How to Integrate Lovable with Basecamp

Basecamp supports two authentication methods: OAuth2 for user-facing applications where individual users authorize access, and personal access tokens for server-to-server integrations. For a Lovable integration where your app accesses your own Basecamp account, a personal access token is the simpler choice. To generate one, visit launchpad.37signals.com — this is the 37signals (Basecamp's parent company) identity platform that manages credentials across Basecamp, Hey, and other 37signals products. Click your account name in the top-right corner, select 'My profile', and scroll to the 'API Tokens' section. Click 'Generate a new token', provide a name like 'Lovable Integration', and copy the token immediately. You'll also need your Basecamp account ID — log into Basecamp at 3.basecamp.com and note the first number in the URL path: 3.basecamp.com/XXXXXXXXX — that's your account ID. With both values ready, open your Lovable project and click the '+' icon to access the Cloud tab. Navigate to the Secrets section and add two secrets: BASECAMP_ACCESS_TOKEN with your token value, and BASECAMP_ACCOUNT_ID with your numeric account ID. Both will be used by your Edge Function to construct API request URLs. Lovable's security infrastructure keeps these encrypted and isolated from all client-side code.

The Basecamp API v3 uses a REST architecture with an important structural pattern: every resource URL is scoped under your account ID as /3/ACCOUNT_ID/. Projects are listed at /3/{accountId}/projects.json. Each project has a 'dock' — an array of tool objects where each tool has a 'url' field pointing to its resource endpoint. To fetch to-do lists, you find the project dock entry where 'name' equals 'todoset' and use its URL. This indirection means your Edge Function needs to handle multi-step navigation for some operations. The following Edge Function scaffolds all the common operations: listing projects, fetching a project's dock, getting to-do lists, getting to-do items, creating to-dos, fetching messages, and posting messages. It uses an action-based routing pattern where the frontend specifies what operation to perform and passes the relevant resource URLs or IDs. All requests include the required User-Agent header (Basecamp's API requires identifying your app) and the Bearer token Authorization header.

1// supabase/functions/basecamp-proxy/index.ts
2import { serve } from "https://deno.land/std@0.168.0/http/server.ts";
3
4const corsHeaders = {
5  "Access-Control-Allow-Origin": "*",
6  "Access-Control-Allow-Headers": "authorization, x-client-info, apikey, content-type",
7};
8
9serve(async (req) => {
10  if (req.method === "OPTIONS") {
11    return new Response("ok", { headers: corsHeaders });
12  }
13
14  const token = Deno.env.get("BASECAMP_ACCESS_TOKEN");
15  const accountId = Deno.env.get("BASECAMP_ACCOUNT_ID");
16  if (!token || !accountId) {
17    return new Response(JSON.stringify({ error: "Basecamp credentials not configured" }), {
18      status: 500,
19      headers: { ...corsHeaders, "Content-Type": "application/json" },
20    });
21  }
22
23  const baseUrl = `https://3.basecampapi.com/${accountId}`;
24  const authHeaders = {
25    Authorization: `Bearer ${token}`,
26    "User-Agent": "Lovable Basecamp Integration (contact@yourapp.com)",
27    "Content-Type": "application/json",
28  };
29
30  const { action, params = {} } = await req.json();
31  let response;
32
33  switch (action) {
34    case "list_projects":
35      response = await fetch(`${baseUrl}/projects.json`, { headers: authHeaders });
36      break;
37    case "get_project":
38      response = await fetch(`${baseUrl}/projects/${params.projectId}.json`, { headers: authHeaders });
39      break;
40    case "get_todolists": {
41      // First get todoset URL from project dock
42      const proj = await fetch(`${baseUrl}/projects/${params.projectId}.json`, { headers: authHeaders });
43      const projData = await proj.json();
44      const todoset = projData.dock?.find((d: { name: string }) => d.name === "todoset");
45      if (!todoset) return new Response(JSON.stringify({ error: "No todoset found" }), { status: 404, headers: { ...corsHeaders, "Content-Type": "application/json" } });
46      response = await fetch(`${todoset.url}/todolists.json`, { headers: authHeaders });
47      break;
48    }
49    case "get_todos":
50      response = await fetch(`${params.todolistUrl}/todos.json`, { headers: authHeaders });
51      break;
52    case "create_todo":
53      response = await fetch(`${params.todolistUrl}/todos.json`, {
54        method: "POST",
55        headers: authHeaders,
56        body: JSON.stringify({ content: params.content, due_on: params.dueOn, assignee_ids: params.assigneeIds || [] }),
57      });
58      break;
59    case "list_messages": {
60      const proj2 = await fetch(`${baseUrl}/projects/${params.projectId}.json`, { headers: authHeaders });
61      const proj2Data = await proj2.json();
62      const msgBoard = proj2Data.dock?.find((d: { name: string }) => d.name === "message_board");
63      if (!msgBoard) return new Response(JSON.stringify({ error: "No message board found" }), { status: 404, headers: { ...corsHeaders, "Content-Type": "application/json" } });
64      response = await fetch(`${msgBoard.url}/messages.json`, { headers: authHeaders });
65      break;
66    }
67    default:
68      return new Response(JSON.stringify({ error: `Unknown action: ${action}` }), {
69        status: 400,
70        headers: { ...corsHeaders, "Content-Type": "application/json" },
71      });
72  }
73
74  const data = await response.json();
75  return new Response(JSON.stringify(data), {
76    status: response.status,
77    headers: { ...corsHeaders, "Content-Type": "application/json" },
78  });
79});

With the Edge Function deployed, you can build a project overview page that displays Basecamp project data in a custom layout. The key is navigating the dock structure correctly — each project's dock array tells you which tools are enabled and provides the direct API URL for each tool, so you don't need to construct URLs manually after the initial project fetch. The most useful single-page view for most Lovable apps is a project dashboard showing open to-dos, recent messages, and upcoming schedule entries. This gives a complete picture of project status without requiring users to click between multiple Basecamp tools. The following prompt generates a tabbed dashboard component that fetches and displays data from the three most common Basecamp tools.

Reading Basecamp data is only half the integration — most apps also need to write back to Basecamp. Creating a to-do item requires the to-do list URL (obtained from the project dock → todoset → todolists response), the content string, an optional due date in YYYY-MM-DD format, and optional assignee IDs. Assignee IDs are numeric Basecamp person IDs, which you can fetch from the project's people endpoint. Posting a message to the message board is similarly straightforward: POST to the message board URL (from the dock) with a subject, content (HTML allowed), and optional category. For complex workflows where you need to create to-dos in response to events in other systems — for example, creating a Basecamp to-do when a Supabase record changes — RapidDev's team can help architect a robust event-driven pipeline that keeps your Basecamp content synchronized with your app's data model.