Knowledge Base Data Storage Shows 0 MB on Sandbox Plan After Uploading Documents

[MP-tsunemoto]

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Content

Summary

I have been testing the Knowledge Base behavior on the Sandbox (Free) plan, and I noticed that the “Knowledge Base Data Storage” under Settings → Billing does not increase at all. It stays at 0 MB, even after uploading several documents.

I would like to confirm whether this is expected behavior and how the storage usage is actually calculated.

Background

I am working on a project where users save selected past conversation examples into the Knowledge Base.
To evaluate which Dify plan fits this use case, we are testing how the 50 MB Knowledge Data Storage limit behaves in the Sandbox plan.

However, we cannot observe any updates in the data storage usage after uploading documents.

Steps to Reproduce

1. Go to Knowledge Base
2. Upload several documents (e.g., .txt or .csv files with randomized sample content)
3. Ensure documents are ingested and chunked successfully
4. Go to Settings → Billing → Knowledge Base Data Storage
5. The usage remains at 0 MB, regardless of file size or quantity

Questions

1. How is “Knowledge Base Data Storage” calculated in the Sandbox plan?

   • Raw file size?
   • Total chunk size?
   • Embedding vector storage?
   • Something else?

2. Is the storage usage updated immediately after upload, or does it follow a scheduled process?

3. Is there a reference for how large uploaded files must be to reach the 50 MB limit?

4. For use cases involving frequent uploads of small text files, is the displayed storage usage expected to remain at 0 MB?

Additional Notes

• I could not find documentation describing how storage counting works or when usage is updated.
• All uploaded files were processed normally (chunked and searchable).
• This question is for clarification so we can choose the appropriate plan for our project.

Thank you!

[dosubot[bot]]

Hi @MP-tsunemoto! I'm Dosu and I’m helping the dify team.

Here's what I found:

The way "Knowledge Base Data Storage" is calculated and updated in the Sandbox plan isn't defined in Dify's public codebase or documentation. Instead, Dify fetches usage and limits from an external billing backend, which handles the actual measurement and reporting. The frontend simply displays the numbers it receives from the billing API—there's no logic in the repo that calculates storage based on raw file size, chunk size, or embedding size, nor is there evidence of immediate or scheduled updates after uploads. The UI mentions that only documents with "High Quality" indexing mode consume storage, but doesn't specify how much or how it's measured. There’s also no reference for how large files must be to reach the 50 MB limit, or whether small uploads will always show 0 MB usage in the Sandbox plan.

For more precise details on calculation and update timing, you’d need info from Dify’s official support or documentation outside the public repositories. If you want to test the limits, try uploading larger files or using "High Quality" indexing and monitor the Billing panel for changes.

Relevant code references:

• FeatureService: usage and limits fetched from billing API
• Frontend: displays vectorSpace and documentsUploadQuota from backend
• UI text: only "High Quality" indexing mode consumes storage

To reply, just mention @dosu.

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[MP-tsunemoto]

Thanks @dosu.

Additional information:

I uploaded multiple files close to the 15 MB per-file upload limit.
Even with several large uploads, the “Knowledge Base Data Storage” value in Billing stays at 0 MB.

This happens with both:

• Normal indexing mode
• High Quality indexing mode

Since the UI states that High Quality indexing should consume storage, this behavior seems inconsistent.

Questions based on this observation:

• Is storage metering disabled on Sandbox?
• Does the billing backend ignore certain file types or indexing modes?
• Is the usage meter updated only under specific conditions or intervals?

If this can be forwarded to the billing/backend team for clarification, that would be helpful.

[dosubot[bot]]

Based on the code and documentation, storage metering for Knowledge Base Data Storage—including usage calculation, update intervals, and plan-specific behavior—is handled entirely by the external billing backend. The Dify backend and frontend simply display the usage and limits they receive from the billing API; there is no logic in the public codebase that disables metering for the Sandbox plan, ignores file types or indexing modes, or controls update timing. Any behavior like always showing 0 MB used, delayed updates, or ignoring certain uploads would be determined by the billing backend, not by Dify itself. For clarification on metering logic or Sandbox-specific rules, the billing/backend team would need to provide details.
Relevant code: FeatureService and BillingService, Frontend billing utils.

To reply, just mention @dosu.

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[MP-tsunemoto]

Thanks @dosu.

Based on your explanation, it seems that all metering behavior is handled by the external billing backend.

However, in my tests, even when uploading multiple near-15 MB files and using High Quality indexing mode, the reported usage remains 0 MB. If the frontend only reflects values from the billing backend, this suggests that either:

1. Storage metering is not active for Sandbox, or
2. The billing backend is not calculating usage for these uploads, or
3. Usage updates are gated behind conditions not documented.

Since this behavior directly affects plan selection for my use case, could you escalate this to the billing/backend team to confirm whether Sandbox metering is intentionally disabled or not functioning as expected?

Let me know if additional test cases or screenshots would help.

[dosubot[bot]]

Everything in the public repo confirms that storage metering and usage reporting for Knowledge Base Data Storage is handled by the external billing backend, and there’s no logic in Dify’s backend or frontend that disables or alters metering for the Sandbox plan. Your experience—usage staying at 0 MB after large uploads, even with High Quality indexing—matches what other users have reported in both Sandbox and Professional plans, suggesting this may be a backend or cloud environment issue rather than a plan-specific restriction or file type problem (see related GitHub issue).

There’s no documentation or code that explains thresholds, update timing, or conditions for usage updates in Sandbox. Escalation to the billing/backend team is outside the scope of public repo support, but I’m flagging this for maintainers in case internal escalation is needed. If maintainers request more details, your offer to provide test cases or screenshots will be helpful. If there’s any update or clarification from the internal team, I’ll share it here.

To reply, just mention @dosu.

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