Routes, branches and joins

Separate where execution goes from the conditions a node needs before it can begin.

Routes and readiness

to sends an activation to another node. needs declares one-time readiness requirements. A dependency does not by itself replace an explicit route.

Rattish: 1

Workflow:
  name: Two reports

Node prepare:
  type: write-file
  path: reports/prepared.txt
  content: Ready
  to:
    - left
    - right

Node left:
  type: write-file
  path: reports/left.txt
  content: Left result
  needs: prepare
  to: join

Node right:
  type: write-file
  path: reports/right.txt
  content: Right result
  needs: prepare
  to: join

Node join:
  type: write-file
  path: reports/done.txt
  content: Both branches are ready.
  needs:
    - left
    - right
  finish: pass

The outgoing routes make both branches eligible. A route target with no needs also runs when the workflow starts, so give each target needs on its source to run it only after that source; the compiler warns with RATTISH_ROUTE_TARGET_AUTO_STARTS otherwise. The join waits for its declared readiness conditions. Do not use a dependency on an unreachable branch: the compiler checks whether the required node can participate in the activation lineage.

Conditional routes

Routes can have when predicates and an otherwise fallback. All matching conditional routes are eligible. A list is not a first-match switch. otherwise matches only when no conditional route from that completion matched; unconditional routes fire independently.

For operation failures, set allow-fail: true before routing when failed. Without it, the compiler rejects the route as unreachable (RATTISH_UNREACHABLE_FAILURE_ROUTE).

Rattish: 1

Workflow:
  name: Check repository status

Node check:
  type: bash-command
  command: git status --short
  allow-fail: true
  to:
    - record-error when failed
    - record-success otherwise

Node record-error:
  type: write-file
  path: reports/status.txt
  content: Could not inspect repository status.
  needs: check
  finish: fail

Node record-success:
  type: write-file
  path: reports/status.txt
  content: Repository status checked.
  needs: check
  finish: pass

Structured output predicates such as node.review.output.approved require a successful producer and a declared compatible output schema. They do not read an agent's prose as a Boolean.

Cycles and limits

A route can return to an earlier node. Set a workflow or node max-runs limit, a timeout, or both so a repair/review cycle cannot repeat forever accidentally. retry-count repeats an operation attempt inside a node run; a routed cycle creates additional node runs.

Start and finish

start: true is an optional start assertion and presentation hint; it cannot have needs. finish: pass and finish: fail mark endpoints and prohibit outgoing routes. Use these fields instead of inventing start, pass, or fail node types.

See Loops, Inputs and bindings, and Runs.