diff --git a/ccm-apiclient-commons/.gitignore b/ccm-apiclient-commons/.gitignore
index 1502ec233..27c057bb8 100644
--- a/ccm-apiclient-commons/.gitignore
+++ b/ccm-apiclient-commons/.gitignore
@@ -1,3 +1,3 @@
 dist
 node_modules
-
+target
diff --git a/ccm-apiclient-commons/src/main/typescript/ApiClient.ts b/ccm-apiclient-commons/src/main/typescript/ApiClient.ts
index 3c8c51942..3e041203a 100644
--- a/ccm-apiclient-commons/src/main/typescript/ApiClient.ts
+++ b/ccm-apiclient-commons/src/main/typescript/ApiClient.ts
@@ -25,7 +25,7 @@ export interface LibreCcmApiClient {
      */
     post(
         endpoint: string,
-        body: unknown,
+        body: RequestBody,
         searchParams?: Record<string, string>
     ): Promise<ApiResponse>;
     /**
@@ -39,7 +39,7 @@ export interface LibreCcmApiClient {
      */
     put(
         endpoint: string,
-        body: Record<string, unknown>,
+        body: unknown,
         searchParams?: Record<string, string>
     ): Promise<ApiResponse>;
     /**
@@ -72,6 +72,12 @@ export interface LibreCcmApiClient {
     options(endpoint: string): Promise<ApiResponse>;
 }
 
+export type RequestBody =
+    | Record<string, unknown>
+    | ArrayBuffer
+    | string
+    | undefined;
+
 /**
  * The response from the API.
  */
@@ -194,11 +200,22 @@ export class ApiClientFetchImpl implements LibreCcmApiClient {
     }
 
     private buildFetchOptions(
-        method: "get" | "post" | "put" | "delete" | "head" | "options"
+        method: "get" | "post" | "put" | "delete" | "head" | "options",
+        body?: RequestBody
     ): RequestInit {
-        const fetchOptions: RequestInit = {};
-        Object.assign(fetchOptions, this.#fetchOptions);
+        const fetchOptions: RequestInit = {
+            ...this.#fetchOptions,
+        };
         fetchOptions.method = method;
+        if (body) {
+            if (body instanceof ArrayBuffer) {
+                fetchOptions.body = body;
+            } else if (typeof body === "string") {
+                fetchOptions.body = body;
+            } else {
+                fetchOptions.body = JSON.stringify(body);
+            }
+        }
 
         return fetchOptions;
     }
@@ -232,35 +249,151 @@ export class ApiClientFetchImpl implements LibreCcmApiClient {
         }
     }
 
-    post(
+    async post(
         endpoint: string,
-        body: unknown,
+        body: RequestBody,
         searchParams?: Record<string, string>
     ): Promise<ApiResponse> {
-        throw "Not implemented yet.";
+        const url = buildUrl(this.#baseUrl, endpoint, searchParams);
+        try {
+            const response = await fetch(
+                url,
+                this.buildFetchOptions("post", body)
+            );
+            if (response.ok) {
+                return new FetchResponse(response);
+            } else {
+                throw {
+                    status: response.status,
+                    statusText: response.statusText,
+                    method: "get",
+                    message: "API responded with an error.",
+                    url,
+                };
+            }
+        } catch (err) {
+            throw {
+                status: -1,
+                statusText: "n/a",
+                method: "get",
+                message: `Failed to execute get: ${err}`,
+                url,
+            };
+        }
     }
 
-    put(
+    async put(
         endpoint: string,
-        body: unknown,
+        body: RequestBody,
         searchParams?: Record<string, string>
     ): Promise<ApiResponse> {
-        throw "Not implemented yet.";
+        const url = buildUrl(this.#baseUrl, endpoint, searchParams);
+        try {
+            const response = await fetch(
+                url,
+                this.buildFetchOptions("put", body)
+            );
+            if (response.ok) {
+                return new FetchResponse(response);
+            } else {
+                throw {
+                    status: response.status,
+                    statusText: response.statusText,
+                    method: "get",
+                    message: "API responded with an error.",
+                    url,
+                };
+            }
+        } catch (err) {
+            throw {
+                status: -1,
+                statusText: "n/a",
+                method: "get",
+                message: `Failed to execute get: ${err}`,
+                url,
+            };
+        }
     }
 
-    delete(
+    async delete(
         endpoint: string,
         searchParams?: Record<string, string>
     ): Promise<ApiResponse> {
-        throw "Not implemented yet.";
+        const url = buildUrl(this.#baseUrl, endpoint, searchParams);
+        try {
+            const response = await fetch(url, this.buildFetchOptions("delete"));
+            if (response.ok) {
+                return new FetchResponse(response);
+            } else {
+                throw {
+                    status: response.status,
+                    statusText: response.statusText,
+                    method: "get",
+                    message: "API responded with an error.",
+                    url,
+                };
+            }
+        } catch (err) {
+            throw {
+                status: -1,
+                statusText: "n/a",
+                method: "get",
+                message: `Failed to execute get: ${err}`,
+                url,
+            };
+        }
     }
 
-    head(endpoint: string): Promise<ApiResponse> {
-        throw "Not implemented yet.";
+    async head(endpoint: string): Promise<ApiResponse> {
+        const url = buildUrl(this.#baseUrl, endpoint);
+        try {
+            const response = await fetch(url, this.buildFetchOptions("head"));
+            if (response.ok) {
+                return new FetchResponse(response);
+            } else {
+                throw {
+                    status: response.status,
+                    statusText: response.statusText,
+                    method: "get",
+                    message: "API responded with an error.",
+                    url,
+                };
+            }
+        } catch (err) {
+            throw {
+                status: -1,
+                statusText: "n/a",
+                method: "get",
+                message: `Failed to execute get: ${err}`,
+                url,
+            };
+        }
     }
 
-    options(endpoint: string): Promise<ApiResponse> {
-        throw "Not implemented yet.";
+    async options(endpoint: string): Promise<ApiResponse> {
+        const url = buildUrl(this.#baseUrl, endpoint);
+        try {
+            const response = await fetch(url, this.buildFetchOptions("options"));
+            if (response.ok) {
+                return new FetchResponse(response);
+            } else {
+                throw {
+                    status: response.status,
+                    statusText: response.statusText,
+                    method: "get",
+                    message: "API responded with an error.",
+                    url,
+                };
+            }
+        } catch (err) {
+            throw {
+                status: -1,
+                statusText: "n/a",
+                method: "get",
+                message: `Failed to execute get: ${err}`,
+                url,
+            };
+        }
     }
 }