diff --git a/packages/client/package.json b/packages/client/package.json
new file mode 100644
index 0000000..495aac0
--- /dev/null
+++ b/packages/client/package.json
@@ -0,0 +1,21 @@
+{
+  "name": "@crate/client",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "exports": {
+    ".": "./src/index.ts"
+  },
+  "scripts": {
+    "generate": "bun scripts/generate.ts",
+    "check": "bun scripts/generate.ts --check"
+  },
+  "dependencies": {
+    "openapi-fetch": "0.17.0"
+  },
+  "devDependencies": {
+    "@types/node": "26.4.0",
+    "openapi-typescript": "7.13.0",
+    "typescript": "6.0.3"
+  }
+}
diff --git a/packages/client/scripts/generate.test.ts b/packages/client/scripts/generate.test.ts
new file mode 100644
index 0000000..47845ce
--- /dev/null
+++ b/packages/client/scripts/generate.test.ts
@@ -0,0 +1,43 @@
+import { spawnSync } from "node:child_process"
+import { mkdtemp, readFile, writeFile } from "node:fs/promises"
+import { tmpdir } from "node:os"
+import { join } from "node:path"
+import { fileURLToPath } from "node:url"
+import { expect, it } from "vitest"
+
+it("generates typed binary requests and detects contract drift", async () => {
+  const directory = await mkdtemp(join(tmpdir(), "crate-typegen-test-"))
+  const schema = join(directory, "openapi.json")
+  const output = join(directory, "schema.ts")
+  await writeFile(
+    schema,
+    JSON.stringify({
+      openapi: "3.0.3",
+      info: { title: "Fixture", version: "1" },
+      paths: {
+        "/upload": {
+          post: {
+            operationId: "upload",
+            requestBody: {
+              required: true,
+              content: {
+                "application/octet-stream": { schema: { type: "string", format: "binary" } },
+              },
+            },
+            responses: { "204": { description: "Stored" } },
+          },
+        },
+      },
+    }),
+  )
+  const generator = fileURLToPath(new URL("./generate.ts", import.meta.url))
+  const generate = (...args: string[]) =>
+    spawnSync("bun", [generator, schema, output, ...args], { encoding: "utf8" })
+  expect(generate().status).toBe(0)
+  expect(await readFile(output, "utf8")).toContain('"application/octet-stream": Blob')
+  expect(generate("--check").status).toBe(0)
+  await writeFile(output, "stale output")
+  const stale = generate("--check")
+  expect(stale.status).not.toBe(0)
+  expect(stale.stderr).toContain("client contract is stale")
+})
diff --git a/packages/client/scripts/generate.ts b/packages/client/scripts/generate.ts
new file mode 100644
index 0000000..5504bd0
--- /dev/null
+++ b/packages/client/scripts/generate.ts
@@ -0,0 +1,29 @@
+import { readFile, writeFile } from "node:fs/promises"
+import { resolve } from "node:path"
+import { pathToFileURL } from "node:url"
+import openapiTS, { astToString } from "openapi-typescript"
+import ts from "typescript"
+
+const arguments_ = process.argv.slice(2).filter((value) => value !== "--check")
+const input = arguments_[0]
+  ? pathToFileURL(resolve(arguments_[0]))
+  : new URL("../openapi.json", import.meta.url)
+const output = arguments_[1]
+  ? pathToFileURL(resolve(arguments_[1]))
+  : new URL("../src/schema.ts", import.meta.url)
+const ast = await openapiTS(input, {
+  alphabetize: true,
+  transform(schema) {
+    if (schema.type === "string" && schema.format === "binary") {
+      return ts.factory.createTypeReferenceNode("Blob")
+    }
+  },
+})
+const generated = `// Generated from the Rust server's OpenAPI contract. Do not edit.\n${astToString(ast)}`
+if (process.argv.includes("--check")) {
+  if ((await readFile(output, "utf8")) !== generated) {
+    throw new Error("TypeScript client contract is stale. Run bun run generate:api.")
+  }
+} else {
+  await writeFile(output, generated)
+}
diff --git a/packages/client/tsconfig.json b/packages/client/tsconfig.json
new file mode 100644
index 0000000..2be06f5
--- /dev/null
+++ b/packages/client/tsconfig.json
@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "composite": true,
+    "strict": true,
+    "lib": ["ES2022", "DOM", "DOM.Iterable"]
+  },
+  "include": ["src", "scripts", "../../scripts/generate-api.ts"]
+}