# EasyPost vs ShipStation API

> ShipStation API scores 59.3 (C) on agent readiness against EasyPost's 54.3 (C), and leads in 4 of 7 scored categories. EasyPost leads on security & auth, maintenance & community and transparency & trust. Both do shipping rates. Category scores, facts, verdicts and agent notes…

- Canonical: https://www.anchorterminal.com/compare/easypost-vs-shipstation
- Markdown: https://www.anchorterminal.com/compare/easypost-vs-shipstation.md (~2,050 tokens)
- Slim: https://www.anchorterminal.com/compare/easypost-vs-shipstation.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/easypost-vs-shipstation.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

ShipStation API scores 59.3 (C) on agent readiness against EasyPost's 54.3 (C), and leads in 4 of 7 scored categories. EasyPost leads on security & auth, maintenance & community and transparency & trust. Both do shipping rates.

- EasyPost: grade C, 54.3/100, rank #468 of 629. Markdown https://www.anchorterminal.com/tools/easypost.md · JSON https://www.anchorterminal.com/api/v1/tools/easypost.json
- ShipStation API: grade C, 59.3/100, rank #382 of 629. Markdown https://www.anchorterminal.com/tools/shipstation.md · JSON https://www.anchorterminal.com/api/v1/tools/shipstation.json

## Which one, for what

### EasyPost (C)

Good for: An agent that quotes rates across carriers, buys a label, verifies an address, follows tracking by webhook and requests a refund from one merchant account, mainly on US carriers.

Ahead on:
- Security & auth, 47 against 32
- Maintenance & community, 85 against 73
- Transparency & trust, 70 against 64

Watch for: No OpenAPI spec was found in the docs or in the EasyPost GitHub organisation. The reference is prose and tables, with a Postman workspace

### ShipStation API (C)

Good for: An agent working inside a merchant's existing ShipStation account (orders, batches, inventory, labels), or a developer who wants a free sandbox through the ShipStation API plans.

Ahead on:
- Reliability, 64 against 53
- Schema & documentation, 83 against 55
- Payments & pricing, 40 against 22

Watch for: One API key with full account access. No scopes, read-only keys or approval step before a label is bought


## Score by category

| Category | Weight | EasyPost | ShipStation API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 53 | 64 | ShipStation API +11 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 55 | 83 | ShipStation API +28 |
| Agent ergonomics | 13% (16.2 this run) | 63 | 64 | ShipStation API +1 |
| Security & auth | 14% (17.5 this run) | 47 | 32 | EasyPost +15 |
| Payments & pricing | 10% (12.5 this run) | 22 | 40 | ShipStation API +18 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 85 | 73 | EasyPost +12 |
| Transparency & trust | 7% (8.8 this run) | 70 | 64 | EasyPost +6 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **54.3 · C** | **59.3 · C** | |

## Facts side by side

| Fact | EasyPost | ShipStation API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Simpler Postage, Inc. (d/b/a EasyPost) | Auctane LLC d/b/a ShipStation |
| Hosted endpoint | `https://api.easypost.com/v2` | `https://api.shipstation.com/v2` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Proprietary service under the EasyPost Master Customer Agreement. The official client libraries on GitHub are MIT, with the Go library under ISC | Proprietary service under ShipStation's terms of service. The v2 OpenAPI file is marked MIT and the SDKs on GitHub are Apache 2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-28 | 2026-10-01 |
| Terms last updated | 2026-08-25 | no date given |
| Privacy policy last updated | 2026-08-25 | 2026-03-18 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | yes | yes |
| Popularity | 149 stars, 100k npm/wk, 42k PyPI/wk | 6.8k npm/wk |

## Verdicts

**EasyPost.** Docs written for agents (llms.txt, a Markdown copy of each page, a JSON page index), seven official SDKs and free test keys make the REST API easy to start on. No OpenAPI spec or idempotency keys were found, every key has full account access, and the status page shows a connectivity outage on 23 July 2026 that affected all operations.

**ShipStation API.** A public OpenAPI 3.1 contract with 173 operations, Markdown docs for agents and a free ShipStation API plan with a sandbox make a first rate quote or test label reachable without a contract. One API key carries full account access, with no scopes, read-only mode or idempotency keys on label purchases.

## Before you call either

### EasyPost

1. Use a test API key while building. It buys no postage and contacts no carrier, and test tracking codes simulate each tracking status
2. Don't blind-retry `POST /shipments/:id/buy` after a timeout. Retrieve the shipment first and check for `postage_label`, since no idempotency key exists
3. Send the API key as the HTTP Basic username with an empty password on the REST API, and as a Bearer token on the MCP server
4. Handle `errors` as either an array of objects or an array of strings. The docs say both shapes occur
5. Pass a scoped `carrier_accounts` list when rating. Only the first 60 accounts are rated and the call doesn't fail when more are enabled

### ShipStation API

1. Send the key in an `API-Key` header to https://api.shipstation.com/v2. A key that starts `TEST_` runs in the sandbox on the same host
2. Call GET /v2/carriers first. Rate and label calls need `carrier_ids` or a `carrier_id` and a `service_code` from that account
3. Don't blindly retry POST /v2/labels after a timeout. List labels first, then void a duplicate with PUT /v2/labels/{label_id}/void
4. Check the `errors` array on 2XX responses too, and read `error_source` to tell a carrier fault from a ShipStation one
5. On a platform (Standard or Premium) key every label is real and charged. Ask the owner before buying, and void test labels at once

## Questions

### Which is better for AI agents, EasyPost or ShipStation API?

ShipStation API scores 59.3 (C) on agent readiness against EasyPost's 54.3 (C), and leads in 4 of 7 scored categories. EasyPost leads on security & auth, maintenance & community and transparency & trust.

### Do EasyPost and ShipStation API need an API key?

Both need an API key.

### Can an agent call EasyPost and ShipStation API without installing anything?

Yes. EasyPost has a hosted endpoint at https://api.easypost.com/v2 and ShipStation API at https://api.shipstation.com/v2.


## For agents

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

## Other comparisons with EasyPost or ShipStation API

- [EasyPost vs Easyship](https://www.anchorterminal.com/compare/easypost-vs-easyship.md)
- [EasyPost vs Sendcloud](https://www.anchorterminal.com/compare/easypost-vs-sendcloud.md)
- [EasyPost vs Shippo](https://www.anchorterminal.com/compare/easypost-vs-shippo.md)
- [Easyship vs ShipStation API](https://www.anchorterminal.com/compare/easyship-vs-shipstation.md)
- [Sendcloud vs ShipStation API](https://www.anchorterminal.com/compare/sendcloud-vs-shipstation.md)
- [Shippo vs ShipStation API](https://www.anchorterminal.com/compare/shippo-vs-shipstation.md)