Nutshell vs Zoho CRM

Nutshell

The REST reference is served as Markdown with an OpenAPI fragment per operation, and the hosted MCP server uses OAuth with PKCE and can only read. No rate limit numbers, error format or API changelog were found in the reviewed documentation, and API keys carry no scopes.

Zoho CRM

A public OpenAPI 3.1 description of 644 operations and OAuth scopes down to one module and one operation suit agent use, and the Free edition includes 5,000 API credits a day. The documented token refresh puts the client secret in the URL, and no SLA, deprecation policy or dated API changelog was found.

Nutshell

1. Authenticate REST calls with HTTP Basic, a Nutshell user's email as username and the API key as password, against https://app.nutshell.com/rest
2. Use IDs in the <number>-<type> form, such as 3-accounts, and send updates as JSON Patch with content-type: application/json-patch+json
3. Page lists with page[limit] and page[page], which is 0-based, and call /accounts/list/fields or the lead and contact equivalents for valid filter keys
4. Use the REST API for writes. The MCP server only reads, and OAuth tokens need the read scope
5. Filter webhook events yourself, because every webhook receives all events and subscriptions are created in Setup, not through the API

Zoho CRM

1. Use the api_domain returned with the token, since each data centre has its own host (zohoapis.com, zohoapis.eu, zohoapis.in and others)
2. Send Authorization: Zoho-oauthtoken <token> and refresh hourly. Put refresh parameters in the POST body, not the URL
3. Pass fields on every list call. Page with page up to 2,000 records, then page_token up to 100,000
4. Create through /{module}/upsert so a retry updates instead of duplicating
5. Budget credits. Convert Lead costs 5, Send Mail 20, a bulk read 50, and calls through the MCP servers draw on the same allowance