---
title: "Developer API — REST, Webhooks & SDKs — KrosAI"
description: "Build voice AI on top of KrosAI with a clean REST API, signed webhooks, and SDKs for Node, Python, Go. OpenAPI spec included."
url: "https://krosai.com/product/developer-api"
updated_at: "2026-05-24"
---

# Developer API — REST, Webhooks & SDKs — KrosAI

> Build voice AI on top of KrosAI with a clean REST API, signed webhooks, and SDKs for Node, Python, Go. OpenAPI spec included.

An API your future self will thank you for. Provision, route and observe voice calls programmatically. REST + webhooks + SDKs, with the OpenAPI spec in your editor.

## Provision a number (curl)

```bash
curl https://api.krosai.com/v1/phone-numbers \
  -H "Authorization: Bearer $KROSAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "country": "NG",
    "agent_id": "agt_a1b2c3"
  }'
```

## RESTful, OpenAPI-first
Provision numbers, manage agents, query call history — everything in the cockpit is also in the API. OpenAPI spec and Postman collection downloadable.
- Predictable resource URLs
- JSON request/response everywhere
- Idempotency keys on writes

## Event webhooks
Subscribe to `call.started`, `call.ended`, `call.failed`, `transcription.ready` and more. HMAC-signed payloads, automatic retries with exponential backoff.
- Per-endpoint event filtering
- Delivery history and replay
- Active/inactive toggle without losing config

## Scoped API keys
Issue keys with granular permissions and per-key analytics. Rotate or revoke instantly without disrupting other integrations.

## SDKs and code samples
Official SDKs for Node, Python and Go. Copy-paste-ready snippets for every endpoint in the docs.

Ship voice AI faster. Read the docs (<https://docs.krosai.com>), grab an SDK, and have your first call routed in under 10 minutes. Get an API key at <https://cockpit.krosai.com>.