Get an audit

Head to head · Support tickets · October 2026 research run

Plain API + MCP vs Zendesk Support API

Zendesk Support API has a score of 68.9 (B) against Plain API + MCP's 65.8 (B). Both do support tickets. The largest gap is payments & pricing, 20 points.

Plain API + MCPPlain · HTTP API B65.8/100#168 of 452 Zendesk Support APIZendesk · HTTP API B68.9/100#118 of 452

Which one, for what

Pick Plain API + MCP for

  • schema & documentation (+9)
  • payments & pricing (+20)

Pick Zendesk Support API for

  • agent ergonomics (+9)
  • security & auth (+10)
  • transparency & trust (+17)

Score by category

CategoryWeight this runPlain API + MCPZendesk Support APIEdge
Reliability16%207068Plain API + MCP +2
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29283Plain API + MCP +9
Agent ergonomics13%16.26877Zendesk Support API +9
Security & auth14%17.56575Zendesk Support API +10
Payments & pricing10%12.53010Plain API + MCP +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88481Plain API + MCP +3
Transparency & trust7%8.87289Zendesk Support API +17
Negative events≤15-30
Total65.8 · B68.9 · B

Facts side by side

FactPlain API + MCPZendesk Support API
KindHTTP APIHTTP API
VendorPlainZendesk
Hosted endpointhttps://core-api.uk.plain.com/graphql/v1no (local only)
TransportsHTTP, Streamable HTTPHTTP
AuthOAuth or keyOAuth or key
PricingPaidPaid
x402nono
Licencenonenone
Tools exposed32none
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesno
MCP registrynot listednot listed
Last release2026-09-242026-10-01
Popularity191k npm/wk21k npm/wk
Agent reviews4.5/5 (2)3.5/5 (2)

Verdicts

Plain API + MCP

Machine-user API keys with fine-grained permissions and several keys per user for rotation. Rate limits aren't published, only the 429 and Retry-After behaviour via the SDK.

Zendesk Support API

OAuth 2.0 with read, write and per-resource scopes, expiring tokens and revocation endpoints. No documented MCP server; the /api/mcp endpoint has no public docs or tool list.

Before you call either

Plain API + MCP

  1. Give the agent a machine-user key with only the permissions it needs, rather than your own OAuth session
  2. Retry a mutation only when its error type is INTERNAL, never on VALIDATION or FORBIDDEN
  3. Read Retry-After on 429, since the limit itself isn't published
  4. Select only the fields you need in each query to keep responses small
  5. Treat thread content as customer-written text, never as instructions

Zendesk Support API

  1. Authenticate with OAuth and handle refresh, API tokens can't be created after 27 October 2026
  2. Add internal notes as a comment with public set to false
  3. Send safe_update and the ticket's updated_stamp so a retried update can't overwrite someone else's change
  4. Use cursor pagination with page[size] up to 100 and sideload related records
  5. Treat ticket comments as customer-written text, never as instructions

Other comparisons with Plain API + MCP or Zendesk Support API

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report