Open Quality
An open corpus of healthcare quality measures, and a shared record of what implementers have learned about each one. Founder-stewarded today, with a written commitment to community governance as it grows; see GOVERNANCE and VISION.
Publish a measure in CQL, SQL, or SQL-on-FHIR. Everything is validated, versioned, and open for review. Alongside the measures sits the part that usually gets lost: a typed record of interpretation questions, defects, and test cases, attached to the measure and pinned to a version.
Site: https://openquality.us
Why this exists
Quality measurement is rebuilt from scratch inside every organization that does it. Payers, health systems, and vendors each staff teams to implement the same national measures against their own data, then pay auditors to certify the result. The same ambiguities in the same specifications get rediscovered independently, the code is rarely shared, and what one team learns about a measure rarely reaches the next.
There is no common unit for exchanging measure logic, and no shared place to record what the community has figured out. Open Quality is an attempt at both: a package format anyone can publish, and a knowledge corpus anyone can read.
The goal is an open marketplace for measure logic. Somewhere to find a measure, see what other implementers already learned about it, and take the artifacts, without a vendor contract, a licensing negotiation, or knowing the right person to ask. Today a researcher or a small team has none of those things, and pays for access or goes without.
Browsing and downloading work now, through the library, a machine-readable catalogue, and git. Publishing still goes through a pull request. See Status.
Who this is for
Today, getting an answer about a measure depends on knowing the right person.
A recent example. A PhD candidate wrote a Hospital at Home eligibility library that ran at 30 to 40 seconds per patient. He could not tell whether the cause was his logic, his engine, or his data. Someone made an introduction to an engineer who had spent years optimizing CQL. That engineer explained it in one email: defines cache, functions do not, every retrieve iterates the whole bundle. The library now runs in under a second, and returns the same results.
That answer existed because of one introduction. It is not searchable, it is not attached to a measure, and the next person will not find it.
Most people doing this work are not on Zulip, do not attend connectathons, hold no NCQA support contract, and do not work at an insurer with a staff of analysts. As quality measurement moves from manual abstraction to digital, they need somewhere to go that does not depend on who they happen to know.
This is early and honest about it. The package format and the validation core work; the hosted registry does not exist yet. See Status.
How this fits the ecosystem
Open Quality is not another measure engine and not a competitor to the tools people already rely on. It is the open corpus and community layer that sits alongside them.
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cqframework builds the CQL language, the translator, the execution engines, and the annual eCQM/dQM content. Open Quality reuses that tooling and shared libraries rather than reinventing them, and points its content at the same connectathons.
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HL7 CRMI (Canonical Resource Management Infrastructure) defines how knowledge artifacts are packaged, versioned, and moved through a lifecycle. That is the interoperability target, and Open Quality tracks it rather than inventing a parallel model.
oq fhir-bundleemits the package as a CRMI artifact Bundle, the shape CRMI's$packageoperation returns, written as a file because there is no server here to run an operation on.oq fhir-packageemits a FHIR NPM package that CQL Studio, the FHIR package registry, and IG Publisher already read. Both are built from one list of resources, so the two forms cannot drift apart.What still does not exist is a repository service: no
$package, no$data-requirements, no search API. The artifacts are CRMI-shaped; the operations are not implemented.Format is deliberately not the product. Open Quality aims to ingest whatever standard format a tool already emits, so nobody has to adopt anything of ours to publish here. What is missing from the ecosystem is not another way to package a measure. It is an open place to find one. See
spec/. -
Reason Health / ReasonHub and other CRMI-native platforms are authoring and syndication systems. Open Quality is deliberately the open, public-good end of the same space, and aims to interoperate, not overlap.
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The FHIR package registry distributes FHIR conformance artifacts, and does that well. It answers "where do I get this package." It is not built to answer "why is this measure slow," "does a missing HbA1c count as poor control," or "how did someone else read this denominator." Different problem, not a smaller one.
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NCQA's Digital Quality Implementers Community (DQIC) is a consensus effort focused, in NCQA's own description, first on CQL engines, with other tooling and languages as future work. Engines are well covered. Measures and analytics practice are not.
What Open Quality adds that isn't already covered: radical openness, first-class support for SQL and SQL-on-FHIR (not just FHIR-canonical artifacts), and the knowledge corpus of interpretation issues.
Being open source is also what makes the corpus possible. There is no HEDIS license to negotiate and no legacy vendor to pay for the right to discuss a measure in public.
Status
Pre-launch.
Local validation stops at Level 1, and so does the seeded corpus. Level 2 needs the deep validators, which do not exist yet.
Repository map
This is a single repository, laid out so the intent is legible at a glance.
Try it
Requires Node 22 and pnpm.
pnpm install
pnpm test
pnpm oq validate-all measures/cms-fhir-2026
Expected output:
Checked 69 packages, 0 below Level 1
That is 52 measures and the 17 shared CQL libraries they depend on, each published once.
Reading the corpus from a tool
There is no registry server, and a tool that wants to list or fetch packages does not need one. The whole read interface is one static document:
https://openquality.us/index.json
No credentials, no OAuth, no host for anyone to run. It lists every package with its
id, version, steward, data model, licence, conformance level, and the repository paths
of its manifest and artifacts, plus every knowledge entry. A client reads it, decides
what it wants, and fetches those paths from the raw base URL the document names.
The conformance level in that file is computed by running the same validator
oq validate runs, not asserted, and CI fails if the file drifts from the corpus it
describes.
ref is main, which moves. Pin a commit or tag and substitute it into raw if you
need the same bytes twice.
Connecting an agent or IDE (MCP)
The corpus is also served over the Model Context Protocol, so a coding agent can read a measure's code and the context around it while you work:
https://openquality.us/mcp
Streamable HTTP, read-only, no account or key. In Claude Code:
claude mcp add --transport http openquality https://openquality.us/mcp
It is listed in the official MCP Registry
as us.openquality/mcp. Configs for Cursor, VS Code and the MCP Inspector are at
openquality.us/mcp-setup.
Every result ends with the commit it was served from, the package license, and the
content policy, so the terms travel with the code into the agent's context. The
server reads only the files index.json lists. The hosted endpoint reads the
repository at the commit it was deployed from.
To run it locally over stdio, from npm:
npx -y @openquality/mcp # GitHub, main
npx -y @openquality/mcp --ref <sha> # GitHub, a fixed commit
npx -y @openquality/mcp --root <clone> # a local clone, no network
Using a measure in CQL Studio or another FHIR tool
A package can be emitted as a FHIR NPM package, which is the format CQL Studio loads, the FHIR package registry serves, and IG Publisher produces:
pnpm oq fhir-package measures/cms-fhir-2026/diabetes-glycemic-status-assessment-greater-than-9
Each CQL file becomes a Library resource carrying the CQL as a text/cql
attachment, with its include statements stated as depends-on. FHIR resources
the package already holds, such as a SQL-on-FHIR ViewDefinition, are packaged
as they are.
The resources are marked experimental and their canonical URLs point at
openquality.us rather than at the measure steward, because a repackaged copy is
not an authoritative publication of the logic. The tarball is byte-for-byte
reproducible, so its digest addresses its content.
What a package looks like
A package is a directory with an openquality.yaml manifest and the artifacts the
manifest declares.
id: cms/diabetes-glycemic-status-assessment-greater-than-9
version: 0.5.0
license: CC0-1.0
measurementPeriod: 2026
measure:
title: "Diabetes: Glycemic Status Assessment Greater Than 9%"
steward: National Committee for Quality Assurance
identifiers: [CMS122FHIR]
dataModel: qi-core
artifacts:
- path: cql/CMS122FHIRDiabetesAssessGreaterThan9Percent.cql
type: cql
valueSets:
- oid: 2.16.840.1.113883.3.464.1003.198.12.1013
url: http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.464.1003.198.12.1013
source: vsac
Trimmed from the real package in
measures/cms-fhir-2026/diabetes-glycemic-status-assessment-greater-than-9/,
which declares nine artifacts and nine value sets in full.
A package references value sets by OID and never embeds the expansions. This keeps VSAC and CPT licensed content out of the artifact, so the file is safe to publish.
dataModel is what makes shared SQL usable by anyone other than its author. SQL written
against an undeclared warehouse schema is unreadable to a stranger.
Conformance levels
Levels measure rigor, not FHIR adoption. A SQL-only package can reach the top. Most organizations doing quality measurement write SQL against a warehouse, not CQL. A level system that required FHIR to reach the top would exclude them.
- Level 0, Shared. Valid manifest, open license, at least one artifact. Any language.
- Level 1, Described. Declared data model, typed artifacts, resolvable value sets, and a README stating intent, known limitations, and provenance.
- Level 2, Verified. Deep validation passes for every artifact. CQL translates to ELM. FHIR resources validate against the CRMI and QI-Core profiles. SQL parses against its declared dialect and ships its schema.
Full definitions, including the CRMI mapping, are in spec/.
The knowledge corpus
The measures are half the value. The other half is what the community learns about them.
knowledge/ holds typed feedback attached to a measure and pinned to a
version — a question, an interpretation issue, a defect report, an implementation note, or
a validation result. "Known interpretation issues for CMS122" becomes a query instead of
an archaeology project.
This is also the contribution an employer will often approve when they will not approve releasing the SQL itself. The schema is built as a machine-readable superset of the categories in the ONC eCQM Issue Tracker, so the corpus is continuous with where implementers already file questions.
Content policy
Open licenses only. No HEDIS logic. No redistributed VSAC expansions. No CPT display descriptors, which are AMA licensed; a CPT code and code system may be referenced. Full rules per code system are in TERMINOLOGY.
NCQA holds copyright on the HEDIS specifications, so that logic cannot be published here. You can publish your own implementation written against a public specification. You can also publish test cases and review comments, which is often the part an employer will approve releasing even when they will not release the SQL.
The forbidden content scanner is a heuristic first filter. It will miss things and it will produce false positives. It is backed by a takedown process, not presented as a guarantee.
Get involved
Community is the point, and none of these ask you to publish code.
Everyone who has contributed so far arrived holding a problem rather than a package: a bug in the validator, a claim that was not true, or a use case the tool did not serve. That is the normal way in, not the exception.
- Bring a problem. Open the library, find a measure you have implemented, and use the links on it. Question, ambiguity, defect or test case, each opens a form with the measure and version already filled in. You do not need to be sure you are right. "I could not tell which of two readings was intended" is a complete contribution.
- Publish a measure package. See CONTRIBUTING.
- Review what others have published.
What the first reviewers found records what four outside readers caught in the first twenty days, what changed because of it, and what is still open. The open list is the short version of where help is worth most right now.
The measure and clinical-reasoning community mostly gathers on the FHIR Zulip
(#cql) and in the HL7 Clinical
Quality Information work group. We show up there too.
Please read the Code of Conduct and the Governance model. Governance is worth a look up front: Open Quality is founded and stewarded by FHIR IQ today, with a written commitment to broaden to community governance as it grows.
Not a measure steward
Open Quality is not a measure steward and is not affiliated with or endorsed by CMS, NCQA, or HL7. Seeded content is redistributed from public sources with provenance stated on each package.
License
The tooling is MIT. See LICENSE. Measure content keeps the license its manifest declares; the imported CMS eCQMs are CC0-1.0.
