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Reserved Names in FlowDrop

This document lists all reserved names in FlowDrop that cannot be used by plugins for custom parameters, outputs, or configuration keys.

Overview

FlowDrop reserves certain names for system functionality. Plugin developers should avoid using these names in their getParameterSchema() and getOutputSchema() methods to prevent conflicts.

Reserved Port Names

Input Ports

Name Purpose Status
input Unified input port - accepts all connectable parameters as a single JSON object Active
config Reserved for unified config port - will accept all configurable parameters as JSON Future
trigger Flow control signal - triggers node execution Active

Output Ports

Name Purpose Status
output Unified output port - provides all exposed outputs as a single JSON object Active
trigger Flow control signal - emitted when node completes execution Active
active_branches Gateway output - specifies which branch(es) should be executed (see below) Active

active_branches Output

The active_branches output is a magic output name that gateway node processors must return. It indicates which branch(es) the orchestrator should activate for downstream execution.

Type: string (single branch) or comma-separated string (multiple branches)

Example: 

return [
  "active_branches" => "true",  // Single branch
  // or
  "active_branches" => "a,b",   // Multiple branches (parallel gateway)
];

The orchestrator performs case-insensitive matching between active_branches and the branch name values from the branches input parameter.

See Gateway Nodes and Branching for complete documentation.

Reserved Configuration Keys

These keys are reserved in the node's configSchema and cannot be used by plugins:

Name Purpose Status
instanceTitle Override the default node title for a specific instance Active
instanceDescription Override the default node description for a specific instance Active
branches Gateway node conditional output paths (see below) Active
nodeType Visual type selection when multiple types are supported Active
dynamicInputs User-defined dynamic input ports Active
dynamicOutputs User-defined dynamic output ports Active

branches Configuration Key

The branches key is special for gateway-type nodes (visual_type: gateway). It defines the available conditional output paths:

{
  "branches": [
    { "name": "True", "value": true },
    { "name": "False", "value": false }
  ]
}
  • name: Display name that becomes the output port name (e.g., "True" → {nodeId}-output-True)
  • value: The value to match against when determining which branch is active

The frontend dynamically generates output ports based on this configuration. The processor must return active_branches output indicating which branch(es) were activated.

See Gateway Nodes and Branching for complete documentation.

Reserved Internal Parameters

Parameters with names starting with double underscore (__) are reserved for internal system use. These bypass normal validation and are injected by the orchestrator:

Name Purpose
__state__ Graph state for stategraph orchestrator
__messages__ Message history for chat workflows
__data__ Shared data store
__iterator__ Iterator state for ForEach loops
__current_item__ Current item in ForEach iteration
__interrupt_id__ Interrupt ID for human-in-the-loop resume

Validation

During plugin discovery, FlowDrop will log a warning if a plugin defines:

  • A parameter with a reserved input port name (input, config, trigger)
  • An output with a reserved output port name (output, trigger)

This helps plugin developers identify potential conflicts early.

Unified Ports Feature

The unified input and output ports are optional features that site builders can enable per node type:

Unified Input Port (input)

When enabled via unified_input_exposed: true:

  • Appears as an additional input port with type json
  • Accepts all connectable parameters as a single JSON object
  • Individual port connections take precedence over values in the unified input
  • Non-connectable parameters are filtered out (security)

Unified Output Port (output)

When enabled via unified_output_exposed: true:

  • Appears as an additional output port with type json
  • Provides all exposed outputs as a single JSON object
  • Non-exposed outputs are filtered out (security)
  • Coexists with individual output ports

Example Usage

# Simple data pass-through
upstream.output → processor.input → downstream.input

# Selective override
data_source.output → calculator.input (provides base data)
config_node.precision → calculator.precision (overrides precision)

Best Practices for Plugin Developers

  1. Avoid reserved names - Do not use input, output, config, trigger, branches, or active_branches as parameter or output names.

  2. Use descriptive names - Instead of generic names, use specific names like text_input, result_data, api_response.

  3. Check for conflicts - Review the reserved names list when designing new plugins.

  4. Internal parameters - Never define parameters starting with __ (double underscore) as these are reserved for system use.

See Also