Saving a Base64 Document to IBM BAW Embedded Document Store Using ECM Content Toolkit

When building integrations on IBM Business Automation Workflow (BAW), a common requirement is to programmatically save a document — received as a base64-encoded string — into the embedded BPM document store and associate it with a running process instance. This article walks through exactly how to do that using the ECM Content Toolkit’s Content Integration task inside a Service Flow.

Prerequisites

Before you start, make sure the Content Management (SYSCM) toolkit is added as a dependency to your process application:

Process App Settings → Toolkits → Add Content Management (SYSCM)

This toolkit provides the ECMContentStream, ECMProperty, and ECMMultiValue business objects you'll need.

Service Interface

Create a new Service Flow (or Integration Service) with the following input variables:

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Inputs:

• mimeType (String) — MIME type of the document (e.g. application/pdf)
• fileName (String) — Name of the document file (e.g. invoice.pdf)
• content (String) — Base64-encoded document content
• documentProperties (List of NameValuePair) — Optional custom metadata key-value pairs
• instanceId (String) — The process instance ID to associate the document with

Local (private) variables:

• contentStream (ECMContentStream)
• properties (List of ECMProperty)
• documentId (String)

Step 1 — Map Document Properties

Add a Script task to your service flow. This script builds the ECM property list from your documentProperties input and also injects the IBM_BPM_Document_ProcessInstanceId property — which is what links the document to the process instance.

function initProperty(name, value) {
  var property = new tw.object.ECMProperty();
  property.objectTypeId = name;
  property.value = value;
  return property;
}

tw.local.properties = new tw.object.listOf.ECMProperty();
var props = new tw.object.ECMMultiValue();
props.value = new tw.object.listOf.ANY();
for (var i = 0; i < tw.local.documentProperties.listLength; i++) {
  props.value[i] =
    tw.local.documentProperties[i].name +
    "," +
    tw.local.documentProperties[i].value;
}
tw.local.properties[0] = new tw.object.ECMProperty();
tw.local.properties[0].objectTypeId = "IBM_BPM_Document_Properties";
tw.local.properties[0].value = props;
var propInstanceId = initProperty(
  "IBM_BPM_Document_ProcessInstanceId",
  tw.local.instanceId
);
tw.local.properties.insertIntoList(0, propInstanceId);

What’s happening here?

• IBM_BPM_Document_ProcessInstanceId is the key property that tells BAW which process instance this document belongs to. Without it, the document will exist in the store but won't appear under the instance's document list.
• IBM_BPM_Document_Properties is a special multi-value ECM property that holds your custom metadata as comma-separated name,value pairs.

⚠️ Important: All custom properties passed via documentProperties must be packed into a singleIBM_BPM_Document_Properties ECMProperty entry using ECMMultiValue. You cannot create one ECMProperty per custom field — BAW only recognizes one IBM_BPM_Document_Properties entry per document, and adding multiple entries will cause only the last one to be persisted or result in an error. The loop in the script above handles this correctly by collecting all name-value pairs into a single ECMMultiValuebefore assigning it.

Step 2 — Build the Content Stream

Add a second Script task to construct the ECMContentStream object from your base64 input:

tw.local.contentStream = new tw.object.ECMContentStream();
tw.local.contentStream.content  = tw.local.content;   // base64-encoded string
tw.local.contentStream.mimeType = tw.local.mimeType;  // e.g. "application/pdf"
tw.local.contentStream.fileName = tw.local.fileName;  // e.g. "invoice.pdf"

The content field of ECMContentStream accepts a Base64-encoded UTF-8 string directly — no additional encoding or conversion is needed.

Step 3 — Create the Document via Content Integration Task

Add a Content Integration task to the canvas and configure it as follows:

• Server: BPM managed store
• Operation: Create document

Input Mapping

• documentTitle → tw.local.fileName
• contentStream → tw.local.contentStream
• objectType → "IBM_BPM_Document"
• properties → tw.local.properties

Output Mapping

• objectId → tw.local.documentId

The returned objectId is the unique identifier of the newly created document in the BPM store.

Complete Service Flow

[Start]
   ↓
[Script: Map Properties]
   ↓
[Script: Build Content Stream]
   ↓
[Content Integration: Create Document]
   ↓
[End]

The resulting documentId can be stored as a process variable or returned to the caller for reference.

Key Takeaways

• You don’t need to decode the base64 string manually. ECMContentStream.content accepts it as-is.
• The IBM_BPM_Document_ProcessInstanceId property is what links the document to an instance — don't skip it.
• All custom metadata must be packed into a single IBM_BPM_Document_Properties entry using ECMMultiValue — one entry per property will not work.
• The entire flow requires no REST calls — it’s fully handled through the Content Integration task and the SYSCM toolkit types.

Have questions or a different approach? Drop a comment below.