docs: update all documentation for subscription auth, billing tiers, and API key management

packages/sdk-ts/README.md

@@ -13,10 +13,12 @@ npm install agentlens-sdk
 
 ## Quick Start
 
+First, create an account at [agentlens.vectry.tech/register](https://agentlens.vectry.tech/register) and generate an API key in **Settings > API Keys** in the dashboard.
+
 ```typescript
 import { init, TraceBuilder, shutdown } from "agentlens-sdk";
 
-// Initialize the SDK
+// Initialize with the API key from Settings > API Keys
 init({
   apiKey: "your-api-key",
   endpoint: "https://agentlens.vectry.tech/api",
@@ -104,17 +106,31 @@ Pass `InitOptions` to `init()`:
 
 ```typescript
 init({
-  apiKey: "your-api-key",       // Required. Your AgentLens API key.
+  apiKey: "your-api-key",       // Required. Create at Settings > API Keys in the dashboard.
   endpoint: "https://...",      // API endpoint. Defaults to AgentLens cloud.
   maxBatchSize: 100,            // Max items per batch before auto-flush.
   flushInterval: 5000,          // Auto-flush interval in milliseconds.
 });
 ```
 
+You can also set the API key via the `AGENTLENS_API_KEY` environment variable instead of passing it directly.
+
 ## Transport
 
 The SDK ships with `BatchTransport`, which batches payloads and flushes them on an interval or when the batch size threshold is reached. This is used internally by `init()` — you typically do not need to instantiate it directly.
 
+## Billing
+
+Each trace counts as one session for billing. AgentLens cloud offers three tiers:
+
+| Plan | Price | Sessions |
+|------|-------|----------|
+| Free | $0 | 20 sessions/day |
+| Starter | $5/month | 1,000 sessions/month |
+| Pro | $20/month | 100,000 sessions/month |
+
+Manage your subscription in **Settings > Billing**. Self-hosted instances have no session limits.
+
 ## Documentation
 
 Full documentation: [agentlens.vectry.tech/docs/typescript-sdk](https://agentlens.vectry.tech/docs/typescript-sdk)