API Reference

The thig.ai API provides programmatic access to projects, PRDs, templates, AI tools, exports, and more.

Base URL

https://app.thig.ai/api

Authentication

All API requests require authentication via session cookies or API keys. See Authentication for details.

Response Format

Success Response

{
  "success": true,
  "data": { ... }
}

Some endpoints return the data directly without a wrapper:

{
  "projects": [...],
  "total": 42
}

Error Response

{
  "error": "Error message describing what went wrong",
  "code": "ERROR_CODE"
}

Common HTTP Status Codes

Code	Meaning
`200`	Success
`201`	Created
`400`	Bad Request — invalid input
`401`	Unauthorized — not authenticated
`403`	Forbidden — insufficient permissions or feature disabled
`404`	Not Found
`429`	Rate Limited — too many requests
`500`	Internal Server Error

Rate Limiting

API requests are rate-limited based on:

Subscription tier — Higher plans get higher limits
Endpoint type — AI endpoints have stricter limits than CRUD endpoints

When rate limited, you’ll receive a 429 response. Wait and retry after the indicated period.

Streaming Endpoints

AI-powered endpoints use Server-Sent Events (SSE) for streaming responses. Event types:

Event Type	Description
`progress`	Phase update with percentage (e.g., “Analyzing requirements… 25%“)
`content`	Text content chunk
`done`	Final complete result
`error`	Error with message and optional code

Handling SSE Streams

const response = await fetch('/api/generate-prd/stream', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ projectId: 'xxx' })
});

const reader = response.body.getReader();
const decoder = new TextDecoder();

while (true) {
  const { done, value } = await reader.read();
  if (done) break;

  const text = decoder.decode(value);
  const lines = text.split('\n');

  for (const line of lines) {
    if (line.startsWith('data: ')) {
      const event = JSON.parse(line.slice(6));
      // Handle event based on event.type
    }
  }
}

Feature Flags

Some endpoints are gated by feature flags and may return 403 if the feature is disabled for your organization. Feature-gated endpoints are noted in their documentation.

API Sections

Projects

CRUD operations for PRD projects

Chat & PRD Generation

AI conversation and PRD generation

AI Tools

User stories, tech specs, roadmaps, wireframes

Templates

Template CRUD and marketplace

Exports

PDF, DOCX, HTML, Notion, Google Docs export

Organization

Org settings, members, branding, domain

User

Profile, BYOK keys, onboarding, data export

Webhooks & Integrations

Outgoing webhooks and third-party integrations

Notifications

In-app notifications, preferences, scheduled exports

Usage & Billing

Usage metrics, plan limits, billing management

Admin & Enterprise

Teams, approval workflows, audit logs, IP allowlist

​API Reference

​Base URL

​Authentication

​Response Format

​Success Response

​Error Response

​Common HTTP Status Codes

​Rate Limiting

​Streaming Endpoints

​Handling SSE Streams

​Feature Flags

​API Sections