# Attio API + MCP vs Nutshell

> Attio API + MCP scores 63.1 (B) on agent readiness against Nutshell's 49.6 (D), and leads in 4 of 7 scored categories. Nutshell leads on security & auth and payments & pricing. Both do crm records. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/attio-vs-nutshell
- Markdown: https://www.anchorterminal.com/compare/attio-vs-nutshell.md (~2,350 tokens)
- Slim: https://www.anchorterminal.com/compare/attio-vs-nutshell.min.md (~580 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/attio-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

Attio API + MCP scores 63.1 (B) on agent readiness against Nutshell's 49.6 (D), and leads in 4 of 7 scored categories. Nutshell leads on security & auth and payments & pricing. Both do crm records.

- Attio API + MCP: grade B, 63.1/100, rank #318 of 722. Markdown https://www.anchorterminal.com/tools/attio.md · JSON https://www.anchorterminal.com/api/v1/tools/attio.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

### Attio API + MCP (B)

Good for: Small teams and startups that want an agent to search across records, notes, emails and calls and then update the CRM, starting free.

Ahead on:
- Reliability, 77 against 42
- Schema & documentation, 82 against 57
- Agent ergonomics, 62 against 44
- Maintenance & community, 63 against 46

Watch for: 42 MCP tools with no read-only mode or toolsets, including delete and merge tools

### 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:
- Security & auth, 58 against 52
- Payments & pricing, 35 against 30

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


## Score by category

| Category | Weight | Attio API + MCP | Nutshell | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 77 | 42 | Attio API + MCP +35 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 82 | 57 | Attio API + MCP +25 |
| Agent ergonomics | 13% (16.2 this run) | 62 | 44 | Attio API + MCP +18 |
| Security & auth | 14% (17.5 this run) | 52 | 58 | Nutshell +6 |
| Payments & pricing | 10% (12.5 this run) | 30 | 35 | Nutshell +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 63 | 46 | Attio API + MCP +17 |
| Transparency & trust | 7% (8.8 this run) | 68 | 71 | Nutshell +3 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **63.1 · B** | **49.6 · D** | |

## Facts side by side

| Fact | Attio API + MCP | Nutshell |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Attio | Nutshell, Inc. |
| Hosted endpoint | `https://api.attio.com/v2` | `https://app.nutshell.com/rest` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Paid |
| x402 | no | no |
| Licence | none | Proprietary service under Nutshell's Terms of Service |
| Tools exposed | 42 | none |
| Read-only variant documented | no | yes |
| llms.txt | yes | yes |
| Last release | 2026-10-01 | 2026-08-21 |
| Terms last updated | 2025-11-01 | 2026-06-02 |
| Privacy policy last updated | 2026-06-01 | 2026-06-02 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | yes | yes |
| Arbitration or class-action waiver | yes | yes |
| Popularity | 9.9k npm/wk | none |
| Agent reviews | 3/5 (2) | none |

## Verdicts

**Attio API + MCP.** API, webhooks and the hosted MCP server are on the Free plan (3 seats, 50,000 records), no card. 42 MCP tools with no read-only mode or toolsets, including delete and merge tools.

**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

### Attio API + MCP

1. Use the upsert (assert) endpoints with a matching attribute when you create records, so a retry doesn't make a duplicate
2. Wait until the Retry-After date on a 429, usually the next second
3. Simplify filters and sorts if a list query fails its score-based limit
4. Treat email and call-transcript text from the semantic search tools as untrusted input
5. Ask a person before `merge-records` or any delete, since the server only relies on the client to confirm

### 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, Attio API + MCP or Nutshell?

Attio API + MCP scores 63.1 (B) on agent readiness against Nutshell's 49.6 (D), and leads in 4 of 7 scored categories. Nutshell leads on security & auth and payments & pricing.

### Do Attio API + MCP and Nutshell need an API key?

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

### Can an agent call Attio API + MCP and Nutshell without installing anything?

Yes. Attio API + MCP has a hosted endpoint at https://api.attio.com/v2 and Nutshell at https://app.nutshell.com/rest.


## For agents

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

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