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Per-workflow agent targeting

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Problem

Each ComfyUI browser tab connects to the orchestrator with a tab_id, but ComfyUI can have multiple workflow tabs open inside that browser tab. Graph tools (graph_get_state, graph_add_node, …) default to whichever workflow the user is currently viewing. If the user switches workflow tabs while the agent is working, edits land on the wrong graph.

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Solution

The orchestrator keeps a per-tab_id workflow target:

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Active-canvas constraint (#556/#571)

The panel has no way to read or mutate a non-active workflow’s graph: every graph executor runs against app.canvas.graph, and the panel’s pinned-target guard (#349/#186) fails closed with a “workflow mismatch” error whenever an injected workflow_path is not the workflow currently in view. Background editing of a non-active tab is therefore not supported. Consequently a pin is only honorable when its target is the active canvas. panel_set_workflow_target (and the panel-driven set_workflow_target event) validate at pin time via resolvePinTarget and:
  • fail closed if the workflow isn’t open (#259),
  • fail at pin time if it is open but not the active canvas (#556/#571) — never accept-then-defer,
  • canonicalize an honorable pin to the workflow’s stable key.
The injected workflow_path then acts as a guard: if the user later switches away, the next graph command fails loudly instead of silently editing the wrong graph.

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Orchestrator API

  • MCP tools: panel_get_workflow_target, panel_set_workflow_target
  • Bridge event (panel → orchestrator): { type: "set_workflow_target", tab_id, mode, path?, filename? }
  • Bridge push (orchestrator → panel): { type: "workflow_target", target }
  • Ack: { type: "ack", ok, kind: "workflow_target", target? }

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Command injection

When pinned, the orchestrator adds workflow_path to:
  • All graph_* commands
  • workflow_save, workflow_save_as, workflow_rename, workflow_close when path is omitted
Never injected on: workflow_list, workflow_new, workflow_open.

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Panel implementation (comfyui-mcp-panel)

Graph executors run against the active canvas (app.canvas.graph); the panel cannot address a non-active workflow document. So each executor:
  1. Reads optional workflow_path on the incoming { rid, cmd, … } frame.
  2. Treats it as a guard: if workflow_path does not identify the active canvas, it fails closed with a retryable “workflow mismatch” error (#349/#186) — it never blindly mutates the active graph under a mismatched pin.
  3. Otherwise applies the mutation on the active canvas.
Because background editing is not possible, the orchestrator rejects a background pin at pin time (see the active-canvas constraint above) so the mismatch guard is only ever a last line of defense (e.g. the user switches tabs after a valid pin), not the normal failure path.

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Files

  • src/services/workflow-target-store.ts — store + injection helper
  • src/orchestrator/panel-tools.ts — MCP tools + makePanelToolCtx injection
  • src/orchestrator/index.ts — bridge handler + hello sync