On the bundled sample: 9 findings (6 errors, 3 warnings) in 1 file from 10 rules, including a us-core-patient|3.1.1 pin.

Who it’s for
FHIR developers at EHR and health IT vendors moving resources, Bundles and test fixtures to US Core 6.1.0.

What breaks, and when
Certified health IT has had to carry USCDI v3 since 2026-01-01. A profile pinned to US Core 3.1.1 or 5.0.1 claims the USCDI v1 or v2 element set, and a Patient without us-core-genderIdentity misses an element USCDI v3 added.

What you get
• SKILL.md, an offline Node scanner and the 10-rule table
• file:line and the version or extension needed

See it first
The real output of the bundled example is on getreadystack.com/skills/fhir-us-core-profile-check/ — free, no sign-up, so you see what it finds before you pay.

Install in 30 seconds
Unzip into ~/.claude/skills/, then ask Claude Code: “Check the FHIR JSON in this repo for anything that would not meet USCDI v3. Don’t edit anything yet.”. Needs Node 16+.

What it does not do
Not a FHIR validator: no StructureDefinition, cardinality or value-set checks, no server calls, no edits without your OK.

FAQ
Q: How is this different from asking Claude without the skill?
A: The skill carries a dated rule table and a scanner that reads every file, so Claude quotes the exact date and line instead of guessing from memory.
Q: How do I get the files?
A: In your Whop library after paying: the lesson “fhir-us-core-profile-check.zip”.