Head to head · Patient record retrieval · October 2026 research run

Particle Health vs 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. Both do patient record retrieval.

Best health record and wellness data APIs for AI agents · All 63 health comparisons

Which one, for what

Particle Health D

Best 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

Best 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

CategoryWeight this runParticle HealthZus HealthEdge
Reliability16%205866Zus Health +8
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26977Zus Health +8
Agent ergonomics13%16.25367Zus Health +14
Security & auth14%17.55749Particle Health +8
Payments & pricing10%12.555even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.82764Zus Health +37
Transparency & trust7%8.84859Zus Health +11
Negative events≤1500
TotalD 48.6/100C 56.6/100

Facts side by side

FactParticle HealthZus Health
KindHTTP APIHTTP API
VendorParticle Health, Inc.Zus Health, Inc.
Hosted endpointno (local only)no (local only)
TransportsHTTPHTTP
AuthOAuthOAuth
PricingPaidPaid
x402nono
LicenceProprietary service under customer agreements. The public terms of use (effective 15 October 2020) cover the website onlyProprietary 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 documentednono
llms.txtyesyes
Last releasenone2026-10-14
Terms last updated2020-10-152025-03-11
Privacy policy last updated2026-07-292026-06-24
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticeyesnot found in the text
Arbitration or class-action waiveryesnot 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.

Other comparisons with Particle Health or Zus Health

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.