Params

A param is a named, typed input to a whole workflow. Params turn a graph that does one thing into a graph that does a class of things.

Define them in ≔ params in the canvas topbar.

Declaring

Field	Meaning
`name`	Identifier. Letters, digits, `_`, `-`
`type`	`text`, `int`, `float`, `bool`, or `json`
`default`	Pre-filled value (optional)
`description`	Shown in the run form (optional)

Using

Reference a param anywhere in prompt text or a converter template:

Review the following change and list three risks.

Area: {{param:area}}
Diff:
{{input}}

Substitution happens at run time, before the node executes. Unknown placeholders are left visible rather than silently blanked. So a typo shows up in the output instead of vanishing.

Filling

Canvas. Press ▶ Run and threadle shows a form for every declared param, pre-filled with defaults and validated against each type before the run starts.

CLI. Pass them as flags:

threadle run <graphId> \
  --param area="authentication" \
  --param strict=true \
  --approve-all

Values are validated the same way in both paths. A bad int stops the run before any agent is called:

param "retries" not an int: "three"

Graph settings live next door

The ≔ panel also holds two run-wide settings that are not params:

Setting	Effect
parallelism	Max independent nodes executing at once (default 4). See Parallelism
spend ceiling (USD)	Abort the run when tracked spend reaches this ceiling. See Circuit breakers

Unused params are flagged

If a param is declared but never referenced, Graph lint says so:

parameter never referenced as {{param:area}}

Usually that means a renamed placeholder, not a spare param.

Patterns

One param, one spine. The bundled Starter workflow takes a single task param and threads it through plan, implement, and review stages. One input, three agents.

Params as switches. A bool param inside a converter template lets one graph produce a terse or verbose prompt without rewiring.

Params as data. A json param is validated as JSON before the run. Handy for feeding a structured list into an iterator.

Running. The run form
CLI. --param flags
Lanes & value types. The same type system on wires