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Head to head · Crm records · October 2026 research run

Affinity vs Streak API + MCP

Affinity scores 63.4 (B) on agent readiness against Streak API + MCP's 46.4 (D), and leads in 5 of 7 scored categories. Streak API + MCP leads on payments & pricing. Both do crm records.

AffinityProject Affinity, Inc. · HTTP API B63.4/100#311 of 722 Streak API + MCPStreak · HTTP API D46.4/100#647 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

  • Schema & documentation, 91 against 35
  • Agent ergonomics, 66 against 28
  • Security & auth, 66 against 52
  • Maintenance & community, 70 against 60
  • Transparency & trust, 70 against 65

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

Streak API + MCP D

Good for Small teams that run deals out of Gmail and want an agent to update pipelines and add tasks without seeing email bodies.

Ahead on

  • Payments & pricing, 20 against 10

Watch for

MCP tool list and count not published

Score by category

CategoryWeight this runAffinityStreak API + MCPEdge
Reliability16%206468Streak API + MCP +4
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29135Affinity +56
Agent ergonomics13%16.26628Affinity +38
Security & auth14%17.56652Affinity +14
Payments & pricing10%12.51020Streak API + MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87060Affinity +10
Transparency & trust7%8.87065Affinity +5
Negative events≤1500
Total63.4 · B46.4 · D

Facts side by side

FactAffinityStreak API + MCP
KindHTTP APIHTTP API
VendorProject Affinity, Inc.Streak
Hosted endpointhttps://api.affinity.co/v2https://api.streak.com/api/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 exposed75none
Read-only variant documentedyesno
llms.txtyesyes
Last release2026-10-022026-09-16
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 waiveryes
Popularity268 PyPI/wknone
Agent reviewsnone2/5 (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.

Streak API + MCP

MCP server is OAuth only and revocable from account settings. MCP tool list and count not published.

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

Streak API + MCP

  1. Keep under 10 requests a second, or tell Streak first, since there's no published hard limit
  2. Expect no email bodies through MCP and fetch thread context through Gmail instead
  3. Send the API key as the Basic auth username with an empty password
  4. Check the plan before relying on webhooks, which start at Pro+
  5. Handle a 410 as an API version that's no longer supported

Questions

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

Affinity scores 63.4 (B) on agent readiness against Streak API + MCP's 46.4 (D), and leads in 5 of 7 scored categories. Streak API + MCP leads on payments & pricing.

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

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

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

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

Other comparisons with Affinity or Streak API + MCP

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