Input & Output Nodes
Applies to: ChengOS v0.2.0+ ｜ Last verified: 2026-09-25 ｜ Source: crates/cheng-nodes/src/nodes/builtin/io
These are the nodes that put data into a workflow. io/input_text carries literal text or a JSON
literal you type into the canvas; io/file_upload turns an upload into durable artifact references;
io/read_file reads a path the server can already see. The distinction that matters is inline value
versus artifact: an artifact port hands downstream nodes a reference instead of the bytes, so large
payloads never travel through the execution record. io/file_upload deliberately does no OCR,
parsing, or transcription — it routes each upload to a typed artifact port and leaves the conversion
to the media nodes.
Text Input — io/input_text
Multi-line text / JSON input, outputs text, JSON value and AgentContext
Inputs
| Field | Type | Required | Default | Description |
|---|
text | string | — | "" | Plain text content (supports multi-line input). Control: textarea |
json_text | string | — | "" | JSON format content (ignored when empty). Control: code-editor |
Outputs
| Field | Type | Description |
|---|
text | string | Raw content of the text field (String) |
length | integer | Character length of the text field (Number) |
json_value | any | Parsed result of json_text (null if JSON is invalid) |
context | object (port) | AgentContext output (can connect directly to Agent / Output nodes). Connection port, not a form field. |
File Upload — io/file_upload
Route uploaded files to durable artifact references for documents, images, audio and video. OCR/parsing/transcription are dedicated downstream nodes.
Inputs
| Field | Type | Required | Default | Description |
|---|
files_json | array<any> | object | string | — | null | Upload files via picker or drag-and-drop; returns artifact references. Control: file-upload |
allowed_category | enum | — | auto | Restrict allowed file category. Control: select. Options: auto (自动检测), image (图片), document (文档), audio (音频), video (视频), other (其他) |
max_file_size_mb | integer | — | 50 | Maximum size per file (MB). Control: number |
enable_ocr | boolean | — | false | Deprecated and ignored. Connect image_artifact to io/ocr instead. Control: switch |
parse_documents | boolean | — | false | Deprecated and ignored. Connect document_artifact to io/document_to_text instead. Control: switch |
llm_inline_max_bytes | integer | — | 0 | 已废弃：不再产生需要离线存储的内联正文。保留以兼容旧工作流字段。 |
Outputs
| Field | Type | Description |
|---|
artifacts | array<object> (port) | All uploaded files as durable artifact references. Connection port, not a form field. |
first_artifact | object (port) | Reference to the first uploaded file. Connection port, not a form field. |
document_artifact | object (port) | First document artifact; connect to io/document_to_text.artifact. Connection port, not a form field. |
image_artifact | object (port) | First image artifact; connect to io/ocr.artifact. Connection port, not a form field. |
audio_artifact | object (port) | First audio artifact; connect to io/speech_to_text.artifact. Connection port, not a form field. |
video_artifact | object (port) | First video artifact; connect to io/video_extract_audio.artifact. Connection port, not a form field. |
file_count | integer | Number of files routed |
total_size | integer | Total size of all files (bytes) |
errors | array<string> | Error messages during processing |
llm_text | string (port) | Bounded manifest (filename, type, size, artifact URI) for ai/llm.user_message. Connection port, not a form field. |
document_base64 | string | Deprecated: see document_artifact. Always None. |
document_filename | string | Deprecated. Always None. |
document_text | string | Deprecated. Always None. |
audio_base64 | string | Deprecated: see audio_artifact. Always None. |
audio_filename | string | Deprecated. Always None. |
video_file_path | string | Deprecated: see video_artifact. Always None. |
image_base64 | string | Deprecated: see image_artifact. Always None. |
image_filename | string | Deprecated. Always None. |
file_paths | string | Deprecated. Always None. |
chat_input_raw | string | Deprecated. Always None. |
user_message_rich | object | Deprecated: rich multimodal parts are materialized at the LLM node. Always None. |
ocr_text | string | Deprecated: OCR is a dedicated node now. Always None. |
ocr_structured_json | string | Deprecated. Always None. |
ocr_status | string | Deprecated. Always None. |
ocr_results_json | string | Deprecated. Always None. |
Read File — io/read_file
Read a bounded range of a file as plain text from an artifact reference or local path. Connect to LLM text inputs.
Inputs
| Field | Type | Required | Default | Description |
|---|
artifact | object (port) | — | null | Artifact reference to read (preferred over file_path). Connection port, not a form field. |
file_path | string | — | null | Absolute or relative local path (legacy; mutually exclusive with artifact). Control: text |
prefix | string | — | null | Optional prefix prepended to content |
suffix | string | — | null | Optional suffix appended to content |
start_byte | integer | — | 0 | Byte offset to start reading from |
max_bytes | integer | — | 16384 | Maximum bytes to read in this window (default 16 KiB, hard cap 1 MiB) |
start_line | integer | — | null | 1-based start line (enables line mode) |
max_lines | integer | — | null | Maximum lines to read in line mode |
Outputs
| Field | Type | Description |
|---|
content | string | Bounded plain-text content (with prefix/suffix) |
source_artifact | object | Artifact that was read, if any |
bytes_read | integer | 实际读取的字节数 |
total_bytes | integer | 文件总字节数 |
truncated | boolean | Whether more content exists beyond this window |
file_path | string | Resolved path (legacy file_path input only) |
error | string | 错误信息；成功时为 null |
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