Steel Skill Creator

Turn a recurring web task into an agent skill. The user describes the task and one set of example inputs. You drive the task end-to-end twice in a real Steel browser (once with the example inputs, once with mutated inputs), capture both traces through the Steel CLI, author a parameterized SKILL.md, install it, and verify it on a third input set.

The user does not provide a session ID. You generate both sessions yourself.

The principle this skill is built on

Steel agent traces are already 80% of a SKILL.md. They contain stable selectors prioritized by quality (testId → id → aria → name → CSS), accessibleNames for every clicked element, page boundaries, idle gaps that mark wait points, and parameter values inline as URL query strings and form inputs. Your job is mostly reading two traces side by side and writing the parts that aren't there yet: the goal, the parameter names, the success criteria, and the right Steel session configuration (stealth, proxy, credentials, profiles) for production replay.

The reason you generate both traces yourself: parameter extraction is reliable when you can diff two runs of the same flow with different inputs. Anything that differs at corresponding positions is a parameter; anything identical is an invariant. You can't get that from a single trace without guessing, and asking the user to record twice doubles their effort. Better that you do it.

Do not try to handle every edge case programmatically. Use your judgment. The references/ directory tells you what to look for; the rest is reading code and writing code.

Prerequisites

• steel CLI is installed and authenticated for browser driving.
• The steel-browser skill is available — you'll use the same primitives (steel browser start, navigate, snapshot, click, fill, wait, etc.) to drive both recording sessions.
• The task is described clearly enough that you can execute it. If the description is too vague ("automate my browsing"), ask for specifics before doing anything else.