File Reader

Overview

The File Reader node reads a file from a configured storage provider and emits its contents downstream. Use it when a workflow step depends on reading a stored artifact, uploaded input, or persisted battle result. Files may be returned as raw text or base64-encoded binary depending on the encoding setting. If the file is not found or access is denied, execution routes to the error output rather than halting the workflow.

Configuration

Field	Type	Required	Description
storage_provider	enum (local, s3, supabase)	Yes	Storage backend to read from. Must match the provider where the file was written.
file_path	string	Yes	Path or key of the file within the storage provider. Supports template variables (e.g. {{run.artifact_path}}).
encoding	enum (utf8, base64)	No	Output encoding for file contents. Defaults to utf8. Use base64 for binary files such as images or PDFs.
credential_id	string	No	ID of the stored credential to use when authenticating with the storage provider. Required for S3 and private Supabase buckets.
fail_on_missing	boolean	No	When true, routes to the error output if the file does not exist. When false, emits an empty string and continues on the output port. Defaults to true.

Inputs

Port	Type	Description
input	object	Trigger signal and optional runtime context. Any fields present are merged into template variable resolution for file_path.

Outputs

Port	Type	Description
output	object	Emitted on success. Contains file_content (string), file_path (string), byte_size (number), and encoding (string).
error	object	Emitted when the file cannot be read (not found, permission denied, provider unreachable). Contains error_code (string) and message (string).

Example

{
  "nodeType": "file_reader",
  "config": {
    "storage_provider": "s3",
    "file_path": "battles/{{run.battle_id}}/submission.txt",
    "encoding": "utf8",
    "credential_id": "cred_s3_prod_01",
    "fail_on_missing": true
  }
}