The Block · T4 Orchestration

Workflow vs agent

Last reviewed 21 Oct 2026by Pratima Chainani

In a workflow, LLM calls follow a path your code decides. In an agent, the model decides its own next step and which tools to use, in a loop.

LangGraph’s documentation puts it plainly: “Workflows have predetermined code paths and are designed to operate in a certain order,” while “Agents are dynamic and define their own processes and tool usage.”

Frameworks now ship five workflow patterns as building blocks: prompt chaining, routing, parallelisation, orchestrator–worker and evaluator–optimiser. Many systems marketed as agents are one of these.

Practitioners lean predictable. In Stack Overflow’s 2026 pulse survey, 69% of developers run a single agent and 68% prefer predictable single-agent setups to complex multi-agent ones.

Common misread

If it calls an LLM, it’s an agent.

If code decides the path, it’s a workflow. Often the better choice.

For your code

Draw the control flow before you pick a framework. Mark every step where the model, not your code, chooses what happens next.

For your roadmap

Ask vendors where the model decides, and how they test those points.

Sources

  1. LangGraph docs, Workflows and agents · accessed Oct 2026
  2. Stack Overflow, Agents on a leash (pulse survey, n = 1,100) · 27 May 2026