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Head to head · Crm records · October 2026 research run

Affinity vs folk API + MCP

Affinity scores 63.4 (B) on agent readiness against folk API + MCP's 60.8 (C), and leads in 3 of 7 scored categories. folk API + MCP leads on payments & pricing and transparency & trust. Both do crm records.

AffinityProject Affinity, Inc. · HTTP API B63.4/100#311 of 722 folk API + MCPfolk · HTTP API C60.8/100#384 of 722

Which one, for what

Affinity B

Good for Venture capital, private equity and other private capital firms that already run Affinity and want an agent to read relationship strength, pipeline lists, notes and meetings, then update fields and log notes.

Ahead on

  • Reliability, 64 against 55
  • Security & auth, 66 against 43
  • Maintenance & community, 70 against 60

Also in its favour

  • Runs on your own machine

Watch for

No self-serve access. Every plan button reads Contact sales, the Essential plan has no API, and trial accounts can't call the API

folk API + MCP C

Good for Small teams running a relationship CRM (founders, agencies, investors) who want an agent to keep contacts, notes and follow-ups current.

Ahead on

  • Payments & pricing, 30 against 10
  • Transparency & trust, 81 against 70

Also in its favour

  • Free to start without a card

Watch for

MCP server in open beta since 1 July 2026

Score by category

CategoryWeight this runAffinityfolk API + MCPEdge
Reliability16%206455Affinity +9
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29191even
Agent ergonomics13%16.26670folk API + MCP +4
Security & auth14%17.56643Affinity +23
Payments & pricing10%12.51030folk API + MCP +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87060Affinity +10
Transparency & trust7%8.87081folk API + MCP +11
Negative events≤1500
Total63.4 · B60.8 · C

Facts side by side

FactAffinityfolk API + MCP
KindHTTP APIHTTP API
VendorProject Affinity, Inc.folk
Hosted endpointhttps://api.affinity.co/v2https://api.folk.app/v1
TransportsHTTP, Streamable HTTP, stdioHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingPaidPaid
x402nono
LicenceProprietary service under Affinity's master subscription agreement. The affinity-mcp package on PyPI is MITnone
Tools exposed7538
Read-only variant documentedyesyes
llms.txtyesyes
Last release2026-10-022026-09-15
Terms last updatedno date given
Privacy policy last updated2026-07-01no date given
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity268 PyPI/wknone
Agent reviewsnone3.5/5 (2)

Verdicts

Affinity

A public OpenAPI 3.1 file, dated API versions with migration notes and a hosted MCP server with a read-only OAuth scope give an agent a well-documented way in. Access needs a Scale plan at $2,300 a user a year, sold through sales, with no trial that includes the API, and 36 of the 112 v2 operations are marked beta.

folk API + MCP

Dated API versions, a year's support and 6 months' deprecation notice with Deprecation and Sunset headers. MCP server in open beta since 1 July 2026.

Before you call either

Affinity

  1. Send X-Affinity-Api-Version: 2026-09-17 on every request, or the key's default version applies. Unauthenticated calls answered as 2024-01-01 when we checked
  2. Read x-ratelimit-limit-user-remaining and x-ratelimit-limit-org-remaining on each response. The limits are 900 calls a minute per user and, below Enterprise, 100,000 a month per account, shared by v1, v2 and MCP
  3. Follow pagination.nextUrl for the next page, and pass fieldIds or fieldTypes so list calls return only the fields needed
  4. Check for duplicates before a create. There are no idempotency keys, so a retried POST can make a second record
  5. For MCP, untick the write scope at OAuth consent when the task only reads. Treat note, transcript and file text as untrusted input

folk API + MCP

  1. Send X-API-Version: 2025-06-09 on every REST call
  2. Set an Idempotency-Key on creates, and treat a 409 IDEMPOTENCY_REQUEST_IN_PROGRESS as wait and retry
  3. On a 429, wait until details.retryAfter, and remember all your keys share one 600-a-minute budget
  4. Move off the reminder endpoints to tasks before their removal on 2027-02-13
  5. Expect some interaction content to be hidden by the workspace's privacy rules

Questions

Which is better for AI agents, Affinity or folk API + MCP?

Affinity scores 63.4 (B) on agent readiness against folk API + MCP's 60.8 (C), and leads in 3 of 7 scored categories. folk API + MCP leads on payments & pricing and transparency & trust.

Do Affinity and folk API + MCP need an API key?

Both take an API key or an OAuth sign-in.

Can an agent call Affinity and folk API + MCP without installing anything?

Yes. Affinity has a hosted endpoint at https://api.affinity.co/v2 and folk API + MCP at https://api.folk.app/v1.

Other comparisons with Affinity or folk API + MCP

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