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Why Pulumi (not Terraform)?

ubx uses Pulumi as its runtime because:
  1. Output<T> type system — Pulumi’s Output<T> is the right primitive for Pending<T>. Terraform has no equivalent.
  2. Multi-language support — Pulumi providers work with TypeScript, Go, Python, Java.
  3. Automation API — Programmatic control over plan/apply without subprocess calls.
  4. Component Resources — First-class support for reusable component abstractions.
Terraform/OpenTofu is supported only as a migration source (ubx convert --from terraform).

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Why HCL-inspired syntax (not YAML)?

  • YAML is whitespace-sensitive and error-prone for complex nested structures
  • HCL is familiar to the largest IaC user base (Terraform)
  • Block-based syntax maps naturally to cloud resource declarations
  • Comments, string interpolation, and expressions are first-class

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Why a ~ sigil for Pending<T>?

The ~ prefix makes Pending<T> references visually distinct at a glance: 
engine   = "postgres"                        # Resolved — obvious
password = input.db_password                  # Resolved — obvious
host     = ~unit.aws_rds_instance.db.endpoint # Pending — obvious
Alternative syntaxes considered: ${} (clashes with interpolation), @{} (less readable), no prefix (ambiguous).

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Why single label for component?

# Two labels (old, confusing)
component "eks_platform" "main" { source = "..." }

# Single label (current, clear)
component "main" { source = "..." }
The first label was redundant — source already expresses the type. Single label is consistent with input, output, local.

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Why output not export?

export has TypeScript connotations. output is familiar to Terraform/OpenTofu users and matches the ubx output CLI command.

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Why no OPA for policies?

The policy block evaluates conditions at compile time using a simple boolean expression evaluator. This eliminates:
  • External OPA server dependency
  • Rego learning curve
  • Network calls during ubx validate
For complex compliance, consider OPA as a pre-commit hook.

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Why BYOK for AI features?

Bring Your Own Key (BYOK) means:
  • No ubx telemetry or data collection
  • Users control their Anthropic API spend
  • AI features work with any Anthropic-compatible endpoint
  • No dependency on Ubiquex infrastructure for AI functionality