diff --git a/api/routes/_.context.ts b/api/routes/_.context.ts
index 7ae9a0c..2bbd799 100644
--- a/api/routes/_.context.ts
+++ b/api/routes/_.context.ts
@@ -8,4 +8,179 @@
  *
  * See https://counterfact.dev/docs/usage.html#working-with-state-the-codecontextcode-object-and-codecontexttscode
  */
-export class Context {}
+
+import type { Pet } from "../types/components/schemas/Pet.js";
+import type { User } from "../types/components/schemas/User.js";
+import type { Order } from "../types/components/schemas/Order.js";
+
+export class Context {
+  pets: Pet[] = [
+    {
+      id: 1,
+      name: "Buddy",
+      category: { id: 1, name: "Dogs" },
+      photoUrls: ["https://example.com/buddy.jpg"],
+      tags: [{ id: 1, name: "friendly" }],
+      status: "available",
+    },
+    {
+      id: 2,
+      name: "Whiskers",
+      category: { id: 2, name: "Cats" },
+      photoUrls: ["https://example.com/whiskers.jpg"],
+      tags: [{ id: 2, name: "indoor" }],
+      status: "available",
+    },
+    {
+      id: 3,
+      name: "Goldie",
+      category: { id: 3, name: "Fish" },
+      photoUrls: ["https://example.com/goldie.jpg"],
+      tags: [],
+      status: "pending",
+    },
+    {
+      id: 4,
+      name: "Max",
+      category: { id: 1, name: "Dogs" },
+      photoUrls: ["https://example.com/max.jpg"],
+      tags: [{ id: 3, name: "trained" }],
+      status: "sold",
+    },
+  ];
+
+  users: User[] = [
+    {
+      id: 1,
+      username: "user1",
+      firstName: "John",
+      lastName: "Doe",
+      email: "john@example.com",
+      password: "password123",
+      phone: "555-1234",
+      userStatus: 1,
+    },
+    {
+      id: 2,
+      username: "jane_smith",
+      firstName: "Jane",
+      lastName: "Smith",
+      email: "jane@example.com",
+      password: "secret456",
+      phone: "555-5678",
+      userStatus: 1,
+    },
+  ];
+
+  orders: Order[] = [
+    {
+      id: 1,
+      petId: 1,
+      quantity: 1,
+      shipDate: "2024-01-15T10:00:00Z",
+      status: "placed",
+      complete: false,
+    },
+    {
+      id: 2,
+      petId: 4,
+      quantity: 1,
+      shipDate: "2024-01-10T08:00:00Z",
+      status: "delivered",
+      complete: true,
+    },
+  ];
+
+  private nextPetId = 5;
+  private nextUserId = 3;
+  private nextOrderId = 3;
+
+  addPet(pet: Pet): Pet {
+    const newPet = { ...pet, id: this.nextPetId++ };
+    this.pets.push(newPet);
+    return newPet;
+  }
+
+  updatePet(pet: Pet): Pet | undefined {
+    const index = this.pets.findIndex((p) => p.id === pet.id);
+    if (index === -1) return undefined;
+    this.pets[index] = pet;
+    return pet;
+  }
+
+  getPetById(id: number): Pet | undefined {
+    return this.pets.find((p) => p.id === id);
+  }
+
+  deletePet(id: number): boolean {
+    const index = this.pets.findIndex((p) => p.id === id);
+    if (index === -1) return false;
+    this.pets.splice(index, 1);
+    return true;
+  }
+
+  findPetsByStatus(status: "available" | "pending" | "sold"): Pet[] {
+    return this.pets.filter((p) => p.status === status);
+  }
+
+  findPetsByTags(tags: string[]): Pet[] {
+    return this.pets.filter((p) =>
+      p.tags?.some((t) => t.name !== undefined && tags.includes(t.name)),
+    );
+  }
+
+  addUser(user: User): User {
+    const newUser = { ...user, id: this.nextUserId++ };
+    this.users.push(newUser);
+    return newUser;
+  }
+
+  getUserByUsername(username: string): User | undefined {
+    return this.users.find((u) => u.username === username);
+  }
+
+  updateUser(username: string, user: User): User | undefined {
+    const index = this.users.findIndex((u) => u.username === username);
+    if (index === -1) return undefined;
+    this.users[index] = { ...user, username };
+    return this.users[index];
+  }
+
+  deleteUser(username: string): boolean {
+    const index = this.users.findIndex((u) => u.username === username);
+    if (index === -1) return false;
+    this.users.splice(index, 1);
+    return true;
+  }
+
+  placeOrder(order: Order): Order {
+    const newOrder = { ...order, id: this.nextOrderId++ };
+    this.orders.push(newOrder);
+    return newOrder;
+  }
+
+  getOrderById(id: number): Order | undefined {
+    return this.orders.find((o) => o.id === id);
+  }
+
+  deleteOrder(id: number): boolean {
+    const index = this.orders.findIndex((o) => o.id === id);
+    if (index === -1) return false;
+    this.orders.splice(index, 1);
+    return true;
+  }
+
+  getInventory(): { [key: string]: number } {
+    const inventory: { [key: string]: number } = {
+      available: 0,
+      pending: 0,
+      sold: 0,
+    };
+    for (const pet of this.pets) {
+      if (pet.status) {
+        inventory[pet.status] = (inventory[pet.status] ?? 0) + 1;
+      }
+    }
+    return inventory;
+  }
+}
diff --git a/api/routes/pet.ts b/api/routes/pet.ts
index a7e23a5..8da9bd8 100644
--- a/api/routes/pet.ts
+++ b/api/routes/pet.ts
@@ -1,10 +1,18 @@
 import type { updatePet } from "../types/paths/pet.types.js";
 import type { addPet } from "../types/paths/pet.types.js";
 
-export const PUT: updatePet = async ($) => {
-  return $.response[200].random();
+export const PUT: updatePet = ($) => {
+  if (!$.body.id) {
+    return $.response[400];
+  }
+  const updated = $.context.updatePet($.body);
+  if (!updated) {
+    return $.response[404];
+  }
+  return $.response[200].json(updated);
 };
 
-export const POST: addPet = async ($) => {
-  return $.response[200].random();
+export const POST: addPet = ($) => {
+  const pet = $.context.addPet($.body);
+  return $.response[200].json(pet);
 };
diff --git a/api/routes/pet/findByStatus.ts b/api/routes/pet/findByStatus.ts
index 8b9195f..2a4567e 100644
--- a/api/routes/pet/findByStatus.ts
+++ b/api/routes/pet/findByStatus.ts
@@ -1,5 +1,6 @@
 import type { findPetsByStatus } from "../../types/paths/pet/findByStatus.types.js";
 
-export const GET: findPetsByStatus = async ($) => {
-  return $.response[200].random();
+export const GET: findPetsByStatus = ($) => {
+  const pets = $.context.findPetsByStatus($.query.status);
+  return $.response[200].json(pets);
 };
diff --git a/api/routes/pet/findByTags.ts b/api/routes/pet/findByTags.ts
index 378b273..9db1b5c 100644
--- a/api/routes/pet/findByTags.ts
+++ b/api/routes/pet/findByTags.ts
@@ -1,5 +1,6 @@
 import type { findPetsByTags } from "../../types/paths/pet/findByTags.types.js";
 
-export const GET: findPetsByTags = async ($) => {
-  return $.response[200].random();
+export const GET: findPetsByTags = ($) => {
+  const pets = $.context.findPetsByTags($.query.tags);
+  return $.response[200].json(pets);
 };
diff --git a/api/routes/pet/{petId}.ts b/api/routes/pet/{petId}.ts
index 4f53319..1fc4187 100644
--- a/api/routes/pet/{petId}.ts
+++ b/api/routes/pet/{petId}.ts
@@ -2,14 +2,36 @@ import type { getPetById } from "../../types/paths/pet/{petId}.types.js";
 import type { updatePetWithForm } from "../../types/paths/pet/{petId}.types.js";
 import type { deletePet } from "../../types/paths/pet/{petId}.types.js";
 
-export const GET: getPetById = async ($) => {
-  return $.response[200].random();
+export const GET: getPetById = ($) => {
+  const pet = $.context.getPetById($.path.petId);
+  if (!pet) {
+    return $.response[404];
+  }
+  return $.response[200].json(pet);
 };
 
-export const POST: updatePetWithForm = async ($) => {
-  return $.response[200].random();
+export const POST: updatePetWithForm = ($) => {
+  const pet = $.context.getPetById($.path.petId);
+  if (!pet) {
+    return $.response[400];
+  }
+  const updated = $.context.updatePet({
+    ...pet,
+    ...($.query.name !== undefined ? { name: $.query.name } : {}),
+    ...($.query.status !== undefined
+      ? { status: $.query.status as "available" | "pending" | "sold" }
+      : {}),
+  });
+  if (!updated) {
+    return $.response[400];
+  }
+  return $.response[200].json(updated);
 };
 
-export const DELETE: deletePet = async ($) => {
+export const DELETE: deletePet = ($) => {
+  const deleted = $.context.deletePet($.path.petId);
+  if (!deleted) {
+    return $.response[400];
+  }
   return $.response[200];
 };
diff --git a/api/routes/pet/{petId}/uploadImage.ts b/api/routes/pet/{petId}/uploadImage.ts
index f3262ba..fd5de1c 100644
--- a/api/routes/pet/{petId}/uploadImage.ts
+++ b/api/routes/pet/{petId}/uploadImage.ts
@@ -1,5 +1,13 @@
 import type { uploadFile } from "../../../types/paths/pet/{petId}/uploadImage.types.js";
 
-export const POST: uploadFile = async ($) => {
-  return $.response[200].random();
+export const POST: uploadFile = ($) => {
+  const pet = $.context.getPetById($.path.petId);
+  if (!pet) {
+    return $.response[404];
+  }
+  return $.response[200].json({
+    code: 200,
+    type: "unknown",
+    message: `File uploaded for pet ${$.path.petId}`,
+  });
 };
diff --git a/api/routes/store/inventory.ts b/api/routes/store/inventory.ts
index 5f57b3a..24e74bb 100644
--- a/api/routes/store/inventory.ts
+++ b/api/routes/store/inventory.ts
@@ -1,5 +1,6 @@
 import type { getInventory } from "../../types/paths/store/inventory.types.js";
 
-export const GET: getInventory = async ($) => {
-  return $.response[200].random();
+export const GET: getInventory = ($) => {
+  const inventory = $.context.getInventory();
+  return $.response[200].json(inventory);
 };
diff --git a/api/routes/store/order.ts b/api/routes/store/order.ts
index 49e7097..2388046 100644
--- a/api/routes/store/order.ts
+++ b/api/routes/store/order.ts
@@ -1,5 +1,6 @@
 import type { placeOrder } from "../../types/paths/store/order.types.js";
 
-export const POST: placeOrder = async ($) => {
-  return $.response[200].random();
+export const POST: placeOrder = ($) => {
+  const order = $.context.placeOrder($.body);
+  return $.response[200].json(order);
 };
diff --git a/api/routes/store/order/{orderId}.ts b/api/routes/store/order/{orderId}.ts
index 1604417..660f051 100644
--- a/api/routes/store/order/{orderId}.ts
+++ b/api/routes/store/order/{orderId}.ts
@@ -1,10 +1,18 @@
 import type { getOrderById } from "../../../types/paths/store/order/{orderId}.types.js";
 import type { deleteOrder } from "../../../types/paths/store/order/{orderId}.types.js";
 
-export const GET: getOrderById = async ($) => {
-  return $.response[200].random();
+export const GET: getOrderById = ($) => {
+  const order = $.context.getOrderById($.path.orderId);
+  if (!order) {
+    return $.response[404];
+  }
+  return $.response[200].json(order);
 };
 
-export const DELETE: deleteOrder = async ($) => {
+export const DELETE: deleteOrder = ($) => {
+  const deleted = $.context.deleteOrder($.path.orderId);
+  if (!deleted) {
+    return $.response[404];
+  }
   return $.response[200];
 };
diff --git a/api/routes/user.ts b/api/routes/user.ts
index da9a0a4..c1efc68 100644
--- a/api/routes/user.ts
+++ b/api/routes/user.ts
@@ -1,5 +1,6 @@
 import type { createUser } from "../types/paths/user.types.js";
 
-export const POST: createUser = async ($) => {
-  return $.response[200].random();
+export const POST: createUser = ($) => {
+  const user = $.context.addUser($.body);
+  return $.response[200].json(user);
 };
diff --git a/api/routes/user/createWithList.ts b/api/routes/user/createWithList.ts
index 72c66a0..0c30fdc 100644
--- a/api/routes/user/createWithList.ts
+++ b/api/routes/user/createWithList.ts
@@ -1,5 +1,7 @@
 import type { createUsersWithListInput } from "../../types/paths/user/createWithList.types.js";
 
-export const POST: createUsersWithListInput = async ($) => {
-  return $.response[200].random();
+export const POST: createUsersWithListInput = ($) => {
+  const users = $.body.map((user) => $.context.addUser(user));
+  // The OpenAPI spec returns a single User on 200; return the first created user
+  return $.response[200].json(users[0]);
 };
diff --git a/api/routes/user/login.ts b/api/routes/user/login.ts
index 27ab891..fc86e7a 100644
--- a/api/routes/user/login.ts
+++ b/api/routes/user/login.ts
@@ -1,5 +1,11 @@
 import type { loginUser } from "../../types/paths/user/login.types.js";
 
-export const GET: loginUser = async ($) => {
-  return $.response[200].random();
+export const GET: loginUser = ($) => {
+  const user = $.context.users.find(
+    (u) => u.username === $.query.username && u.password === $.query.password,
+  );
+  if (!user) {
+    return $.response[400];
+  }
+  return $.response[200].json(`Logged in as ${user.username}`);
 };
diff --git a/api/routes/user/logout.ts b/api/routes/user/logout.ts
index 1ce507e..5ad2b80 100644
--- a/api/routes/user/logout.ts
+++ b/api/routes/user/logout.ts
@@ -1,5 +1,5 @@
 import type { logoutUser } from "../../types/paths/user/logout.types.js";
 
-export const GET: logoutUser = async ($) => {
+export const GET: logoutUser = ($) => {
   return $.response[200];
 };
diff --git a/api/routes/user/{username}.ts b/api/routes/user/{username}.ts
index 9064fa5..5e7f655 100644
--- a/api/routes/user/{username}.ts
+++ b/api/routes/user/{username}.ts
@@ -2,14 +2,26 @@ import type { getUserByName } from "../../types/paths/user/{username}.types.js";
 import type { updateUser } from "../../types/paths/user/{username}.types.js";
 import type { deleteUser } from "../../types/paths/user/{username}.types.js";
 
-export const GET: getUserByName = async ($) => {
-  return $.response[200].random();
+export const GET: getUserByName = ($) => {
+  const user = $.context.getUserByUsername($.path.username);
+  if (!user) {
+    return $.response[404];
+  }
+  return $.response[200].json(user);
 };
 
-export const PUT: updateUser = async ($) => {
+export const PUT: updateUser = ($) => {
+  const updated = $.context.updateUser($.path.username, $.body);
+  if (!updated) {
+    return $.response[404];
+  }
   return $.response[200];
 };
 
-export const DELETE: deleteUser = async ($) => {
+export const DELETE: deleteUser = ($) => {
+  const deleted = $.context.deleteUser($.path.username);
+  if (!deleted) {
+    return $.response[404];
+  }
   return $.response[200];
 };