fhir-developer-skill-hardened

fhir-developer-skill-hardened is a skill for Claude Code from faberlens/hardened-skills. It costs 135 tokens per session (2,599 once invoked), scanned A, a copy of fhir-developer-skill, MIT.

A development guide for building healthcare APIs that use FHIR, a standard format for exchanging medical records between software systems. It covers common resources, validation, HTTP responses, and SMART on FHIR authorization.

In plain words
What is it for?
Use it to create FHIR REST endpoints for records such as patients, observations, encounters, conditions, and medication requests.
Why use it?
It helps avoid incorrect medical-resource formats, status codes, validation rules, and authorization behavior when building healthcare endpoints.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python scripts/setup_fhir_project.py my_fhir_api.

Part of the health-hardened-skills plugin — 10 skills shipped together

Good fit Use it to create FHIR REST endpoints for records such as patients, observations, encounters, conditions, and medication requests.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/faberlens/hardened-skills
agentmods
npx agentmods add skills/faberlens/hardened-skills/fhir-developer-hardened

Made for: Claude Code.

Or install health-hardened-skills, the plugin that ships this one along with the rest of its 10 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fhir-developer-skill-hardened

README.md
[![agentmods](https://agentmods.dev/badge/skills/faberlens/hardened-skills/fhir-developer-hardened/github.svg)](https://agentmods.dev/skills/faberlens/hardened-skills/fhir-developer-hardened)
Your own site
<a href="https://agentmods.dev/skills/faberlens/hardened-skills/fhir-developer-hardened"><img src="https://agentmods.dev/badge/skills/faberlens/hardened-skills/fhir-developer-hardened/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for fhir-developer-skill-hardened

Your own site · 80×15
<a href="https://agentmods.dev/skills/faberlens/hardened-skills/fhir-developer-hardened"><img src="https://agentmods.dev/badge/skills/faberlens/hardened-skills/fhir-developer-hardened.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 135 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,599 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 97% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00135 $0.02599
Opus 5 $0.00068 $0.01300
Sonnet 5 $0.00027 $0.00520
Haiku 4.5 $0.00014 $0.00260

Measured 8d ago against content hash beeff867ce91, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

fhir-developer-skill-hardened scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

97% identical to fhir-developer-skill — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/fhir-developer-hardened/SKILL.md · 302 lines

How it starts

The opening of the file, as written. The whole thing — 302 lines — stays where its author put it; the contents beside it link to each section on GitHub.

FHIR Developer Skill

Quick Reference

HTTP Status Codes

Code When to Use
200 OK Successful read, update, or search
201 Created Successful create (include Location header)
204 No Content Successful delete
400 Bad Request Malformed JSON, wrong resourceType
401 Unauthorized Missing, expired, revoked, or malformed token (RFC 6750)
403 Forbidden Valid token but insufficient scopes
404 Not Found Resource doesn't exist
412 Precondition Failed If-Match ETag mismatch (NOT 400!)
422 Unprocessable Entity Missing required fields, invalid enum values, business rule violations

Required Fields by Resource (FHIR R4)

Resource Required Fields Everything Else
Patient (none) All optional
Observation status, code Optional
Encounter status, class Optional (including subject, period)
Condition subject Optional (including code, clinicalStatus)
MedicationRequest status, intent, medication[x], subject Optional
Medication (none) All optional
Bundle type Optional

Required vs Optional Fields (CRITICAL)

Only validate fields with cardinality starting with "1" as required.

Cardinality Required?
0..1, 0..* NO
1..1, 1..* YES

Common mistake: Making subject or period required on Encounter. They are 0..1 (optional).


Value Sets (Enum Values)

Invalid enum values must return 422 Unprocessable Entity.

Patient.gender

male | female | other | unknown

Observation.status

registered | preliminary | final | amended | corrected | cancelled | entered-in-error | unknown

Encounter.status

planned | arrived | triaged | in-progress | onleave | finished | cancelled | entered-in-error | unknown

Encounter.class (Common Codes)

Code Display Use
AMB ambulatory Outpatient visits
IMP inpatient encounter Hospital admissions
EMER emergency Emergency department
VR virtual Telehealth

Read the full file on GitHub · 302 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 302 lines · 135 tokens per session scan A beeff867ce91

Subscribe to this mod's changes

fhir-developer-skill-hardened is a skill published in the GitHub repository faberlens/hardened-skills (23 stars, last pushed 4mo ago), licensed MIT. It adds 135 tokens to every session and 2,599 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. It is 97% identical to fhir-developer-skill, differing in 9 lines, and is treated as a copy.

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