Bulk export job failing with 400 on digital channel metadata

Struggling to figure out why the recording export job is failing for our digital channel streams. The standard voice recordings export fine to the S3 bucket, but the digital channel data (WhatsApp, Web Chat) triggers a validation error on the metadata payload.

We are using the Recording API v3.5.2 in the London region. The chain of custody metadata is required for legal discovery, so we cannot skip the custom fields. The job status returns FAILED with the message: Invalid metadata structure for digital channel type.

Here is the JSON payload we are sending in the bulk export request body:

{
 "export_job_id": "exp_job_998877",
 "destination": {
 "type": "S3",
 "bucket": "legal-discovery-eu-west-2",
 "prefix": "digital_channels/2023-10/"
 },
 "filters": {
 "media_type": ["DIGITAL_CHANNEL"],
 "start_time": "2023-10-01T00:00:00Z"
 },
 "metadata_inclusion": {
 "chain_of_custody": true,
 "custom_architect_variables": true,
 "participant_ids": true
 }
}

The S3 integration is verified and working. Is there a specific schema requirement for digital channel metadata that differs from voice? The documentation is vague on this point. Any insight on the correct structure would be appreciated.

It depends, but generally…

• Check the payload structure in your JMeter thread group.
• Ensure metadata is a flat object, not nested arrays.
• Verify no null values exist for required chain-of-custody fields.

The platform API rejects malformed JSON structures during bulk exports. Try logging the raw request body to spot syntax errors.

The easiest fix here is this is to simplify the payload structure before sending it to the API.

1. Flatten the metadata object to avoid nested arrays.
2. Remove any null values from the chain-of-custody fields.

The system validator rejects complex JSON structures during bulk jobs.

The problem here is…

Cause: the digital channel metadata schema doesn’t allow nested arrays or nulls for chain-of-custody fields. the API validator is strict. it fails on complex JSON.

Solution: flatten the object. remove nulls. here is a quick snippet to sanitize the payload before sending:

function sanitizeMetadata(data) {
 return Object.entries(data).reduce((acc, [key, val]) => {
 if (val !== null && val !== undefined) {
 acc[key] = Array.isArray(val) ? val.join(',') : val;
 }
 return acc;
 }, {});
}

this keeps the payload flat. the export job should pass validation then. also check your IdP clock skew if using OIDC tokens. slight drift causes 400s too. we saw this during a beta test. the token expired mid-job.

make sure the terraform state is clean too. stale refs cause conflicts. not directly related but good practice.

digital channels are finicky with metadata. voice is easier. just keep it simple.

If I remember correctly, the v3.5.2 schema enforces strict flat structures for digital metadata, so nested arrays will always trigger a 400.

Sanitize the payload before the bulk job starts.