Job dependencies

Dependencies prevent a job from entering dispatch before its inputs are ready. PostgreSQL stores the job and its dependency edges in the enqueue transaction, so a rollback removes both.

const importId = await queue.enqueue("contacts.import", { source: "upload" });
await queue.enqueue("contacts.notify", { importId }, { dependencies: {
  prerequisiteJobIds: [importId], onSuccess: "release", onFailure: "fail", onCancellation: "cancel",
} });

The older prerequisiteJobId shorthand is deprecated because it hides the terminal policies.

For fan-in, declare every prerequisite and what each terminal outcome means:

The same Dependencies value accepts several prerequisite IDs for fan-in. TypeScript uses prerequisiteJobIds, Python uses prerequisite_job_ids, and Go uses PrerequisiteJobIDs.

The dependent remains blocked until every edge resolves. If policies disagree after fan-in, fail wins over cancel, and cancel wins over release, so concurrent completion order cannot change the result.

Inspect blocked work

Admin.getJob and Admin.listJobs expose prerequisiteJobIds, dependencyPolicy, and blockedReason. Admin.getDependencyLineage(jobId) returns retained edges in both directions, including policy, resolution, and release evidence. The dashboard exposes the same links and lets an operator open related tasks directly.

PostgreSQL bounds direct edges and downstream settlement work. A cycle or an oversized graph raises DependencyCycleError or DependencyLimitExceededError before unbounded work reaches dispatch.

Producers declare edges with EnqueueOptions.dependencies. PostgreSQL stores blocked work in job_runtime until its runAt gate and prerequisites allow a dependency_released transition. Queue.cancel can settle that graph, while Queue.health() reports Blocked work through the public Queue client.

Next

• Child jobs — delegate work from inside a handler
• Priority — order a dependent after release
• Dead letters — preserve terminal evidence

Exact dependency schema and lifecycle semantics: architecture reference.