Meta Specification

In both the Job and Task specifications within Bacalhau, the Meta block is a versatile element used to attach arbitrary metadata. This metadata isn't utilized for filtering or categorizing jobs; there's a separate Labels block specifically designated for that purpose. Instead, the Meta block is instrumental for embedding additional information for operators or external systems, enhancing clarity and context.

Meta Parameters in Job and Task Specs

The Meta block is comprised of key-value pairs, with both keys and values being strings. These pairs aren't constrained by a predefined structure, offering flexibility for users to annotate jobs and tasks with diverse metadata.

User-Defined Metadata

Users can incorporate any arbitrary key-value pairs to convey descriptive information or context about the job or task.


"Meta": {
    "project": "frontend",
    "version": "1.2.5",
    "owner": "team-alpha",
    "environment": "development"
  1. project: Identifies the associated project.

  2. version: Specifies the version of the application or service.

  3. owner: Names the responsible team or individual.

  4. environment: Indicates the stage in the development lifecycle.

Auto-Generated Metadata by Bacalhau

Beyond user-defined metadata, Bacalhau automatically injects specific metadata keys for identification and security purposes.

Bacalhau Auto-Generated Keys:

  1. A unique identifier for the orchestrator that handled the job.

  2. The public key of the requester, aiding in security and validation.

  3. The ID for the client submitting the job, enhancing traceability.


"Meta": {
    "": "QmfZwnVWYjHSchAVxJqXn18Bvd1cpG2ATRYceBBvUGZf2f",
    "": "CAASpgIwggEiMA0GCSqG...BcyEhfEZKnAgMBAAE=",
    "": "dfadea67ab6d8c65761c3d879119e11f157923036f945d969d19a51066dc663a"

Implications and Utility

  1. Identification: The metadata aids in uniquely identifying jobs and tasks, connecting them to their originators and executors.

  2. Context Enhancement: Metadata can supplement jobs and tasks with additional data, offering insights and context that aren't captured by standard parameters.

  3. Security Enhancement: Auto-generated keys like the requester's public key contribute to the secure handling and execution of jobs and tasks.

While the Meta block is distinct from the Labels block used for filtering, its contribution to providing context, security, and traceability is integral in managing and understanding the diverse jobs and tasks within the Bacalhau ecosystem effectively.