SDK API Reference

This page documents all exported functions, types, and interfaces in vij-sdk.

Functions

init()

Initialize the VIJ SDK with configuration options. Must be called before using other SDK functions.

init(options: InitOptions): void

InitOptions

required

Configuration object for the SDK. See Configuration Guide for detailed documentation.

Example:

import { init } from "vij-sdk";

init({
  endpoint: "https://vij.example.com/api/logs",
  appId: "my-app",
  environment: "production",
  batch: true,
  maxBatchSize: 20,
  flushIntervalMs: 5000,
  maxQueueSize: 100,
  metadata: {
    version: "1.0.0"
  }
});

Call init() once at application startup, before any other VIJ functions. Calling it multiple times will reinitialize the SDK and may cause data loss.

captureException()

Capture and send an error to VIJ Admin.

captureException(
  error: Error,
  metadata?: Record<string, any>,
  severity?: Severity
): void

Error

required

The error object to capture. Must have name, message, and stack properties.

Record<string, any>

Optional metadata to attach to this error. Merged with global metadata from init().

Severity

default:"error"

Severity level: "error", "warning", or "info".

Example:

import { captureException } from "vij-sdk";

try {
  throw new Error("Payment processing failed");
} catch (error) {
  captureException(error, {
    userId: "user-123",
    orderId: "order-456",
    amount: 99.99
  }, "error");
}

Returns: void

captureMessage()

Capture and send a custom log message to VIJ Admin.

captureMessage(
  message: string,
  metadata?: Record<string, any>,
  severity?: Severity
): void

string

required

The log message to capture.

Record<string, any>

Optional metadata to attach to this message.

Severity

default:"info"

Severity level: "error", "warning", or "info".

Example:

import { captureMessage } from "vij-sdk";

captureMessage("User logged in", {
  userId: "user-123",
  loginMethod: "oauth",
  timestamp: Date.now()
}, "info");

Returns: void

flush()

Immediately flush all queued logs to the server, bypassing batch settings.

flush(): Promise<void>

Example:

import { flush } from "vij-sdk";

// Ensure all logs are sent before page unload
window.addEventListener("beforeunload", async () => {
  await flush();
});

Returns: Promise<void> - Resolves when all logs are sent

Useful for ensuring logs are sent before page navigation, process exit, or application shutdown.

setMetadata()

Update global metadata that will be attached to all future logs.

setMetadata(metadata: Record<string, any>): void

Record<string, any>

required

Metadata object to merge with existing global metadata.

Example:

import { setMetadata } from "vij-sdk";

// Set initial metadata
init({
  endpoint: "...",
  appId: "...",
  environment: "production",
  metadata: { version: "1.0.0" }
});

// Update metadata after user login
function onUserLogin(user) {
  setMetadata({
    userId: user.id,
    userEmail: user.email,
    userPlan: user.plan
  });
}

// All subsequent logs will include user information

Returns: void

Metadata set via setMetadata() is merged with metadata passed to init(). Later values override earlier ones.

clearMetadata()

Remove specific keys from global metadata.

clearMetadata(keys: string[]): void

string[]

required

Array of metadata keys to remove.

Example:

import { setMetadata, clearMetadata } from "vij-sdk";

// Set user metadata on login
setMetadata({ userId: "user-123", userEmail: "user@example.com" });

// Clear user metadata on logout
clearMetadata(["userId", "userEmail"]);

Returns: void

getMetadata()

Retrieve the current global metadata object.

getMetadata(): Record<string, any>

Example:

import { getMetadata } from "vij-sdk";

const currentMetadata = getMetadata();
console.log(currentMetadata);
// { version: "1.0.0", userId: "user-123" }

Returns: Record<string, any> - Current global metadata

Types

InitOptions

Configuration options for the init() function.

interface InitOptions {
  endpoint: string;
  appId: string;
  environment: string;
  batch?: boolean;
  maxBatchSize?: number;
  flushIntervalMs?: number;
  maxQueueSize?: number;
  metadata?: Record<string, any>;
}

string

required

VIJ Admin API endpoint URL (e.g., https://vij.example.com/api/logs)

string

required

Unique identifier for your application

string

required

Environment name (e.g., production, staging, development)

boolean

default:"true"

Enable batching of logs

number

default:"10"

Maximum logs per batch (1-100)

number

default:"5000"

Batch flush interval in milliseconds (1000-60000)

number

default:"100"

Maximum queue size before dropping old logs (10-1000)

Record<string, any>

default:"{}"

Global metadata attached to all logs

Example:

import { type InitOptions } from "vij-sdk";

const config: InitOptions = {
  endpoint: process.env.VIJ_ENDPOINT!,
  appId: "my-app",
  environment: process.env.NODE_ENV,
  batch: true,
  maxBatchSize: 20,
  flushIntervalMs: 5000,
  maxQueueSize: 100,
  metadata: {
    version: "1.0.0",
    region: "us-east-1"
  }
};

Severity

Severity level for errors and messages.

type Severity = "error" | "warning" | "info";

Values:

"error" - Critical errors requiring immediate attention
"warning" - Non-critical issues that should be investigated
"info" - Informational logs for tracking behavior

Example:

import { captureException, type Severity } from "vij-sdk";

function logError(error: Error, level: Severity) {
  captureException(error, {}, level);
}

logError(new Error("Critical failure"), "error");
logError(new Error("Deprecated API used"), "warning");

LogEntry

Structure of a log entry sent to VIJ Admin.

interface LogEntry {
  message: string;
  name: string;
  stack: string;
  severity: Severity;
  timestamp: string;
  appId: string;
  environment: string;
  metadata: Record<string, any>;
  context: BrowserContext | NodeContext;
}

string

Error message or custom log message

string

Error name (e.g., Error, TypeError, CustomError)

string

Stack trace of the error

Severity

Severity level: error, warning, or info

string

ISO 8601 timestamp when the error was captured

string

Application identifier from init()

string

Environment name from init()

Record<string, any>

Merged global and per-error metadata

BrowserContext | NodeContext

Automatically collected contextual information

You don’t create LogEntry objects directly. The SDK generates them automatically when you call captureException() or captureMessage().

BrowserContext

Contextual information collected in browser environments.

interface BrowserContext {
  viewport: {
    width: number;
    height: number;
  };
  screen: {
    width: number;
    height: number;
    colorDepth: number;
  };
  browser: {
    userAgent: string;
    language: string;
    platform: string;
    cookieEnabled: boolean;
    doNotTrack: string | null;
  };
  network?: {
    effectiveType: string;
    downlink: number;
    rtt: number;
  };
}

Example:

{
  "viewport": { "width": 1920, "height": 1080 },
  "screen": { "width": 1920, "height": 1080, "colorDepth": 24 },
  "browser": {
    "userAgent": "Mozilla/5.0...",
    "language": "en-US",
    "platform": "MacIntel",
    "cookieEnabled": true,
    "doNotTrack": "1"
  },
  "network": {
    "effectiveType": "4g",
    "downlink": 10,
    "rtt": 50
  }
}

NodeContext

Contextual information collected in Node.js environments.

interface NodeContext {
  process: {
    pid: number;
    platform: string;
    arch: string;
    nodeVersion: string;
    uptime: number;
    memory: {
      rss: number;
      heapTotal: number;
      heapUsed: number;
      external: number;
    };
  };
}

Example:

{
  "process": {
    "pid": 12345,
    "platform": "linux",
    "arch": "x64",
    "nodeVersion": "v20.0.0",
    "uptime": 3600,
    "memory": {
      "rss": 50000000,
      "heapTotal": 30000000,
      "heapUsed": 20000000,
      "external": 1000000
    }
  }
}

Advanced Usage

Manual Queue Management

import { captureException, flush } from "vij-sdk";

// Capture errors
captureException(error1, { feature: "checkout" });
captureException(error2, { feature: "payment" });

// Manually flush queue before critical operation
await flush();

// Continue with critical operation
await criticalOperation();

Dynamic Metadata Updates

import { setMetadata, clearMetadata, captureException } from "vij-sdk";

// User logs in
function onLogin(user) {
  setMetadata({
    userId: user.id,
    userEmail: user.email,
    userRole: user.role,
    loginTime: new Date().toISOString()
  });
}

// User logs out
function onLogout() {
  clearMetadata(["userId", "userEmail", "userRole", "loginTime"]);
}

// Feature flag changes
function onFeatureFlagChange(flags) {
  setMetadata({ featureFlags: flags });
}

TypeScript Integration

import {
  init,
  captureException,
  captureMessage,
  type InitOptions,
  type Severity,
  type LogEntry
} from "vij-sdk";

// Type-safe configuration
const config: InitOptions = {
  endpoint: process.env.VIJ_ENDPOINT!,
  appId: "my-ts-app",
  environment: process.env.NODE_ENV as string,
  batch: true,
  maxBatchSize: 20,
  metadata: {
    version: "1.0.0"
  }
};

init(config);

// Type-safe error capture
function handleError(error: Error, severity: Severity = "error") {
  captureException(error, {
    timestamp: new Date().toISOString(),
    handled: true
  }, severity);
}

// Custom error class
class ValidationError extends Error {
  constructor(
    message: string,
    public field: string,
    public value: any
  ) {
    super(message);
    this.name = "ValidationError";
  }
}

try {
  throw new ValidationError("Invalid email", "email", "invalid@");
} catch (error) {
  if (error instanceof ValidationError) {
    captureException(error, {
      field: error.field,
      value: error.value
    }, "warning");
  }
}

React Integration

import { captureException, setMetadata } from "vij-sdk";
import { useEffect } from "react";

function App() {
  useEffect(() => {
    // Update metadata when user changes
    setMetadata({
      userId: currentUser?.id,
      userRole: currentUser?.role
    });
  }, [currentUser]);

  return <YourApp />;
}

// Error boundary
class ErrorBoundary extends React.Component {
  componentDidCatch(error: Error, errorInfo: React.ErrorInfo) {
    captureException(error, {
      componentStack: errorInfo.componentStack,
      route: window.location.pathname
    });
  }

  render() {
    return this.props.children;
  }
}

Express Integration

import express from "express";
import { captureException, setMetadata } from "vij-sdk";

const app = express();

// Attach request context to all errors
app.use((req, res, next) => {
  res.locals.requestId = generateRequestId();
  next();
});

// Error handler
app.use((err: Error, req: express.Request, res: express.Response, next: express.NextFunction) => {
  captureException(err, {
    requestId: res.locals.requestId,
    url: req.originalUrl,
    method: req.method,
    userId: req.user?.id,
    ip: req.ip
  });

  res.status(500).json({ error: "Internal server error" });
});

Best Practices

Initialize once at startup

Call init() once when your application starts, before any other code:

// Good - at app entry point
import { init } from "vij-sdk";
init({ /* config */ });

// Then start your app
startApp();

Use TypeScript for type safety

Import types for better IDE support and compile-time checking:

import { init, type InitOptions, type Severity } from "vij-sdk";

const config: InitOptions = { /* ... */ };
const level: Severity = "error";

Flush before critical operations

Ensure logs are sent before page unload, process exit, or deployments:

window.addEventListener("beforeunload", () => flush());
process.on("SIGTERM", async () => {
  await flush();
  process.exit(0);
});

Use metadata for context, not in messages

// Good
captureMessage("Payment failed", { orderId: 123, amount: 99.99 });

// Bad
captureMessage(`Payment failed for order 123 with amount 99.99`);

Next Steps

Configuration Guide

Learn about all SDK configuration options

Capturing Errors

Understand error and message capture patterns

Dashboard Features

Explore VIJ Admin dashboard capabilities

API Endpoints

View the HTTP API documentation

​Functions

​init()

​captureException()

​captureMessage()

​flush()

​setMetadata()

​clearMetadata()

​getMetadata()

​Types

​InitOptions

​Severity

​LogEntry

​BrowserContext

​NodeContext

​Advanced Usage

​Manual Queue Management

​Dynamic Metadata Updates

​TypeScript Integration

​React Integration

​Express Integration

​Best Practices

​Next Steps

Configuration Guide

Capturing Errors

Dashboard Features

API Endpoints

Functions

init()

captureException()

captureMessage()

flush()

setMetadata()

clearMetadata()

getMetadata()

Types

InitOptions

Severity

LogEntry

BrowserContext

NodeContext

Advanced Usage

Manual Queue Management

Dynamic Metadata Updates

TypeScript Integration

React Integration

Express Integration

Best Practices

Next Steps