FlameInTheDark/templating-guide

Use this skill when the task is about {{ ... }} templates in node configuration.

Use Template Syntax Correctly

• Write templates as {{path.to.value}}.
• Treat input as the full current payload.
• Access nested objects with dot syntax such as {{input.response.status}}.
• Access arrays with zero-based indexes such as {{input.items[0]}}.
• Use executed-node lookups as {{$('node-id').path.to.value}} when you need data from a specific earlier node in the same run.
• Expect rendered objects and arrays to become JSON strings when inserted into text fields.

Know The Runtime Context

• input is always available.
• Top-level input keys are also exposed directly, so {{status}} may work when input.status exists.
• secret exposes stored secrets at runtime, such as {{secret.api_token}}.
• $('node-id') resolves to the decoded output object from that node's completed execution in the current run.
• Prefer {{input...}} when clarity matters.
• Cross-node selectors only work after the referenced node has already executed in the current run.
• Missing paths, missing node IDs, or not-yet-executed node lookups cause template rendering errors rather than quietly returning partial data.

Understand Pipeline Parameter Passing

• action:pipeline_run uses config.params as a templated string field.
• After templating, config.params must be valid JSON that decodes to an object.
• If action:pipeline_run config.params is empty, the current input map is passed through to the called pipeline.
• tool:pipeline_run passes the called pipeline input as a normal object, not as a raw JSON string.
• Custom tool:pipeline_run arguments are exposed inside the called pipeline under arguments.<name>.

Use Common Patterns

• Pass the whole payload through:

leave action:pipeline_run config.params empty

• Pass a shaped object:

{"request":"{{input.message.content}}","ticket":"{{arguments.ticket}}"}

• Reuse a specific upstream node output:

{{$('action:http-1775583878229').response.status_code}}

• Mix current input, secrets, and upstream node output:

{"status":"{{$('action:http-1775583878229').response.status_code}}","token":"{{secret.api_token}}","message":"{{input.message.content}}"}

• Return the current payload:

{{input}}

Keep Templates Separate From Expr Logic

• Use template syntax for string/config fields.
• Use expr syntax in logic:condition and logic:switch expressions.
• Do not wrap expr logic in {{ ... }} unless the field explicitly expects a text template.