Migrating from Claude Sub-agents to duckflux

Claude Code's sub-agent system is powerful. You define specialized agents with focused prompts, restricted tools, and independent contexts. Claude decides when to delegate, spawns sub-agents in foreground or background, and synthesizes results. It works. But there's a design choice buried in the architecture that matters more than any individual feature: who decides what happens next? In Claude Sub-agents, the answer is the LLM. The parent agent reads your request, evaluates sub-agent descriptions, and decides which one to spawn. The routing logic lives in inference, not in config. This article explores why that matters, when it becomes a problem, and how duckflux offers an alternative where the orchestration is deterministic while the work inside each step stays as creative as the LLM needs to be. How Claude Sub-agents work Claude Sub-agents are markdown files with YAML frontmatter that define specialized AI assistants. Each sub-agent has its own system prompt, tool restrictions, mode