References

The references describe every endpoint, event and frame exactly as the servers implement them. They are generated from the code and the published OpenAPI specs, so they change when the API changes. For step-by-step explanations, start with the Guides.

Reference	What it covers	Base URL
REST API	Email, Support (chat), Payments, API keys and webhooks: every endpoint with parameters, request and response schemas, code samples and a "Try it" console	https://api.hatang.dev
Chat gateway API	What the website widget, the mobile SDKs and the agent apps call: bootstrap, conversations, uploads, devices, the agent API	https://chat.hatang.dev
Webhook events	Every event with its payload	your endpoint
Realtime protocol	The visitor websocket: every frame, field and limit	wss://chat.hatang.dev/ws
Errors	Every error code of the API, the realtime protocol and the SMTP relay
Limits	Rate limits and size limits

SDK references

Generated from the doc comments in each SDK's source, one site per SDK (English only):

SDK	Reference
Node (@hatang/sdk)	TypeDoc
Flutter (hatang_chat)	dartdoc
iOS (HatangChat, HatangChatCore)	DocC
Android (dev.hatang:chat, dev.hatang:chat-core)	Dokka

Conventions

• Authentication. REST calls send Authorization: Bearer ht_.... See Authentication for scopes and test keys.
• Format. JSON in and out, UTF-8. Timestamps are ISO 8601 in UTC; amounts in Vietnamese đồng are integers.
• Errors. Every error is { "statusCode", "name", "message" }; branch on name.
• Pagination. List endpoints take limit and after, and answer with has_more and next_cursor. See Pagination.
• Idempotency. POST /emails, POST /payments and posting chat messages accept an Idempotency-Key header. See Idempotency.

Machine-readable specs

• REST API: openapi.json (OpenAPI 3.1, including the webhooks section)

• Chat gateway: openapi.json

• Realtime protocol: JSON Schemas for visitor frames, server frames, HTTP and protocol constants

• The whole hub for AI agents and LLM tools: llms.txt (an index), llms-full.txt (every page in one file), and a Markdown copy of each page at its URL plus .md, such as /docs/reference/overview.md

Use them with any OpenAPI tool (Postman, Insomnia, code generators) or import them into your own tests.