# Affinity vs Nutshell

> Affinity scores 63.4 (B) on agent readiness against Nutshell's 49.6 (D), and leads in 5 of 7 scored categories. Nutshell leads on payments & pricing. Both do crm records. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/affinity-vs-nutshell
- Markdown: https://www.anchorterminal.com/compare/affinity-vs-nutshell.md (~2,450 tokens)
- Slim: https://www.anchorterminal.com/compare/affinity-vs-nutshell.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/affinity-vs-nutshell.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Affinity scores 63.4 (B) on agent readiness against Nutshell's 49.6 (D), and leads in 5 of 7 scored categories. Nutshell leads on payments & pricing. Both do crm records.

- Affinity: grade B, 63.4/100, rank #311 of 722. Markdown https://www.anchorterminal.com/tools/affinity.md · JSON https://www.anchorterminal.com/api/v1/tools/affinity.json
- Nutshell: grade D, 49.6/100, rank #607 of 722. Markdown https://www.anchorterminal.com/tools/nutshell.md · JSON https://www.anchorterminal.com/api/v1/tools/nutshell.json

## 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 42
- Schema & documentation, 91 against 57
- Agent ergonomics, 66 against 44
- Security & auth, 66 against 58
- Maintenance & community, 70 against 46

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

### 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:
- Payments & pricing, 35 against 10

Also in its favour:
- Free to start without a card

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


## Score by category

| Category | Weight | Affinity | Nutshell | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 64 | 42 | Affinity +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 91 | 57 | Affinity +34 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 44 | Affinity +22 |
| Security & auth | 14% (17.5 this run) | 66 | 58 | Affinity +8 |
| Payments & pricing | 10% (12.5 this run) | 10 | 35 | Nutshell +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 70 | 46 | Affinity +24 |
| Transparency & trust | 7% (8.8 this run) | 70 | 71 | Nutshell +1 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **63.4 · B** | **49.6 · D** | |

## Facts side by side

| Fact | Affinity | Nutshell |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Project Affinity, Inc. | Nutshell, Inc. |
| Hosted endpoint | `https://api.affinity.co/v2` | `https://app.nutshell.com/rest` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under Affinity's master subscription agreement. The `affinity-mcp` package on PyPI is MIT | Proprietary service under Nutshell's Terms of Service |
| Tools exposed | 75 | none |
| Read-only variant documented | yes | yes |
| llms.txt | yes | yes |
| Last release | 2026-10-02 | 2026-08-21 |
| Terms last updated |  | 2026-06-02 |
| Privacy policy last updated | 2026-07-01 | 2026-06-02 |
| Customer content may train models |  | not found in the text |
| Terms restrict automated access |  | not found in the text |
| Terms restrict benchmarking |  | yes |
| Terms or service can change without notice |  | yes |
| Arbitration or class-action waiver |  | yes |
| Popularity | 268 PyPI/wk | none |

## 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.

**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

### 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

### 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, Affinity or Nutshell?

Affinity scores 63.4 (B) on agent readiness against Nutshell's 49.6 (D), and leads in 5 of 7 scored categories. Nutshell leads on payments & pricing.

### Do Affinity and Nutshell need an API key?

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

### Can an agent call Affinity and Nutshell without installing anything?

Yes. Affinity has a hosted endpoint at https://api.affinity.co/v2 and Nutshell at https://app.nutshell.com/rest.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/affinity-vs-nutshell.json, and with the fewest tokens: https://www.anchorterminal.com/compare/affinity-vs-nutshell.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "affinity", "b": "nutshell"}`. From a terminal: `anchor compare affinity nutshell`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/affinity.json and https://www.anchorterminal.com/api/v1/tools/nutshell.json

## Other comparisons with Affinity or Nutshell

- [Affinity vs Attio API + MCP](https://www.anchorterminal.com/compare/affinity-vs-attio.md)
- [Affinity vs Capsule CRM](https://www.anchorterminal.com/compare/affinity-vs-capsule-crm.md)
- [Affinity vs Close API + MCP](https://www.anchorterminal.com/compare/affinity-vs-close.md)
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- [Affinity vs Microsoft Dynamics 365 Sales](https://www.anchorterminal.com/compare/affinity-vs-dynamics-365-sales.md)
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- [Affinity vs Freshsales API](https://www.anchorterminal.com/compare/affinity-vs-freshsales.md)
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- [Affinity vs Zoho CRM](https://www.anchorterminal.com/compare/affinity-vs-zoho-crm.md)
- [Attio API + MCP vs Nutshell](https://www.anchorterminal.com/compare/attio-vs-nutshell.md)
- [Capsule CRM vs Nutshell](https://www.anchorterminal.com/compare/capsule-crm-vs-nutshell.md)
- [Close API + MCP vs Nutshell](https://www.anchorterminal.com/compare/close-vs-nutshell.md)
- [Copper API vs Nutshell](https://www.anchorterminal.com/compare/copper-vs-nutshell.md)
- [Microsoft Dynamics 365 Sales vs Nutshell](https://www.anchorterminal.com/compare/dynamics-365-sales-vs-nutshell.md)
- [folk API + MCP vs Nutshell](https://www.anchorterminal.com/compare/folk-vs-nutshell.md)
- [Freshsales API vs Nutshell](https://www.anchorterminal.com/compare/freshsales-vs-nutshell.md)
- [HubSpot API + MCP vs Nutshell](https://www.anchorterminal.com/compare/hubspot-mcp-vs-nutshell.md)
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- [Nutshell vs Salesforce API + MCP](https://www.anchorterminal.com/compare/nutshell-vs-salesforce.md)
- [Nutshell vs Streak API + MCP](https://www.anchorterminal.com/compare/nutshell-vs-streak.md)
- [Nutshell vs Twenty API + MCP](https://www.anchorterminal.com/compare/nutshell-vs-twenty.md)
- [Nutshell vs Zoho CRM](https://www.anchorterminal.com/compare/nutshell-vs-zoho-crm.md)