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Head to head · Crm records · October 2026 research run

Capsule CRM vs Nutshell

Capsule CRM scores 55.7 (C) on agent readiness against Nutshell's 49.6 (D), and leads in 3 of 7 scored categories. Nutshell leads on schema & documentation, security & auth, payments & pricing and maintenance & community. Both do crm records.

Capsule CRMZestia Limited · HTTP API C55.7/100#504 of 722 NutshellNutshell, Inc. · HTTP API D49.6/100#607 of 722

Which one, for what

Capsule CRM C

Good for Small teams already on Capsule who want an agent to read and write contacts, opportunities, projects and tasks over REST with a read-only scope available.

Ahead on

  • Reliability, 83 against 42
  • Agent ergonomics, 59 against 44

Watch for

No OpenAPI file, llms.txt or official SDK was found

Nutshell D

Good for Small sales teams already on Nutshell who want an agent to read pipeline data over MCP or write records over REST at a low seat price.

Ahead on

  • Schema & documentation, 57 against 48
  • Security & auth, 58 against 46
  • Payments & pricing, 35 against 30
  • Maintenance & community, 46 against 38

Watch for

No rate limit numbers, 429 handling or Retry-After found for the REST API

Score by category

CategoryWeight this runCapsule CRMNutshellEdge
Reliability16%208342Capsule CRM +41
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.24857Nutshell +9
Agent ergonomics13%16.25944Capsule CRM +15
Security & auth14%17.54658Nutshell +12
Payments & pricing10%12.53035Nutshell +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83846Nutshell +8
Transparency & trust7%8.87571Capsule CRM +4
Negative events≤1500
Total55.7 · C49.6 · D

Facts side by side

FactCapsule CRMNutshell
KindHTTP APIHTTP API
VendorZestia LimitedNutshell, Inc.
Hosted endpointhttps://api.capsulecrm.com/api/v2https://app.nutshell.com/rest
TransportsHTTPHTTP
AuthOAuth or keyOAuth or key
PricingFreemiumPaid
x402nono
LicenceProprietary service under Capsule's Customer TermsProprietary service under Nutshell's Terms of Service
Read-only variant documentedyesyes
llms.txtnoyes
Last release2026-09-252026-08-21
Terms last updatedno date given2026-06-02
Privacy policy last updated2025-08-212026-06-02
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticeyesyes
Arbitration or class-action waivernot found in the textyes

Verdicts

Capsule CRM

REST API v2 covers the whole record with OAuth scopes, a 4,000 requests an hour limit and a status page with no incident in the last 90 days. There is no OpenAPI file, llms.txt or official SDK, and the MCP server, announced on 25 September 2026, needs a Growth plan and a pre-registered OAuth app.

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.

Before you call either

Capsule CRM

  1. Send Authorization: Bearer <token> to https://api.capsulecrm.com/api/v2. Projects use the old name in paths, /kases
  2. Follow the Link header for the next page. perPage goes up to 100 and the default is 50
  3. On 429, wait until the epoch time in X-RateLimit-Reset. The docs suggest one second between calls
  4. Ask for the read scope when the task only reads. A write with a read-only token answers 403 with insufficient_scope
  5. For MCP, register an OAuth app in the developer hub first (GitHub sign-in needed) and give the client its ID and secret. Personal API tokens are refused

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

Questions

Which is better for AI agents, Capsule CRM or Nutshell?

Capsule CRM scores 55.7 (C) on agent readiness against Nutshell's 49.6 (D), and leads in 3 of 7 scored categories. Nutshell leads on schema & documentation, security & auth, payments & pricing and maintenance & community.

Do Capsule CRM and Nutshell need an API key?

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

Can an agent call Capsule CRM and Nutshell without installing anything?

Yes. Capsule CRM has a hosted endpoint at https://api.capsulecrm.com/api/v2 and Nutshell at https://app.nutshell.com/rest.

Other comparisons with Capsule CRM or Nutshell

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