What is late binding?
Late binding is what makes a recorded path reusable rather than a one-off. Three token families are resolved by three different owners at three different times: {{secret:NAME}} by the vault inside the browser at fill time, {{var:NAME}} from per-tenant entity values captured after a run, and {{param:NAME}} by the caller on each invocation. A skill is only account-independent when all three are late-bound.
Why it matters
Without it, a compiled skill freezes whatever literal the compile run happened to type — so a "post a comment" skill re-posts the same sentence forever. Late binding is also a safety property: a replay refuses to run with a token still unresolved rather than substituting a stale value.