warp Platform. - name: Attestations description: Public Warp Verify attestation checks. - name: Health description: Service status. paths: /v1/checkout/sessions: post: tags: - Checkout sessions summary: Create a checkout session description: >- Creates a hosted checkout session. Call this from your server with a secret key. The network (mainnet or testnet) is determined by the key: `sk_live_` keys create mainnet sessions, `sk_test_` keys create testnet sessions. Sessions expire 30 minutes after creation. operationId: createCheckoutSession requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CheckoutSessionCreateRequest' example: amount_usd: 49.99 description: 'Order #1234' metadata: order_id: '1234' return_url: https://example.com/orders/1234 cancel_url: https://example.com/cart responses: '201': description: Session created content: application/json: schema: $ref: '#/components/schemas/CheckoutSession' '400': description: Invalid request content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: invalid_request message: 'amount_usd: Number must be greater than 0' '401': description: Missing or invalid secret key content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: unauthorized message: Invalid API key '429': description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: rate_limited message: Too many requests. Retry after the window resets. components: schemas: CheckoutSessionCreateRequest: type: object required: - amount_usd properties: amount_usd: type: number minimum: 0.01 multipleOf: 0.01 description: Amount to charge in USD. Greater than 0, at most 2 decimal places. example: 49.99 description: type: string description: Shown to the customer on the checkout page. metadata: type: object additionalProperties: true description: >- Your own key-value data, returned on the session and in webhooks. Keys starting with `_warp_` are reserved and rejected. return_url: type: string format: uri description: >- Where the "Back to merchant" button on the payment success page sends the customer. cancel_url: type: string format: uri description: >- Where the "Cancel and return" link on the checkout page sends the customer. CheckoutSession: type: object properties: id: type: string example: ps_8f14e45fceea167a5a36dedd4bea2543 object: type: string enum: - checkout.session amount_usd: type: string description: Amount in USD as a decimal string. example: '49.99' currency: type: string enum: - USD description: type: string nullable: true metadata: type: object nullable: true additionalProperties: true status: $ref: '#/components/schemas/CheckoutSessionStatus' network: type: string enum: - mainnet - testnet description: Determined by the secret key used to create the session. return_url: type: string nullable: true cancel_url: type: string nullable: true expires_at: type: string format: date-time description: 30 minutes after creation. created_at: type: string format: date-time checkout_url: type: string format: uri description: Hosted checkout page to redirect the customer to. example: >- https://checkout.usewarp.net/session/ps_8f14e45fceea167a5a36dedd4bea2543 payment: type: object allOf: - $ref: '#/components/schemas/Payment' nullable: true description: Present on retrieve once a payment has been detected. Error: type: object required: - error properties: error: type: object required: - code - message properties: code: type: string description: >- Machine-readable error code: `invalid_request`, `unauthorized`, `not_found`, `proof_not_ready`, `onchain_unavailable`, `rate_limited` or `internal_error`. example: invalid_request message: type: string description: Human-readable description. CheckoutSessionStatus: type: string enum: - pending - processing - completed - failed - expired description: >- `pending`: waiting for payment. `processing`: a transaction was submitted and is being verified. `completed`: payment verified. `failed`: verification failed. `expired`: no payment within 30 minutes. Payment: type: object description: The on-chain payment for a session. properties: chain: type: string description: Network the customer paid on. example: base token: type: string description: >- Token the customer paid with. You receive this token; there is no conversion. example: USDC tx_hash: type: string description: Transaction hash (lowercase). example: 0x5f2c... amount: type: string description: Token amount paid, as a decimal string. example: '49.99' confirmations: type: integer description: Block confirmations observed. completed_at: type: string format: date-time nullable: true securitySchemes: bearerAuth: type: http scheme: bearer description: >- Your project secret key: `sk_test_...` (testnet) or `sk_live_...` (mainnet). Use it only on your server. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.