Workers Builds build_outcome is non-nullable in OpenAPI but null while running

[nicu-chiciuc]

The OpenAPI schema for builds_BuildOutcome permits only terminal string values. The live API returns builds_BuildResponse.build_outcome as null while builds_BuildResponse.status is running.

I verified both points against the current schema at commit 791663f57e4312d14bfef614efef61dea72a12a9.

Schema path:

#/components/schemas/builds_BuildOutcome

Response property:

#/components/schemas/builds_BuildResponse/properties/build_outcome

Published schema

{
  "type": "string",
  "example": "success",
  "enum": [
    "success",
    "fail",
    "skipped",
    "cancelled",
    "terminated"
  ]
}

Reproduction

Inspect the exact published definitions:

SCHEMA_COMMIT=791663f57e4312d14bfef614efef61dea72a12a9

curl -fsSL \
  "https://raw.githubusercontent.com/cloudflare/api-schemas/$SCHEMA_COMMIT/openapi.json" \
  | jq '{
      build_outcome: .components.schemas.builds_BuildOutcome,
      response_property: .components.schemas.builds_BuildResponse.properties.build_outcome
    }'

Start a Worker build. While builds_BuildResponse.status is running, call the build-list endpoint:

curl -fsS \
  "https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/builds/workers/$CLOUDFLARE_WORKER_TAG/builds?page=1&per_page=100" \
  -H "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
  | jq '[
      .result[]
      | select(.status == "running")
      | {
          status,
          build_outcome,
          stopped_on
        }
    ]'

Observed live response shape:

[
  {
    "status": "running",
    "build_outcome": null,
    "stopped_on": null
  }
]

This output includes only lifecycle fields. It does not expose account identifiers, Worker identifiers, build identifiers, environment variables, or credentials.

Validation

A strict Ajv validator generated from the published schema rejected the running builds_BuildResponse at:

/result/0/build_outcome

The validation errors were:

must be string
must be equal to one of the allowed values

After I changed only builds_BuildOutcome to permit null, the observed running response passed this part of validation.

This mismatch is independent of #46. That issue covers build_trigger_source and environment_variables in builds_BuildTriggerMetadataResponse. This report covers the top-level lifecycle field builds_BuildResponse.build_outcome.

Expected

One of these behaviors:

• builds_BuildOutcome permits null until the build has a terminal outcome.
• The API omits build_outcome until a terminal string is available.

Impact

Strict clients and runtime validators generated from cloudflare/api-schemas reject the full build-list response when it contains a builds_BuildResponse with status: "running". In our case, this made the current build appear unavailable until it finished, although the API correctly reported its status as running.