Flow Control Nodes
Applies to: ChengOS v0.2.0+ ｜ Last verified: 2026-09-25 ｜ Source: crates/cheng-nodes/src/nodes/builtin/utils
These nodes decide where data goes and what shape it arrives in. utils/condition_router is the
deterministic branch — simple mode is one rule with a true/false pair of outputs, advanced mode is a
multi-rule switch with one output per branch. Reach for it before an LLM branch whenever the rule can
be written down. utils/to_items fans a single value out into items for downstream iteration,
utils/type_cast fixes type mismatches at a connection, utils/smart_var holds a named value you want
to reference from several places, and utils/delay paces calls against a rate-limited service.
Condition Router — utils/condition_router
Route by field conditions: supports operator comparison, dot nested path, Schema hint generation, enhanced fallback metadata
Inputs
| Field | Type | Required | Default | Description |
|---|
context | object (port) | — | null | Input AgentContext (optional). Connection port, not a form field. Control: code-editor |
response | string | — | "" | LLM response text (JSON format). Control: code-editor |
custom_data | string | — | null | Custom JSON data. Control: code-editor |
payload_source | enum | — | response | Select data extraction source. Control: select. Options: response (从 response 字段解析 JSON), context (从完整 context 序列化为 JSON), custom (从 custom_data 字段取值) |
branch_fields | array<object> | — | [] | Branch field list (click + to add; each entry auto-generates a corresponding output port) |
strict_mode | boolean | — | false | Error on JSON parse failure (false routes error reason to fallback output) |
generate_schema | boolean | — | false | Enable auto-generated JSON Schema hint output to schema_hint port (can connect to upstream LLM's system_prompt) |
mode | enum | — | advanced | Simple (If: one rule, True/False) or Advanced (Switch: multi-rule, multi-output). Control: select. Options: simple (If 模式：单条件，True / False 输出), advanced (Switch 模式：多规则多输出（默认，兼容旧行为）) |
match_policy | enum | — | all | First: stop at first match. All: output all matched branches (default). Control: select. Options: first (仅输出第一个命中的分支), all (所有命中的分支都输出（默认）) |
fallback_mode | enum | — | fallback_output | FallbackOutput: route to fallback_out (default). None: skip. Output0: route to first branch port. Control: select. Options: fallback_output (输出到 fallback_out 端口（默认）), none (不输出，下游自动跳过), output0 (输出到第一个分支端口) |
Outputs
| Field | Type | Description |
|---|
branch_outputs | array<any> (port) | Branch output list, corresponding 1:1 with branch_fields (AgentContext on match, null on miss). Connection port, not a form field. |
fallback_out | object | Fallback output (acts as 'False' in Simple mode). Fires when no branch rule matches. Includes diagnostic metadata. |
context_out | object | Legacy fallback output (use fallback_out instead). Mirrors fallback_out for backward compatibility. |
schema_hint | object (port) | Auto-generated structured output hint (can connect to upstream LLM node's system_prompt port). Connection port, not a form field. |
Smart Variable Node — utils/smart_var
Auto-detect text variables, dynamically generate ports, support full output and picked variable extraction
Inputs
| Field | Type | Required | Default | Description |
|---|
template | string | ✅ | — | Raw text (supports JSON/curl/YAML, etc.). Control: textarea |
extract_mode | enum | — | auto | Extract mode: auto=auto-detect key names, manual={{var}} syntax only. Control: select. Options: auto, manual |
output_vars | array<string> | — | [] | List of variables to include in output. Control: multi-select. Options loaded from ports |
Outputs
| Field | Type | Description |
|---|
full_text | string | Full text after variable substitution |
selected_vars | object | Picked variable key-value pairs |
all_variables | array<string> | All extracted variable names |
preview_content | string | Formatted preview content |
statistics | object | Variable extraction statistics |
To Items — utils/to_items
Normalize any input into a loop-ready items array for LoopContainer
Inputs
| Field | Type | Required | Default | Description |
|---|
input | any | — | — | Data to convert into loop items |
mode | enum | — | auto | How to convert the input. Control: select. Options: auto (Automatically detect input type.), array (Input is an array — pass through, normalizing each element.), single (Wrap any single value into a one-element array.), split_text (Split a string into text items.), refs (File / document / chunk reference passthrough — no content expansion.), object_values (Convert object key-value pairs into items.), range (Generate a numeric range as items.) |
chunkSize | integer | — | 500 | Characters per chunk when Split By = Chunk. Control: number |
maxItems | integer | — | 0 | Maximum number of items to emit (0 = unlimited). Control: number |
rangeEnd | integer | — | 0 | Range end (exclusive, Range mode). Control: number |
rangeStart | integer | — | 0 | Range start (inclusive, Range mode). Control: number |
rangeStep | integer | — | 1 | Step between consecutive range values. Control: number |
splitBy | enum | — | paragraph | Text split strategy (SplitText mode). Control: select. Options: paragraph (Split on blank lines (two consecutive newlines).), line (Split on every newline.), sentence (Heuristic sentence splitting (punctuation-based).), chunk (Fixed character chunk size.) |
Outputs
| Field | Type | Description |
|---|
items | any | Loop-ready items array |
count | integer | Number of items in the array |
mode_used | string | Conversion mode that was applied |
Type Cast — utils/type_cast
Convert between common port types, with first-class AgentContext support
Inputs
| Field | Type | Required | Default | Description |
|---|
agent_context | object (port) | — | null | Connect AgentContext-like object here. Connection port, not a form field. |
text | string (port) | — | null | Connect string/text output here. Connection port, not a form field. |
json | object (port) | — | null | Connect object output here. Connection port, not a form field. |
array | array<any> (port) | — | null | Connect array output here. Connection port, not a form field. |
integer | integer (port) | — | null | Connect integer output here. Connection port, not a form field. |
number | number (port) | — | null | Connect number output here. Connection port, not a form field. |
boolean | boolean (port) | — | null | Connect boolean output here. Connection port, not a form field. |
Outputs
| Field | Type | Description |
|---|
agent_context | object (port) | Converted AgentContext. Connection port, not a form field. |
text | string (port) | Converted string. Connection port, not a form field. |
json | object (port) | Converted object. Connection port, not a form field. |
array | array<any> (port) | Converted array. Connection port, not a form field. |
number | number (port) | Converted number. Connection port, not a form field. |
integer | integer (port) | Converted integer. Connection port, not a form field. |
boolean | boolean (port) | Converted boolean. Connection port, not a form field. |
source_type | string | Selected input source type |
Delay Node — utils/delay
Add delay in workflow, for testing pause and stop functionality
Inputs
| Field | Type | Required | Default | Description |
|---|
delay_type | enum | — | fixed | fixed, random range, until timestamp, until time of day, fixed with jitter, or exponential backoff. Control: select. Options: fixed (固定时长延迟), random_range (随机区间延迟), until_timestamp (延迟到绝对时间戳), until_time_of_day (延迟到某个本地时间), fixed_with_jitter (固定延迟并附加抖动), exponential_backoff (指数退避) |
delay_value | integer | — | 5 | Delay time value (used with unit). Control: number |
delay_unit | enum | — | seconds | Delay time unit: milliseconds or seconds. Control: select. Options: milliseconds (毫秒), seconds (秒), minutes (分钟), hours (小时) |
max_delay_value | integer | — | null | Upper bound for random range delay. Control: number |
target_timestamp | string | — | null | RFC3339 timestamp or local datetime interpreted with timezone. Control: datetime-local |
time_of_day | string | — | null | Local target time in HH:MM or HH:MM:SS |
timezone | string | — | UTC | IANA timezone for local datetime interpretation; defaults to UTC |
jitter_percent | integer | — | null | Maximum +/- jitter percentage for fixed_with_jitter mode. Control: number |
attempt | integer | — | null | Zero-based attempt number for exponential_backoff mode. Control: number |
initial_delay_value | integer | — | null | Initial delay value for exponential_backoff mode. Control: number |
max_backoff_value | integer | — | null | Maximum delay value for exponential_backoff mode. Control: number |
multiplier | number | — | null | Growth multiplier for exponential_backoff mode. Control: number |
log_message | string | — | null | Log message: output before and after delay |
passthrough | any | — | null | Passthrough data: forwarded as-is to output port |
Outputs
| Field | Type | Description |
|---|
completed | boolean | Whether delay completed normally |
actual_delay_ms | integer | Actual delay duration (milliseconds) |
passthrough | any | Passthrough data from input |
log_message | string | Passthrough log message from input |
context | object | AgentContext combining log_message and passthrough |
info | object | Detailed delay execution info |
Next steps