# Spree Commerce vs Square

> Spree Commerce scores 70.4 (BB) to Square's 69.2 (B) for commerce catalogues. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/spree-commerce-vs-square
- Markdown: https://www.anchorterminal.com/compare/spree-commerce-vs-square.md (~2,750 tokens)
- Slim: https://www.anchorterminal.com/compare/spree-commerce-vs-square.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/spree-commerce-vs-square.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: 2026-10-09

Spree Commerce scores 70.4 (BB) on agent readiness against Square's 69.2 (B), and leads in 3 of 7 scored categories. Square leads on transparency & trust. Both do commerce catalogues.

- Spree Commerce: grade BB, 70.4/100, rank #155 of 950. Markdown https://www.anchorterminal.com/tools/spree-commerce.md · JSON https://www.anchorterminal.com/api/v1/tools/spree-commerce.json
- Square: grade B, 69.2/100, rank #195 of 950. Markdown https://www.anchorterminal.com/tools/square.md · JSON https://www.anchorterminal.com/api/v1/tools/square.json
- Best commerce platforms and checkout APIs for AI agents: https://www.anchorterminal.com/best/commerce/index.md
- All 136 commerce comparisons: https://www.anchorterminal.com/compare/commerce/index.md

## Which one, for what

### Spree Commerce (BB)

Good for: Teams that want to own a Rails commerce backend with marketplace, B2B and multi-region functions and drive it through REST.

Ahead on:
- Reliability, 82 against 58
- Agent ergonomics, 90 against 83
- Payments & pricing, 55 against 40

Also in its favour:
- Agent-ready, a grade of BB or better
- Open source

Watch for: Six GitHub security advisories between 8 January and 20 July 2026, four rated High, most of them access-control flaws on guest carts, orders and addresses

### Square (B)

Good for: Agents working for a seller already on Square, on catalogue, inventory, orders, payment links and customers, online and in person.

Ahead on:
- Transparency & trust, 70 against 60

Also in its favour:
- A hosted endpoint, with nothing to install
- Runs on your own machine
- No incidents deducted, where Spree Commerce loses 5 points for them

Watch for: The MCP server is marked beta, and the remote server reaches production data only


## Score by category

| Category | Weight | Spree Commerce | Square | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 82 | 58 | Spree Commerce +24 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 85 | 87 | Square +2 |
| Agent ergonomics | 13% (16.2 this run) | 90 | 83 | Spree Commerce +7 |
| Security & auth | 14% (17.5 this run) | 65 | 67 | Square +2 |
| Payments & pricing | 10% (12.5 this run) | 55 | 40 | Spree Commerce +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 81 | 81 | even |
| Transparency & trust | 7% (8.8 this run) | 60 | 70 | Square +10 |
| Negative events | ≤15 | -5 | 0 | |
| **Total** | | **70.4 · BB** | **69.2 · B** | |

## Facts side by side

| Fact | Spree Commerce | Square |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Vendo Connect Inc | Block, Inc. |
| Hosted endpoint | no (local only) | `https://mcp.squareup.com/mcp` |
| Transports | HTTP | HTTP, Streamable HTTP, stdio |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Pay per use |
| x402 | no | no |
| Licence | BSD-3-Clause for the backend, MIT for the npm packages. Enterprise Edition code is under a separate commercial licence | Proprietary service under the Square Developer Terms of Service. The MCP server and the OpenAPI specification on GitHub are Apache 2.0, and the Node.js SDK is MIT |
| Tools exposed | none | 3 |
| Read-only variant documented | yes | no |
| llms.txt | yes | yes |
| Last release | 2026-07-28 | 2026-09-16 |
| Terms last updated | no document linked | 2026-09-10 |
| Privacy policy last updated | no document linked | 2026-09-15 |
| Customer content may train models |  | not found in the text |
| Terms restrict automated access |  | yes |
| Terms restrict benchmarking |  | yes |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | yes |
| Popularity | 16k stars, 1.6k npm/wk | 454k npm/wk, 72k PyPI/wk |

## Verdicts

**Spree Commerce.** A self-hosted BSD 3-Clause platform with public OpenAPI files for the Store and Admin APIs, scoped secret keys, documented rate limits and idempotency keys on cart and checkout calls. GitHub lists six security advisories between January and July 2026, four rated High, and the default docs describe the 6.0 release candidate while 5.6.1 is the stable release.

**Square.** The REST API has a public OpenAPI 3.0 spec, OAuth scopes split by read and write for each resource, idempotency keys on writes and a free sandbox. The MCP server is in beta and its remote instance reaches production only. No numeric REST rate limits or SLA were found, and the status page recorded widespread errors on 27 September 2026.

## Before you call either

### Spree Commerce

1. Send a publishable key in `X-Spree-Api-Key` on every Store API call. Add `X-Spree-Token` with the cart token for guest carts, or a customer JWT as a Bearer token
2. Send `Idempotency-Key` with the cart token or a customer JWT on cart, payment and completion calls. A request carrying only the publishable key is never cached
3. Ask for `fields` and `expand` explicitly. Relations are left out by default and `limit` stops at 100
4. Use a secret key with the narrowest scopes for the Admin API. `read_all` gives a read-only key, and the CLI's auto-minted local key is read-only
5. Read the docs under `/docs/v5` for a 5.6 store. The default docs describe 6.0, which renames shipments to fulfilments and splits carts from orders

### Square

1. Test against the sandbox first with the local MCP server and `SANDBOX=true`. The remote server at mcp.squareup.com reaches production only
2. Set `DISALLOW_WRITES=true` on the local MCP server when the task only reads
3. Call `get_service_info`, then `get_type_info`, before each `make_api_request`. The request body is otherwise untyped
4. Send a fresh `idempotency_key` on every write, and reuse it when retrying the same write
5. Pin `Square-Version` in each request. Use a page cursor within 5 minutes of receiving it

## Questions

### Which is better for AI agents, Spree Commerce or Square?

Spree Commerce scores 70.4 (BB) on agent readiness against Square's 69.2 (B), and leads in 3 of 7 scored categories. Square leads on transparency & trust.

### Do Spree Commerce and Square need an API key?

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

### Can an agent call Spree Commerce and Square without installing anything?

No hosted endpoint is listed for Spree Commerce. Square has a hosted endpoint at https://mcp.squareup.com/mcp.

### Are Spree Commerce and Square open source?

Spree Commerce is open source (BSD-3-Clause for the backend, MIT for the npm packages. Enterprise Edition code is under a separate commercial licence). No open-source release is listed for Square.


## For agents

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

## Other comparisons with Spree Commerce or Square

- [Adobe Commerce (Magento) vs Spree Commerce](https://www.anchorterminal.com/compare/adobe-commerce-vs-spree-commerce.md)
- [Adobe Commerce (Magento) vs Square](https://www.anchorterminal.com/compare/adobe-commerce-vs-square.md)
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- [Spree Commerce vs Swell](https://www.anchorterminal.com/compare/spree-commerce-vs-swell.md)
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- [Spree Commerce vs WooCommerce API + MCP](https://www.anchorterminal.com/compare/spree-commerce-vs-woocommerce.md)
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- [Square vs Vendure](https://www.anchorterminal.com/compare/square-vs-vendure.md)
- [Square vs Wix Stores and eCommerce API](https://www.anchorterminal.com/compare/square-vs-wix.md)
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