Cynco OpenAPI Specification

The official OpenAPI specification for the Cynco REST API. This is the single source of truth from which SDKs, documentation, and Postman collections are generated.

---

Quick Links

Resource	URL
Interactive API docs	app.cynco.io/docs/api
Dashboard & API keys	app.cynco.io/settings/api
Status page	status.cynco.io

---

What's in this spec

The Cynco API covers the full lifecycle of business financial data:

• Invoices -- list, get, update, batch create
• Customers -- full CRUD + batch create
• Vendors -- full CRUD + batch create
• Bills -- list, get, update
• Items -- list, get, update, delete
• Accounts -- chart of accounts (read-only)
• Journal Entries -- list, get, create, batch create
• Bank Accounts -- list, get (read-only)
• Bank Transactions -- list (read-only)
• Reports -- trial balance, balance sheet, profit & loss

All endpoints use Bearer token authentication with cak_-prefixed API keys, support field selection, and follow a consistent response envelope.

---

Using the spec

Validate

npm install
npx @redocly/cli lint openapi.yaml

Generate an SDK

Use any OpenAPI-compatible generator. For example, with openapi-generator-cli:

npx @openapitools/openapi-generator-cli generate \
  -i openapi.yaml \
  -g typescript-fetch \
  -o ./sdk-typescript

Import to Postman

1. Open Postman
2. Click Import
3. Select openapi.yaml from this repository
4. All endpoints, parameters, and examples will be imported automatically

Preview documentation locally

npx @redocly/cli preview-docs openapi.yaml

This starts a local server at http://localhost:8080 with interactive API documentation.

---

Repository structure

openapi/
  openapi.yaml          -- The OpenAPI 3.1 specification
  package.json          -- Validation tooling (Redocly)
  .github/
    workflows/
      validate.yml      -- CI: validates the spec on every PR
  LICENSE               -- MIT
  CHANGELOG.md          -- Version history

---

Versioning

This spec follows the Cynco API version. The current API version is v1. Breaking changes result in a new API version; additive changes (new fields, new endpoints) are released within the current version and documented in CHANGELOG.md.

---

Changelog

See CHANGELOG.md for the full version history.

---

Contributing

1. Create a branch from main
2. Edit openapi.yaml
3. Run npx @redocly/cli lint openapi.yaml to validate
4. Open a pull request -- CI will validate the spec automatically
5. Get a review and merge

When adding a new endpoint:

• Add the path under the appropriate tag
• Add or reuse component schemas
• Include at least one example response
• Update CHANGELOG.md

---

License

MIT -- see LICENSE for details.

Copyright 2026 Cynco Sdn Bhd.