Linktree's REST API exposes profile management, link CRUD, click analytics, and appearance theming through bearer-token authentication. A structured SDK client matters here because Linktree enforces strict per-minute rate limits on analytics endpoints and returns nested profile objects that benefit from strong typing. These patterns provide a thread-safe singleton, typed error classification, fluent request building for paginated link lists, and test utilities for mocking profile and analytics responses.
LINKTREE_API_KEY environment variable (generated in Linktree admin > Settings > Developer)axios or node-fetch for HTTP transportinterface LinktreeConfig {
apiKey: string;
baseUrl?: string;
timeout?: number;
}
let client: LinktreeClient | null = null;
export function getLinktreeClient(overrides?: Partial<LinktreeConfig>): LinktreeClient {
if (!client) {
const config: LinktreeConfig = {
apiKey: process.env.LINKTREE_API_KEY ?? '',
baseUrl: 'https://api.linktr.ee/v1',
timeout: 10_000,
...overrides,
};
if (!config.apiKey) throw new Error('LINKTREE_API_KEY is required');
client = new LinktreeClient(config);
}
return client;
}
interface LinktreeError { status: number; code: string; detail: string; }
async function safeLinktree<T>(fn: () => Promise<T>): Promise<T> {
try { return await fn(); }
catch (err: any) {
const parsed: LinktreeError = {
status: err.response?.status ?? 500,
code: err.response?.data?.error?.code ?? 'UNKNOWN',
detail: err.response?.data?.error?.message ?? err.message,
};
if (parsed.status === 429) {
const retryAfter = parseInt(err.response?.headers?.['retry-after'] ?? '5', 10);
await new Promise(r => setTimeout(r, retryAfter * 1000));
return fn();
}
if (parsed.status === 401) throw new Error(`Auth failed: ${parsed.detail}`);
throw new Error(`Linktree ${parsed.code} (${parsed.status}): ${parsed.detail}`);
}
}
class LinkQueryBuilder {
private params: Record<string, string> = {};
forProfile(id: string) { this.params.profile_id = id; return this; }
active(only = true) { this.params.is_active = String(only); return this; }
page(cursor: string) { this.params.cursor = cursor; return this; }
limit(n: number) { this.params.limit = String(Math.min(n, 100)); return this; }
build(): URLSearchParams { return new URLSearchParams(this.params); }
}
interface LinktreeProfile { id: string; username: string; tier: 'free' | 'pro' | 'premium'; created_at: string; }
interface LinktreeLink { id: string; title: string; url: string; position: number; is_active: boolean; thumbnail_url?: string; }
interface LinkAnalytics { link_id: string; clicks: number; unique_visitors: number; period: string; }
interface PaginatedLinks { data: LinktreeLink[]; cursor?: string; has_more: boolean; }
type Middleware = (req: RequestInit, next: () => Promise<Response>) => Promise<Response>;
const authMiddleware: Middleware = (req, next) => {
req.headers = { ...req.headers as Record<string, string>, Authorization: `Bearer ${process.env.LINKTREE_API_KEY}` };
return next();
};
const loggingMiddleware: Middleware = async (req, next) => {
const start = Date.now();
const res = await next();
console.log(`[linktree] ${req.method} ${res.status} ${Date.now() - start}ms`);
return res;
};
function mockProfile(overrides?: Partial<LinktreeProfile>): LinktreeProfile {
return { id: 'prof_test_123', username: 'testuser', tier: 'pro', created_at: '2025-01-01T00:00:00Z', ...overrides };
}
function mockLink(overrides?: Partial<LinktreeLink>): LinktreeLink {
return { id: 'link_abc', title: 'My Site', url: 'https://example.com', position: 0, is_active: true, ...overrides };
}
function mockAnalytics(linkId: string): LinkAnalytics {
return { link_id: linkId, clicks: 142, unique_visitors: 98, period: '7d' };
}
| Pattern | When to Use | Example |
|---|---|---|
| Retry with backoff | 429 rate limit on analytics endpoints | Parse Retry-After header, wait, retry once |
| Auth refresh | 401 on any endpoint | Re-fetch API key from vault, rebuild client singleton |
| Graceful degrade | Analytics endpoint down | Return cached click counts, log warning |
| Validation guard | Creating links with invalid URLs | Check URL format before API call, throw typed error |
| Idempotency check | Duplicate link creation | Query existing links by URL before POST |
Apply in linktree-core-workflow-a.