HelpDesk vs Zoho Desk

HelpDesk

The API covers the ticket workflow in 139 operations with a public OpenAPI 3.0.3 description, cursor pagination and about 39 list filters. No rate limit, error format or 429 handling was found in the reviewed documentation, and tokens carry no ticket-level scopes, so a token can do whatever its user's role allows.

Zoho Desk

Public OpenAPI 3.1 files cover 911 operations, OAuth scopes separate read, create, update and delete per module, and replies can be saved as drafts or sent for review before a customer sees them. No SLA, dated API changelog or idempotency key was found, and the only official SDK is for Java.

HelpDesk

1. Send Basic auth with the account ID as username and the personal access token as password, and always set a User-Agent header
2. Create the token from a Viewer or Agent account when the task allows. A token inherits its creator's role, and only Administrators can change settings
3. Reply or add a note through PATCH /v1/tickets/{ticketID} with message.text. Set isPrivate to true for an internal note, because the default sends to the requester
4. Page /v1/tickets with next.value and next.ID from the last item, keep sortBy and order fixed, and pass silo to read archive, spam or trash
5. Budget for metered calls. Text's docs count every request except those answered 500 against the plan's monthly API allowance

Zoho Desk

1. Use the api_domain returned with the token. Each data centre has its own host, such as desk.zoho.com, desk.zoho.eu and desk.zoho.in
2. Send Authorization: Zoho-oauthtoken <token> and refresh hourly. Put refresh parameters in the POST body, not the URL
3. Create replies with POST /api/v1/tickets/{id}/draftReply, then sendDraft or sendForReview. sendReply emails the customer
4. Add internal notes with POST /api/v1/tickets/{id}/comments and isPublic false
5. Page with from and limit (50 at most). Deep offsets cost more credits, from 3 a call under 2,000 records to 100 above 100,000