ButterCMS vs Contentstack

ButterCMS

The Read and Write APIs have a public OpenAPI 3.1 file, Markdown docs and a status page with no incident since October 2025. The Write API is a paid add-on from the $249 plan, capped at 2,000 or 5,000 calls a month. Writes answer 202 with no identifier, support rotates tokens, and the terms are an undated website document.

Contentstack

The Content Management API has a public OpenAPI file, OAuth scopes that separate read, write and publish, read-only management tokens and a stack audit log. A free plan needs no card. The MCP server loads 78 tools by default with no annotations or read-only switch, and the limit=0 behaviour changed on 11 September 2026 without advance notice.

ButterCMS

1. End every path with a slash. A missing slash returns a 301, and the vendor counts the redirect and the retry as two API calls
2. Send the write token only as Authorization: Token <token>. The auth_token query parameter works for reads only
3. On page creation send every field key of the page type, with empty strings for fields left blank
4. A 202 means queued, not saved. Read the entry back with preview=1 to confirm, and check a slug exists before retrying a create
5. Call the REST API directly for writes. The JavaScript SDK 3.0.3 has list, retrieve and search methods only

Contentstack

1. Pick the base URL for the stack's region first. North America on AWS is https://api.contentstack.io, and the other six regions use contentstack.com hosts
2. Send api_key and authorization headers on every Content Management API call. Ask for a read-only management token when the task only reads
3. Page with limit (100 at most), skip and include_count=true. limit=0 no longer returns everything
4. Stay under 10 reads and 10 writes a second per organisation, and one bulk request a second. Watch X-RateLimit-Remaining and back off on 429
5. Start the MCP server with --groups cma only, and add cma-extended when the task needs audit logs or version history. Publishing and deleting need no confirmation