scenario-labs / scenario-workflow-authoring

Scenario Workflow Authoring

Overview

A workflow has two representations: editor_info (the editable node graph: nodes, edges, inputKeys) and flow (the compiled runnable form). Authoring through MCP means writing the whole editor_info document: there are no per-node editing tools; every change is a read, modify, write of the full graph through workflow_create or workflow_update. Never hand-write flow: workflow_publish compiles editor_info into it and flips status to ready. Editing a ready workflow's editor_info leaves the stale flow running until you publish again.

Read [references/editor-info.md](references/editor-info.md) before writing any graph: it holds the node type vocabulary, the node choice doctrine (when an llm node is legitimate), the edge direction rule, per-node data contracts, and a validated minimal example. Create, update, publish, copy and delete live in the tool catalog (scenario_tools_search plus the matching executor, see the scenario skill). workflows_list, workflow_get and workflow_run are direct tools: scope and dry_run go in their top-level arguments, never an executor wrapper. Running and pricing: the scenario-workflows skill. If a sibling skill named here is missing from your available skills, ask the user to install it (npx skills add scenario-labs/skills --skill <name>); unattended, proceed from tool schemas and flag the gap.

Quick reference

workflow_create is two calls under the hood: a failed create may still have created a draft whose id is in the error. Recover with workflow_update on that id; re-creating duplicates. Seed step 1 with workflow_get: it returns the full graph of any workflow whose id you have, public ones included (an id or app URL the user supplies, or your own team's from workflows_list). To find a public template, use search with target="workflows", public=true, a keyword query, limit=3, and your scope; for example, query="image" with raw filter: 'status = "ready"'. Read ids from workflows, then fetch the chosen graph with workflow_get; search hits are summaries, not graph documents. Workflow search supports keyword text and filters only, so omit image and semantic options. Use workflows_list for browsing your saved workflows. [scripts/fetch_workflow_examples.py](scripts/fetch_workflow_examples.py) bulk-exports trimmed featured-workflow graphs for maintainers (setup in its header).

Worked example: a text-to-image app

1. recommend with capability: "txt2img" and the user's brief as prompt, following the scenario skill's next_step discipline, then model_schema_get: its input names become the model node's handle names, and its required flag marks what must be wired. Use search instead when the user names a model.
2. Author editor_info: text1 with data.isInput: true, model1 with type: "model", data.modelId and data.isOutput: true, one edge from model1's input to text1's output (edges name the downstream node as source, see the reference), inputKeys: ["text1"].
3. workflow_create with name, editor_info, and inputs_definition naming text1 as a string input. The published input key is the node id, which is why run inputs have names like text1.
4. workflow_publish, then workflow_run with dry_run=true to validate and price. Fix the graph and re-publish if validation fails.

One output per item needs a loop

A multiple-asset input wired straight into a generative model's reference field is one generation conditioned on every item at once: ten product shots in come back as one image blending them, not ten edits. Field names and cardinality are per model, so read them off model_schema_get (array: true marks a list), and read the field's description as well: a few utility tools take a list and return one output per item, which needs no loop. When each item needs its own result, put the model inside a forEach over the list and read the outputs from the forEachEnd (wiring in the reference's forEach section); keep the direct wiring only when the items are meant as joint references for a single output. Inside the loop the current item feeds an array field as a one-item list. forEach runs one billed model job per item, but the dry run prices one iteration whatever the list length (observed: one quote for one or two items, twice that billed for two), so multiply the quote by the item count before quoting the user.

Migrating a graph from another node tool

A pipeline exported by Weavy, ComfyUI, or another node editor does not import: only Scenario's own export round-trips. It is translated node by node, then created, published, and dry-run as above. The mapping table, member resolution, and the report the user gets are in [references/foreign-graph-import.md](references/foreign-graph-import.md); read it before touching such an export, since its first rule is to reduce the file to a table locally rather than paste it into the conversation.

Common mistakes

• Writing UI palette names as node types: persisted types are the camelCase vocabulary in the reference, and every generator is type: "model".
• Wiring edges producer to consumer: persisted edges point the other way.
• Expecting an editor_info update to change a live app without re-publishing.
• Retrying a failed workflow_create with a second create instead of workflow_update on the id from the error.
• Wiring a batch of assets into one model input and expecting one output per item: that is one generation over all of them; loop with forEach.
• Publishing with no pins: at least one data.isInput node listed in inputKeys and one data.isOutput node.
• Gating a text node in front of a builder or model: a branch skips only the node wired to its handle, so the consumer stays pending and the job never completes. Gate the node that does the work, or use a CEL ternary for conditional prompt text, per the reference's ifElse section.
• Double-quoted CEL literals: they evaluate but corrupt the canvas editor, single quotes only.
• Sending workflow_id to workflow_copy: get, update, publish, run and delete take workflow_id, but copy takes source_workflow_id; the copy inherits everything verbatim and needs its own publish.