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Interface: PlanInput

Defined in: packages/core/src/graph/plan.ts:34

Topological planner for the graph composition primitive.

Task A2 — pure string-level DAG math. No Processables, no Streams, no runtime hooks. The graph runner (A4) calls plan(...) once at construction to produce the execution order + predecessor / successor maps, then drives the DAG at runtime using the returned shape.

The planner is deliberately split from the runtime so it can also serve the web app's config-form compiler (apps/edge/src/lib/ pipeline-compile.ts in Phase C). Same algorithm, two entry points.

Algorithm:

  1. Validate — unknown nodes, duplicate edges, source with incoming
  2. Compute reachability from source (BFS). Unreachable nodes are silently pruned — matches the DIY runner's current behavior and the fluent API's "you can only build connected graphs" guarantee
  3. Detect cycles in the reachable subgraph via colored DFS; report the cycle path so errors are debuggable
  4. Topologically sort via Kahn's algorithm over the reachable subgraph
  5. Resolve the output node: explicit > unique sink > ambiguous (error)

Determinism: the planner preserves edge declaration order in predecessors and successors. That's load-bearing — in A4, multi- predecessor bots learn their input field names from the order edges were added (config form) or from merge() key order (fluent form). Shuffling would silently rename fields.

Properties​

edges​

edges: readonly object[]

Defined in: packages/core/src/graph/plan.ts:44

Directed edges. Order matters for multi-predecessor nodes — see the class comment on determinism.

nodes​

nodes: Iterable<string>

Defined in: packages/core/src/graph/plan.ts:40

All node ids in the graph. Iterable so the fluent API can hand in a Set and the config form can hand in Object.keys(nodes).

output?​

optional output?: string

Defined in: packages/core/src/graph/plan.ts:48

Explicit sink. Required when the reachable graph has multiple sinks; forbidden to be unreachable from source.

source​

source: string

Defined in: packages/core/src/graph/plan.ts:36

Root node that receives the graph's outer input.