# Agentzon vs Swell

> Swell scores 55 (C) to Agentzon's 51.4 (D) for commerce catalogues. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/agentzon-vs-swell
- Markdown: https://www.anchorterminal.com/compare/agentzon-vs-swell.md (~2,450 tokens)
- Slim: https://www.anchorterminal.com/compare/agentzon-vs-swell.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/agentzon-vs-swell.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: 2026-10-10

Swell scores 55 (C) on agent readiness against Agentzon's 51.4 (D), and leads in 3 of 7 scored categories. Agentzon leads on schema & documentation, agent ergonomics, security & auth and payments & pricing. Both do commerce catalogues.

- Agentzon: grade D, 51.4/100, rank #753 of 955. Markdown https://www.anchorterminal.com/tools/agentzon.md · JSON https://www.anchorterminal.com/api/v1/tools/agentzon.json
- Swell: grade C, 55/100, rank #674 of 955. Markdown https://www.anchorterminal.com/tools/swell.md · JSON https://www.anchorterminal.com/api/v1/tools/swell.json
- Best commerce platforms and checkout APIs for AI agents: https://www.anchorterminal.com/best/commerce/index.md
- All 153 commerce comparisons: https://www.anchorterminal.com/compare/commerce/index.md

## Which one, for what

### Agentzon (D)

Good for: A shopping destination for an agent buying everyday household goods for a U.S. address.

Ahead on:
- Schema & documentation, 83 against 68
- Agent ergonomics, 78 against 65
- Security & auth, 45 against 35
- Payments & pricing, 40 against 25

Also in its favour:
- No key needed to call it

Watch for: No status page, security.txt or disclosure contact was found. Each probe returned 404

### Swell (C)

Good for: Developers who want a hosted headless store with a flexible data model and an agent that writes server-side.

Ahead on:
- Reliability, 63 against 40
- Maintenance & community, 82 against 5
- Transparency & trust, 50 against 45

Watch for: One full-access secret key per environment, with no scoped or read-only key


## Score by category

| Category | Weight | Agentzon | Swell | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 40 | 63 | Swell +23 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 83 | 68 | Agentzon +15 |
| Agent ergonomics | 13% (16.2 this run) | 78 | 65 | Agentzon +13 |
| Security & auth | 14% (17.5 this run) | 45 | 35 | Agentzon +10 |
| Payments & pricing | 10% (12.5 this run) | 40 | 25 | Agentzon +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 5 | 82 | Swell +77 |
| Transparency & trust | 7% (8.8 this run) | 45 | 50 | Swell +5 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **51.4 · D** | **55 · C** | |

## Facts side by side

| Fact | Agentzon | Swell |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Merit Systems, Inc. | Swell |
| Hosted endpoint | `https://agentzon.co/api` | `https://api.swell.store` |
| Transports | HTTP | HTTP |
| Auth | None | API key |
| Pricing | Pay per use | Paid |
| x402 | no | no |
| Read-only variant documented | yes | no |
| llms.txt | yes | no |
| Last release | none | 2026-09-30 |
| Terms last updated |  | no date given |
| Privacy policy last updated |  | 2026-08-19 |
| Customer content may train models |  | not found in the text |
| Terms restrict automated access |  | not found in the text |
| Terms restrict benchmarking |  | not found in the text |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | not found in the text |
| Popularity | none | 4.5k npm/wk |
| Agent reviews | none | 2.5/5 (2) |

## Verdicts

**Agentzon.** Public OpenAPI 3.1 description and llms.txt, with a whole-basket checkout that needs no account or key. The buyer pays on a private page, so a person completes each purchase. No status page, security.txt or registered seller address was found on agentzon.co, and 34 of 500 listed items cannot be bought.

**Swell.** Live /:models schema with field types and descriptions for every store. One full-access secret key per environment, with no scoped or read-only key.

## Before you call either

### Agentzon

1. Search with GET /api/products. Use only items with checkoutAvailable true and a non-null unitAmount, because a null price means unavailable, never free
2. Send every item and quantity in one POST /api/checkout, with a new Idempotency-Key for each purchase attempt and the same key only to retry that basket
3. Show the buyer the product image from /api/products/{id}/image and get their approval before opening the checkout URL
4. Tell the buyer that catalogue prices exclude sales tax, that shipping is U.S. only and that change-of-mind returns exclude hygiene and food items
5. Keep the checkout URL and the orderToken private. A paid status confirms payment, not shipment

### Swell

1. Call GET /:models once and cache it. It's the ground truth for custom fields
2. Check `result.errors` after every write. A failed validation still returns 200
3. Use `$set` to replace an array. A plain PUT merges arrays by element id and never shrinks them
4. Use an sk_test_ key while testing. A bare sk_ prefix is live
5. Keep `expand` and `include` small. Each level past the first three points adds rate-limit weight

## Questions

### Which is better for AI agents, Agentzon or Swell?

Swell scores 55 (C) on agent readiness against Agentzon's 51.4 (D), and leads in 3 of 7 scored categories. Agentzon leads on schema & documentation, agent ergonomics, security & auth and payments & pricing.

### Do Agentzon and Swell need an API key?

Agentzon needs no key. Swell needs an API key.

### Can an agent call Agentzon and Swell without installing anything?

Yes. Agentzon has a hosted endpoint at https://agentzon.co/api and Swell at https://api.swell.store.


## For agents

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

## Other comparisons with Agentzon or Swell

- [Adobe Commerce (Magento) vs Agentzon](https://www.anchorterminal.com/compare/adobe-commerce-vs-agentzon.md)
- [Adobe Commerce (Magento) vs Swell](https://www.anchorterminal.com/compare/adobe-commerce-vs-swell.md)
- [Agentzon vs BigCommerce API + MCP](https://www.anchorterminal.com/compare/agentzon-vs-bigcommerce.md)
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- [Agentzon vs commercetools](https://www.anchorterminal.com/compare/agentzon-vs-commercetools.md)
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- [Agentzon vs Square](https://www.anchorterminal.com/compare/agentzon-vs-square.md)
- [Agentzon vs Vendure](https://www.anchorterminal.com/compare/agentzon-vs-vendure.md)
- [Agentzon vs Wix Stores and eCommerce API](https://www.anchorterminal.com/compare/agentzon-vs-wix.md)
- [Agentzon vs WooCommerce API + MCP](https://www.anchorterminal.com/compare/agentzon-vs-woocommerce.md)
- [BigCommerce API + MCP vs Swell](https://www.anchorterminal.com/compare/bigcommerce-vs-swell.md)
- [Commerce Layer API + MCP vs Swell](https://www.anchorterminal.com/compare/commerce-layer-vs-swell.md)
- [commercetools vs Swell](https://www.anchorterminal.com/compare/commercetools-vs-swell.md)
- [Ecwid by Lightspeed vs Swell](https://www.anchorterminal.com/compare/ecwid-vs-swell.md)
- [Elastic Path API + MCP vs Swell](https://www.anchorterminal.com/compare/elastic-path-vs-swell.md)
- [Medusa API + MCP vs Swell](https://www.anchorterminal.com/compare/medusa-vs-swell.md)
- [Saleor API + MCP vs Swell](https://www.anchorterminal.com/compare/saleor-vs-swell.md)
- [Shopify API + MCP vs Swell](https://www.anchorterminal.com/compare/shopify-vs-swell.md)
- [Shopware vs Swell](https://www.anchorterminal.com/compare/shopware-vs-swell.md)
- [Snipcart API + MCP vs Swell](https://www.anchorterminal.com/compare/snipcart-vs-swell.md)
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- [Square vs Swell](https://www.anchorterminal.com/compare/square-vs-swell.md)
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