# Particle Health vs Zus Health

> Zus Health scores 56.6 (C) to Particle Health's 48.6 (D) for patient record retrieval. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/particle-health-vs-zus-health
- Markdown: https://www.anchorterminal.com/compare/particle-health-vs-zus-health.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/particle-health-vs-zus-health.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/particle-health-vs-zus-health.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
- Licence: CC BY 4.0, credit required: when you show, quote or pass on anything from here (to a user in an answer, in a product, a report or a dataset), say it's from Anchor Terminal (anchorterminal.com) and link the page or API address you took it from. Reviews also credit their author.
- Updated: 2026-10-15

Zus Health scores 56.6 (C) on agent readiness against Particle Health's 48.6 (D), and leads in 5 of 7 scored categories. Particle Health leads on security & auth. Both do patient record retrieval.

- Particle Health: grade D, 48.6/100, rank #879 of 1094. Markdown https://www.anchorterminal.com/tools/particle-health.md · JSON https://www.anchorterminal.com/api/v1/tools/particle-health.json
- Zus Health: grade C, 56.6/100, rank #674 of 1094. Markdown https://www.anchorterminal.com/tools/zus-health.md · JSON https://www.anchorterminal.com/api/v1/tools/zus-health.json
- Best health record and wellness data APIs for AI agents: https://www.anchorterminal.com/best/health-data/index.md
- All 63 health comparisons: https://www.anchorterminal.com/compare/health-data/index.md

## Which one, for what

### Particle Health (D)

Good for: US providers, payers and digital health companies that need a patient's network records as FHIR or flat data, and care-event alerts.

Ahead on:
- Security & auth, 57 against 49

Watch for: Credentials come from a Particle representative, and the 'play for free' sign-up domain did not resolve

### Zus Health (C)

Good for: US care organisations and digital health builders that want a shared, continuously refreshed patient profile in FHIR with EHR embedding.

Ahead on:
- Reliability, 66 against 58
- Schema & documentation, 77 against 69
- Agent ergonomics, 67 against 53
- Maintenance & community, 64 against 27
- Transparency & trust, 59 against 48

Watch for: No public prices, and the sandbox is requested through a Google Form


## Score by category

| Category | Weight | Particle Health | Zus Health | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 58 | 66 | Zus Health +8 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 69 | 77 | Zus Health +8 |
| Agent ergonomics | 13% (16.2 this run) | 53 | 67 | Zus Health +14 |
| Security & auth | 14% (17.5 this run) | 57 | 49 | Particle Health +8 |
| Payments & pricing | 10% (12.5 this run) | 5 | 5 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 27 | 64 | Zus Health +37 |
| Transparency & trust | 7% (8.8 this run) | 48 | 59 | Zus Health +11 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **48.6 · D** | **56.6 · C** | |

## Facts side by side

| Fact | Particle Health | Zus Health |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Particle Health, Inc. | Zus Health, Inc. |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP | HTTP |
| Auth | OAuth | OAuth |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under customer agreements. The public terms of use (effective 15 October 2020) cover the website only | Proprietary service under the Zus Builder Terms of Service (last updated 11 March 2025), the Developer Sandbox Terms and the Zus Business Associate Addendum |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | none | 2026-10-14 |
| Terms last updated | 2020-10-15 | 2025-03-11 |
| Privacy policy last updated | 2026-07-29 | 2026-06-24 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |

## Verdicts

**Particle Health.** Particle queries Carequality, CommonWell, eHealth Exchange and state HIEs for a patient and returns FHIR R4B, flat data or C-CDA, with project-scoped 60-minute tokens and OpenAPI fragments per endpoint. Credentials come through a representative, the free sign-up link was dead on 14 October 2026, and rate limits, SLA and changelog are unpublished.

**Zus Health.** FHIR R4 over an aggregated patient profile drawn from CommonWell, Carequality, Surescripts, Quest and ADT networks, with published rate limits, a 99.5 per cent SLA and a dated changelog. Accounts and sandboxes are provisioned by Zus on request, with no public prices, no named security certification and no SDK.

## Before you call either

### Particle Health

1. Pass `projects/<project_id>` as the scope when requesting a token, and request a new one every 60 minutes
2. Poll Get Query Status, or wait for the query-complete webhook, before reading FHIR or flat data
3. Back off on 429, since limits change with system load
4. Pass continuation tokens back verbatim when paging
5. Use the published synthetic patients in sandbox, and stay under 500 queries a day

### Zus Health

1. Cache the access token for its hour. More than 200 token requests an hour per App Client returns 429
2. Request Patient History at most once per patient per 24 hours, and poll the job status endpoint
3. Use conditional create by identifier so a retried write doesn't duplicate a resource
4. Send `Zus-If-Match` with the resource's ETag on PUT and PATCH
5. Set `_count` up to 500 on searches, since the default page is 10

## Questions

### Which is better for AI agents, Particle Health or Zus Health?

Zus Health scores 56.6 (C) on agent readiness against Particle Health's 48.6 (D), and leads in 5 of 7 scored categories. Particle Health leads on security & auth.

### Do Particle Health and Zus Health need an API key?

Both use an OAuth sign-in.

### Can an agent call Particle Health and Zus Health without installing anything?

No hosted endpoint is listed for Particle Health. No hosted endpoint is listed for Zus Health.


## For agents

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

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