diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..210f1f8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+node_modules/
+dist/
+*.tsbuildinfo
+.env*
diff --git a/README.md b/README.md
index 5f1a2e0..bcf377b 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,24 @@
 # x402-directory
-A curated, agent-maintained directory of x402 payment-enabled applications and endpoints. Browse, search, and discover services that accept x402 micropayments. Agents can contribute by adding new listings, verifying endpoint liveness, and categorizing services.
+
+A curated, agent-maintained directory of x402 payment-enabled applications and
+endpoints. Browse, search, and discover services that accept x402 micropayments.
+Agents can contribute by adding new listings, verifying endpoint liveness, and
+categorizing services.
+
+## Listing Data Model
+
+This repository starts with a simple JSON-backed data model for v1 listings.
+
+- `schema/listing.schema.json` defines the JSON Schema contract.
+- `src/schema.ts` exports TypeScript types and category/status constants.
+- `data/listings.json` contains seed listings using the schema.
+- `src/validate.ts` validates the seed data without external runtime dependencies.
+
+## Scripts
+
+```bash
+npm install
+npm run typecheck
+npm run build
+npm run validate
+```
diff --git a/data/listings.json b/data/listings.json
new file mode 100644
index 0000000..2df8bbc
--- /dev/null
+++ b/data/listings.json
@@ -0,0 +1,36 @@
+[
+  {
+    "id": "x402_weather_quote",
+    "name": "Weather Quote API",
+    "url": "https://weather-quote.example/x402",
+    "description": "Returns a paid current-weather summary for a requested city through an x402-protected HTTP endpoint.",
+    "category": "data-feeds",
+    "pricing": {
+      "amount": "0.001",
+      "currency": "USDC",
+      "unit": "request",
+      "network": "base",
+      "details": "Flat per-request price for JSON weather summaries."
+    },
+    "status": "unverified",
+    "createdAt": "2026-05-11T00:00:00.000Z",
+    "updatedAt": "2026-05-11T00:00:00.000Z"
+  },
+  {
+    "id": "x402_agent_icon",
+    "name": "Agent Icon Renderer",
+    "url": "https://agent-icon.example/render",
+    "description": "Generates a small paid PNG icon from a text prompt and returns the image URL after x402 payment.",
+    "category": "ai-ml-apis",
+    "pricing": {
+      "amount": "0.02",
+      "currency": "USDC",
+      "unit": "render",
+      "network": "base",
+      "details": "Per successful image render."
+    },
+    "status": "unverified",
+    "createdAt": "2026-05-11T00:00:00.000Z",
+    "updatedAt": "2026-05-11T00:00:00.000Z"
+  }
+]
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..aa89111
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,47 @@
+{
+  "name": "x402-directory",
+  "version": "0.1.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "x402-directory",
+      "version": "0.1.0",
+      "devDependencies": {
+        "@types/node": "22.15.17",
+        "typescript": "5.6.3"
+      }
+    },
+    "node_modules/@types/node": {
+      "version": "22.15.17",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.15.17.tgz",
+      "integrity": "sha512-wIX2aSZL5FE+MR0JlvF87BNVrtFWf6AE6rxSE9X7OwnVvoyCQjpzSRJ+M87se/4QCkCiebQAqrJ0y6fwIyi7nw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~6.21.0"
+      }
+    },
+    "node_modules/typescript": {
+      "version": "5.6.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.3.tgz",
+      "integrity": "sha512-hjcS1mhfuyi4WW8IWtjP7brDrG2cuDZukyrYrSauoXGNgx0S7zceP07adYkJycEr56BOUTNPzbInooiN3fn1qw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
+    "node_modules/undici-types": {
+      "version": "6.21.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.21.0.tgz",
+      "integrity": "sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==",
+      "dev": true,
+      "license": "MIT"
+    }
+  }
+}
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..4eafa35
--- /dev/null
+++ b/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "x402-directory",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "build": "tsc",
+    "typecheck": "tsc --noEmit",
+    "validate": "npm run build && node dist/src/validate.js"
+  },
+  "devDependencies": {
+    "@types/node": "22.15.17",
+    "typescript": "5.6.3"
+  }
+}
diff --git a/schema/listing.schema.json b/schema/listing.schema.json
new file mode 100644
index 0000000..775386d
--- /dev/null
+++ b/schema/listing.schema.json
@@ -0,0 +1,97 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://github.com/shipyard-projects/x402-directory/schema/listing.schema.json",
+  "title": "x402 Directory Listing",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "id",
+    "name",
+    "url",
+    "description",
+    "category",
+    "pricing",
+    "status",
+    "createdAt",
+    "updatedAt"
+  ],
+  "properties": {
+    "id": {
+      "type": "string",
+      "pattern": "^x402_[a-z0-9_]+$"
+    },
+    "name": {
+      "type": "string",
+      "minLength": 2,
+      "maxLength": 80
+    },
+    "url": {
+      "type": "string",
+      "format": "uri"
+    },
+    "description": {
+      "type": "string",
+      "minLength": 20,
+      "maxLength": 280
+    },
+    "category": {
+      "type": "string",
+      "enum": [
+        "ai-ml-apis",
+        "data-feeds",
+        "compute",
+        "storage",
+        "content",
+        "developer-tools",
+        "identity",
+        "other"
+      ]
+    },
+    "pricing": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": ["amount", "currency", "unit", "network"],
+      "properties": {
+        "amount": {
+          "type": "string",
+          "pattern": "^[0-9]+(\\.[0-9]+)?$"
+        },
+        "currency": {
+          "type": "string",
+          "minLength": 2,
+          "maxLength": 16
+        },
+        "unit": {
+          "type": "string",
+          "minLength": 3,
+          "maxLength": 64
+        },
+        "network": {
+          "type": "string",
+          "minLength": 2,
+          "maxLength": 32
+        },
+        "details": {
+          "type": "string",
+          "maxLength": 180
+        }
+      }
+    },
+    "status": {
+      "type": "string",
+      "enum": ["verified", "unverified"]
+    },
+    "createdAt": {
+      "type": "string",
+      "format": "date-time"
+    },
+    "updatedAt": {
+      "type": "string",
+      "format": "date-time"
+    },
+    "lastCheckedAt": {
+      "type": "string",
+      "format": "date-time"
+    }
+  }
+}
diff --git a/src/schema.ts b/src/schema.ts
new file mode 100644
index 0000000..cc3b38a
--- /dev/null
+++ b/src/schema.ts
@@ -0,0 +1,44 @@
+export const listingCategories = [
+  "ai-ml-apis",
+  "data-feeds",
+  "compute",
+  "storage",
+  "content",
+  "developer-tools",
+  "identity",
+  "other"
+] as const;
+
+export const listingStatuses = ["verified", "unverified"] as const;
+
+export type ListingCategory = (typeof listingCategories)[number];
+export type ListingStatus = (typeof listingStatuses)[number];
+
+export type PricingInfo = {
+  amount: string;
+  currency: string;
+  unit: string;
+  network: string;
+  details?: string;
+};
+
+export type X402Listing = {
+  id: `x402_${string}`;
+  name: string;
+  url: string;
+  description: string;
+  category: ListingCategory;
+  pricing: PricingInfo;
+  status: ListingStatus;
+  createdAt: string;
+  updatedAt: string;
+  lastCheckedAt?: string;
+};
+
+export function isListingCategory(value: string): value is ListingCategory {
+  return listingCategories.includes(value as ListingCategory);
+}
+
+export function isListingStatus(value: string): value is ListingStatus {
+  return listingStatuses.includes(value as ListingStatus);
+}
diff --git a/src/validate.ts b/src/validate.ts
new file mode 100644
index 0000000..f7de769
--- /dev/null
+++ b/src/validate.ts
@@ -0,0 +1,128 @@
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+import {
+  isListingCategory,
+  isListingStatus,
+  type X402Listing
+} from "./schema.js";
+
+type ValidationError = {
+  id: string;
+  field: string;
+  message: string;
+};
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function isIsoDate(value: unknown) {
+  return typeof value === "string" && !Number.isNaN(Date.parse(value));
+}
+
+function isHttpUrl(value: unknown) {
+  if (typeof value !== "string") {
+    return false;
+  }
+
+  try {
+    const url = new URL(value);
+    return url.protocol === "https:" || url.protocol === "http:";
+  } catch {
+    return false;
+  }
+}
+
+function validateListing(value: unknown): ValidationError[] {
+  const errors: ValidationError[] = [];
+
+  if (!isRecord(value)) {
+    return [{ id: "unknown", field: "listing", message: "Listing must be an object." }];
+  }
+
+  const listing = value as Partial<X402Listing>;
+  const id = typeof listing.id === "string" ? listing.id : "unknown";
+
+  if (typeof listing.id !== "string" || !/^x402_[a-z0-9_]+$/.test(listing.id)) {
+    errors.push({ id, field: "id", message: "ID must match x402_[a-z0-9_]+." });
+  }
+
+  if (typeof listing.name !== "string" || listing.name.trim().length < 2) {
+    errors.push({ id, field: "name", message: "Name must be at least 2 characters." });
+  }
+
+  if (!isHttpUrl(listing.url)) {
+    errors.push({ id, field: "url", message: "URL must be a valid HTTP(S) URL." });
+  }
+
+  if (
+    typeof listing.description !== "string" ||
+    listing.description.trim().length < 20
+  ) {
+    errors.push({
+      id,
+      field: "description",
+      message: "Description must be at least 20 characters."
+    });
+  }
+
+  if (typeof listing.category !== "string" || !isListingCategory(listing.category)) {
+    errors.push({ id, field: "category", message: "Category is not supported." });
+  }
+
+  if (typeof listing.status !== "string" || !isListingStatus(listing.status)) {
+    errors.push({ id, field: "status", message: "Status must be verified or unverified." });
+  }
+
+  if (!isRecord(listing.pricing)) {
+    errors.push({ id, field: "pricing", message: "Pricing must be an object." });
+  } else {
+    const amount = listing.pricing.amount;
+    if (typeof amount !== "string" || !/^[0-9]+(\.[0-9]+)?$/.test(amount)) {
+      errors.push({ id, field: "pricing.amount", message: "Amount must be numeric text." });
+    }
+
+    for (const field of ["currency", "unit", "network"] as const) {
+      if (typeof listing.pricing[field] !== "string" || !listing.pricing[field]) {
+        errors.push({
+          id,
+          field: `pricing.${field}`,
+          message: `${field} is required.`
+        });
+      }
+    }
+  }
+
+  for (const field of ["createdAt", "updatedAt"] as const) {
+    if (!isIsoDate(listing[field])) {
+      errors.push({ id, field, message: `${field} must be an ISO date.` });
+    }
+  }
+
+  if (listing.lastCheckedAt !== undefined && !isIsoDate(listing.lastCheckedAt)) {
+    errors.push({ id, field: "lastCheckedAt", message: "lastCheckedAt must be an ISO date." });
+  }
+
+  return errors;
+}
+
+const listingPath = join(process.cwd(), "data", "listings.json");
+const listingData = JSON.parse(readFileSync(listingPath, "utf8")) as unknown[];
+const errors = listingData.flatMap(validateListing);
+const ids = new Set<string>();
+
+for (const listing of listingData) {
+  if (isRecord(listing) && typeof listing.id === "string") {
+    if (ids.has(listing.id)) {
+      errors.push({ id: listing.id, field: "id", message: "ID must be unique." });
+    }
+    ids.add(listing.id);
+  }
+}
+
+if (errors.length > 0) {
+  console.error(JSON.stringify(errors, null, 2));
+  process.exit(1);
+}
+
+console.log(`Validated ${listingData.length} x402 listings.`);
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..b6bf693
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "resolveJsonModule": true,
+    "skipLibCheck": true,
+    "outDir": "dist",
+    "rootDir": ".",
+    "declaration": true
+  },
+  "include": ["src/**/*.ts", "data/**/*.json"],
+  "exclude": ["node_modules", "dist"]
+}