(registered 2024-04-17, last updated 2024-04-17)

Media type name: application

Media subtype name: cwl+yaml

Required parameters: N/A.

Optional parameters: N.A.

Encoding considerations: binary

Security considerations: This media type represents a CWL documents encoded using a subset of YAML. CWL parsers should take the same security precautions applicable for YAML to avoid arbitrary code execution and memory exhaustion; See Section 4 of RFC 9512. CWL documents typically reference software containers and executors of CWL documents should evaluate the security of third party containers before downloading or executing them. Executing CWL documents with any combination of third-party data or containers can lead to arbitrary code execution and resource exhaustion. CWL executors should have resource limits, logging, and other measures to control and monitor usage. See

https://cwe.mitre.org/data/definitions/502.html
https://cwe.mitre.org/data/definitions/73.html
https://cwe.mitre.org/data/definitions/410.html
https://cwe.mitre.org/data/definitions/641.html

CWL documents do not include digital signatures nor encryption of the workflow descriptions themselves. Users with data integrity, originator authenticity, and data confidentiality concerns with respect to the workflow descriptions themselves should address those concerns separately.

Interoperability considerations: The CWL standards include extensive conformance tests https://w3id.org/cwl/v1.2/#Running_the_CWL_conformance_tests

Published specification: https://w3id.org/cwl

Specific versions of the CWL standards:

https://w3id.org/cwl/v1.2
https://w3id.org/cwl/v1.1
https://w3id.org/cwl/v1.0

Applications which use this media: CWL has been used to exchange command line tool and workflow definitions by many researchers and scientists since the publication of version 1.0 in 2016. See https://www.commonwl.org/gallery/ for a list of public sector adopters across multiple domains and countries.

Fragment identifier considerations: Fragment identifiers in CWL URIs are defined in https://w3id.org/cwl/v1.0/SchemaSalad.html#Identifier_resolution

The use of fragment identifiers in CWL URIs are to refer to specific parts of the document, their use should not change the result from a (HTTP) retrieval operation.

Restrictions on usage: N/A

Additional information:

1. Deprecated alias names for this type: None
2. Magic number(s): See entry under "Other Information & Comments"
3. File extension(s): .cwl.yaml
4. Macintosh file type code: N/A
5. Object Identifiers: N/A

General Comments: Related Media types: application/cwl, application/cwl+json

Magic Numbers: All CWL document have the US-ASCII string "cwlVersion" (99 119 108 86 101 114 115 105 111 110) as a key in the topmost YAML/JSON dictionary.

Academic citation:

To reference the Common Workflow Language and the CWL project in scholarly work, please use the following citation:

Michael R. Crusoe, Sanne Abeln, Alexandru Iosup, Peter Amstutz, John Chilton, Nebojša Tijanić, Hervé Ménager, Stian Soiland-Reyes, Bogdan Gavrilović, Carole Goble, and The CWL Community. 2022. Methods Included: Standardizing Computational Reuse and Portability with the Common Workflow Language. Commun. ACM 65, 6 (June 2022), 54–63. https://doi.org/10.1145/3486897

To reference the CWL standards in scholary work, please use the following citation inclusive of the DOI:

Peter Amstutz, Michael R. Crusoe, Nebojša Tijanić (editors), Brad Chapman, John Chilton, Michael Heuer, Andrey Kartashov, Dan Leehr, Hervé Ménager, Maya Nedeljkovich, Matt Scales, Stian Soiland-Reyes, Luka Stojanovic (2016): Common Workflow Language, v1.0. Specification, Common Workflow Language working group. https://w3id.org/cwl/v1.0/ https://doi.org/10.6084/m9.figshare.3115156.v2

Person to contact for further information:

1. Name: Michael R. Crusoe
2. Email: mrc&commonwl.org

Intended usage: COMMON

CWL documents are widely distributed.

Author/Change controller: The CWL Project is currently part of Software Freedom Conservancy, Inc.; a USA based USA 501(c)(3) non-profit working in the public interest.

The CWL Leadership Team can be reached via commonworkflowlanguage&sfconservancy.org