> ## Documentation Index > Fetch the complete documentation index at: https://docs.simpuru.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Create a listing > Anyone can sell. Signed in (`Authorization: Bearer`), the listing is sold by the account and `sellerAddress` is ignored. Without a session (scripts), the creator signs the listing with the wallet of `sellerAddress`. The API stores the content and returns its SHA-256 as `contentHash`; protected quotes commit to it. Instant sales pay the creator directly; protected sales lock into the escrow with the platform as seller of record, which pays the creator `price − max(1.5 tADA, 10%)` once the escrow releases. ## OpenAPI ````yaml https://api.simpuru.xyz/openapi.json post /listings openapi: 3.1.0 info: title: Simpuru API version: 0.1.0 summary: Buyer protection for AI agents paying with x402 on Cardano (preprod). description: >- Sellers list design prompts; each listing commits to the SHA-256 of its content. Buyers (people or agents) pay over **x402** on Cardano preprod, either **instant** (pay the seller) or **protected** (lock into our `vested_pay` escrow, released only if delivery checks out). Consumers: the web app (`apps/web`), the buyer agent and protection watcher (`apps/agent`), the MCP server (`apps/mcp`, hosted at `/mcp`), and the arbiter service (`apps/arbiter`, internal). Every on-chain claim can be checked on `https://preprod.cardanoscan.io/transaction/`. license: name: MIT identifier: MIT servers: - url: https://api.simpuru.xyz description: Production (Cardano preprod) - url: http://localhost:4021 description: Local `bun run dev` in apps/api security: [] tags: - name: Account description: >- Sign in with a Cardano wallet (CIP-30 `signData`), then use the session as `Authorization: Bearer `. Every account has a Simpuru wallet: a preprod wallet the platform holds for the owner, funded with tADA, that web purchases and the owner's agents spend from. - name: Catalogue description: Free listing data. - name: Paid content description: 'The x402 paywall: instant or escrow-protected.' - name: Purchases description: Purchase timelines, derived from chain by the seller agent. - name: MCP description: Model Context Protocol endpoint for agents (Claude Code, Cursor, ...). - name: Arbiter (internal) description: Dispute settlement service, `apps/arbiter`, port 4023. Not public. - name: System description: Health. paths: /listings: post: tags: - Catalogue summary: Create a listing description: >- Anyone can sell. Signed in (`Authorization: Bearer`), the listing is sold by the account and `sellerAddress` is ignored. Without a session (scripts), the creator signs the listing with the wallet of `sellerAddress`. The API stores the content and returns its SHA-256 as `contentHash`; protected quotes commit to it. Instant sales pay the creator directly; protected sales lock into the escrow with the platform as seller of record, which pays the creator `price − max(1.5 tADA, 10%)` once the escrow releases. operationId: createListing parameters: - name: X-Simpuru-Proof in: header required: false schema: type: string contentEncoding: base64 contentMediaType: application/json contentSchema: $ref: '#/components/schemas/UnlockProof' description: >- Base64 JSON `UnlockProof` signed by `sellerAddress` (CIP-30 `signData`) over `sha256("simpuru:listing:v1\n" + sellerAddress + "\n" + sha256(content) + "\n" + priceLovelace + "\n" + timestamp)`, at most 5 min old. requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/NewListing' responses: '201': description: Created content: application/json: schema: $ref: '#/components/schemas/Listing' '400': description: Invalid input; `error` says which field content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: No session and no valid signature content: application/json: schema: $ref: '#/components/schemas/Error' components: schemas: NewListing: type: object properties: title: type: string minLength: 1 maxLength: 120 description: type: string minLength: 1 maxLength: 2000 priceLovelace: type: string pattern: ^[0-9]+$ description: ≥ 1,000,000 instant; ≥ 5,000,000 when `protected` is offered. sellerAddress: type: string pattern: ^addr_test1 modes: type: array items: $ref: '#/components/schemas/DeliveryMode' minItems: 1 content: type: string description: What is sold (max 1 MiB). Hashed; never returned by the catalogue. previewMedia: type: string description: https URL ending in .mp4, .webm, .webp or .gif. category: $ref: '#/components/schemas/Category' required: - title - description - priceLovelace - sellerAddress - modes - content Listing: type: object properties: id: type: string title: type: string description: type: string priceLovelace: type: string pattern: ^[0-9]+$ description: Amount in lovelace (1 tADA = 1,000,000). sellerAddress: type: string description: Preprod address that sells (and, instant, gets paid). modes: type: array items: $ref: '#/components/schemas/DeliveryMode' contentHash: type: string pattern: ^[0-9a-f]{64}$ description: SHA-256 of the content the buyer receives. previewMedia: type: string format: uri description: Free https recording of what the prompt builds. category: $ref: '#/components/schemas/Category' createdAt: type: string description: Unix ms. sales: type: integer description: Purchases that were not refunded. sellerReputation: type: object description: >- From the seller's closed escrows: 100 × withdrawn / (withdrawn + refunded). Absent until one. properties: score: type: integer minimum: 0 maximum: 100 basis: type: integer required: - score - basis required: - id - title - description - priceLovelace - sellerAddress - modes - contentHash Error: type: object properties: error: type: string required: - error DeliveryMode: type: string enum: - instant - protected Category: type: string enum: - Landing Page - Hero - Portfolio - SaaS - Fintech - 3D - AI - Editorial - Wellness ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.