@indi/runtime

Lightweight SDK for monitoring your APIs in production. Auto-learns response schemas and detects violations — missing fields, type mismatches, schema drift, slow responses, and unexpected status codes.

Zero dependencies. Works with any framework.

Install

npm install @indi/runtime

Quick Start

Sign up at indimapper.com to get your API key and team ID, then:

import { indi } from '@indi/runtime';

indi.init({
  apiKey: 'your-api-key',
  teamId: 'your-team-id',
});

indi.watch('/api/users', { learningPeriod: 20 });
indi.watch('/api/orders', { maxResponseTime: 500 });

How It Works

1. Intercepts — Patches fetch and XMLHttpRequest to inspect responses without affecting your app
2. Learns — Observes the first N responses to build a schema baseline (which fields exist, their types, required vs optional)
3. Validates — After learning, every response is checked against the baseline
4. Reports — Violations are logged to the console and sent to your Indi dashboard

API

indi.init(config)

| Option | Type | Description | |--------|------|-------------| | apiKey | string | Your API key from the dashboard | | teamId | string | Your team ID from the dashboard | | sampleRate | number | 0-1, percentage of requests to validate (default 1) | | defaults.maxResponseTime | number | Max response time in ms | | defaults.expectedStatus | number[] | Expected status codes | | defaults.learningPeriod | number | Responses to observe before locking schema (default 20) |

indi.watch(endpoint, options?)

Start monitoring an endpoint. Supports wildcards: indi.watch('/api/*').

| Option | Type | Description | |--------|------|-------------| | method | string | HTTP method to match | | maxResponseTime | number | Max response time in ms | | expectedStatus | number[] | Expected status codes | | learningPeriod | number | Responses before locking schema |

indi.unwatch(endpoint)

Stop monitoring an endpoint.

indi.destroy()

Unpatch fetch/XHR and clean up.

Violation Types

| Type | Description | |------|-------------| | missing_field | A required field is missing from the response | | type_mismatch | A field's type changed (e.g. number became string) | | schema_drift | A new field appeared that wasn't seen during learning | | slow_response | Response time exceeded the threshold | | unexpected_status | Status code not in the expected list |

License

MIT