OHDSI ATLAS Data Source Inventory (WebAPI)

Find out which OMOP data sources an OHDSI ATLAS server exposes, in about five seconds. Give this Actor the WebAPI root of an ATLAS deployment you are allowed to query and it returns one row per configured data source: its key, name, SQL dialect and which daimons (CDM, Vocabulary, Results) it carries. It reads metadata only. It never reads patient records, person-level data or cohort results.

The same Actor can also list server info, saved cohort definitions and concept sets, and search the OMOP vocabulary. Those modes are optional; start with the cheap source inventory below.

Quick start: inventory the OHDSI public demo server

1. Click Try for free. The input form opens already filled in.
2. Keep the prefilled values. This is the exact input of our last successful cloud run:

{
  "baseUrl": ["https://atlas-demo.ohdsi.org/WebAPI"],
  "mode": "sources",
  "query": "aspirin",
  "maxRecords": 25
}

query is ignored in sources mode; it is only used by vocabulary-search.

3. Click Start. That run finished in about 5 seconds and returned 5 rows (5 billed events).
4. Open the Output tab and export as CSV, JSON or Excel. To inventory your own deployment, replace baseUrl with its WebAPI root.

What the output looks like

These 5 rows come from that cloud run on the public demo server (WebAPI 2.14.0). Provenance columns and the _raw copy are left out here for width.

sourceKey	name	sourceDialect	daimonTypes	hasCDM	hasVocabulary	hasResults
ATLASPROD	Network prevalence counts	postgresql	CDM, Vocabulary, Results	true	true	true
CEM	Common Evidence Model	postgresql	Vocabulary, CEM, CEMResults	false	true	false
OHDSIEVIDNET	Evidence network counts	postgresql	CDM, Vocabulary, Results	true	true	true
SYNPUF1K	SYNPUF 1K	postgresql	CDM, Vocabulary, Results, Temp	true	true	true
SYNPUF5PCT	SYNPUF 5%	postgresql	CDM, Vocabulary, Results, Temp	true	true	true

Every row also carries _source (the base URL you gave), _mode, _endpoint, _requestUrl, _webApiVersion and _buildTimestamp, so a multi-server export stays traceable.

Using the columns

• Filter hasVocabulary = true to see which sourceKey values you can pass to vocabulary-search.
• daimonCount and daimonTypes show at a glance which sources are full CDM databases and which are vocabulary- or evidence-only.
• The table has one column set for all five modes. Columns that belong to another mode (for example conceptId in a sources run) are empty. In CSV exports, drop the empty columns and _raw for a clean sheet.
• Epoch-millisecond date fields such as createdDate, modifiedDate and concept validity dates are converted to ISO-8601 UTC. _buildTimestamp is passed through as the server reports it.

How much does it cost?

You pay per row returned, with no start fee. The current price is $0.0005 per record on the Apify free plan and drops to $0.00025 on the top subscription tier.

• The quick start above: 5 rows × $0.0005 = $0.0025.
• maxRecords is a hard cap on billed rows across all hosts. At 25 you can never pay more than $0.0125 on the free plan.
• You pay only per record; platform compute is included in that price.

Other modes (optional)

Mode	One row per	WebAPI endpoint
sources	configured OMOP data source, with daimons	/source/sources
info	server (version, build, security/Solr flags)	/info
cohortdefinitions	saved cohort / phenotype definition	/cohortdefinition
conceptsets	saved concept set	/conceptset
vocabulary-search	OMOP concept matching query	/vocabulary/{sourceKey}/search

cohortdefinitions and conceptsets return definitions (names, descriptions, timestamps, tags), not the patients in a cohort.

Vocabulary search is the heavy mode. On the demo server a term like aspirin matches tens of thousands of concepts, the server does not paginate, and a request can take 10 to 80 seconds. Set maxRecords to the number of rows you actually want to pay for, for example:

{
  "baseUrl": ["https://atlas-demo.ohdsi.org/WebAPI"],
  "mode": "vocabulary-search",
  "query": "aspirin",
  "maxRecords": 25
}

Leave sourceKey empty and the Actor picks the first source with a Vocabulary daimon.

Input fields

Field	Required	Description
baseUrl	yes	One or more WebAPI root URLs. Some servers mount at /WebAPI, others behind a proxy at /atlas/WebAPI; give the full root and the Actor appends the endpoints. Pasted the ATLAS address from your browser instead (e.g. https://atlas-demo.ohdsi.org/#/home)? The Actor drops the #/… part and, if that page is not the API, tries <site>/WebAPI once before any row is written, and logs which root it used. If nothing answers, the run stops with no rows and no charge, and its status names the …/WebAPI/info address to open in your browser: JSON there means that is your root; a login or web page means the server is private or not a WebAPI.
mode		One of the five modes. Default sources.
query		Search term, used only by vocabulary-search.
sourceKey		Vocabulary source for vocabulary-search. Auto-discovered if empty.
maxRecords		Cap on total rows (and billed events) across hosts. Default 1000; the form prefills 25.
bearerToken		OAuth2 bearer token for a security-enabled server you have an account on. Never logged.
extraHeaders		Extra request headers as a JSON object, if your deployment requires them.

Which servers work

• Public ATLAS/WebAPI servers that answer these endpoints without login, such as https://atlas-demo.ohdsi.org/WebAPI. The demo server holds synthetic and aggregate reference data.
• Your own or your organization's deployment, when it is reachable from Apify's cloud and you have access. For a security-enabled server, pass the token your account was issued.

The Actor does not bypass login, firewalls or permissions. A server on a private network, a server that refuses the request, or a WebAPI build with different endpoints will not return rows. Unreachable hosts are skipped with a warning; if no host returns any row the run fails (exit code 91) and nothing is billed. Each request has a 150-second budget so a stalled server cannot hang the run.

Notes

• Several hosts in baseUrl give you a cross-server inventory in one run; _source tells the rows apart.
• OHDSI, OMOP, ATLAS and WebAPI are projects of the OHDSI community. This Actor is an independent client of the published WebAPI and is not affiliated with OHDSI.
• Found a server it can't read, or need another endpoint? Open an issue on the Issues tab.