Fixing Supabase PDF Uploads: Invalid Key & Korean Filenames

Hey there, fellow developers and tech enthusiasts! Ever run into that pesky "Invalid key" error when trying to upload a PDF to Supabase Storage, especially when dealing with filenames that aren't just good old English letters? If you've been banging your head against the wall trying to figure out why your perfectly named Korean PDF file refuses to upload, you've landed in the right spot! We're diving deep into this common but super frustrating issue, specifically focusing on how Korean filenames can trip up Supabase Storage and, more importantly, how we can fix it once and for all. Supabase is an incredible open-source backend-as-a-service platform that makes building applications a breeze with its PostgreSQL database, authentication, real-time subscriptions, and, of course, Storage capabilities. It's fantastic for quickly spinning up projects, from simple apps to complex enterprise solutions. However, like any powerful tool, it sometimes has its quirks, and handling diverse character sets in file paths can be one of them. This article isn't just about pointing out a problem; it's about giving you actionable, practical solutions that you can implement right away to ensure your application handles all types of filenames gracefully. We'll explore the technical nitty-gritty of why this error occurs, walk you through how to reproduce it, and then lay out several robust strategies to overcome it, making your Supabase Storage uploads bulletproof, no matter what language your filenames speak. So, buckle up, guys, because we're about to make your PDF uploads smooth sailing!

Understanding the Supabase PDF Upload Failure: The 'Invalid Key' Mystery

Alright, let's get right into the heart of the matter: the "Invalid key" error during PDF uploads to Supabase Storage. This isn't just a random error message; it's a specific complaint from the storage system that the path or name you're trying to use for your file isn't acceptable. Imagine trying to mail a letter, but the address you wrote contains characters the postal service doesn't recognize – that's essentially what's happening here. When you attempt to upload a PDF file, especially one with a filename containing non-ASCII characters like Korean (Hangul), Supabase Storage throws a fit, returning this dreaded error. The immediate consequence, as reported, is that your PDF file fails to upload, and your application might only manage to store the associated text content, leaving you without the crucial visual document. This graceful degradation to text-only storage is a mitigation, but it’s far from the ideal behavior when you expect the entire PDF to be accessible. It means your users won't be able to download or view the original PDF, undermining the functionality you designed. The error message itself, something like StorageApiError: Invalid key: documents/9e5811aa-cd47-4a7b-8391-b940da91d984/1765444485886_GGP_단체상해보험_가이드.pdf, gives us a big clue. See that GGP_단체상해보험_가이드.pdf part? That's where the problem lies. The core issue often stems from how various systems handle file paths and character encoding. Many cloud storage providers, including components of Supabase Storage, are optimized for and sometimes mandate the use of characters within the basic ASCII set for file keys/paths to ensure universal compatibility and avoid parsing issues across different platforms and programming languages. When a filename deviates from this expectation by including characters outside of the ASCII range, such as Korean Hangul, the system identifies it as an "Invalid key" and rejects the upload. This behavior isn't unique to Supabase; it's a common challenge when integrating systems that operate with different character set assumptions. Understanding this fundamental conflict is the first step towards crafting a robust solution.

Replicating the Issue: A Step-by-Step Guide

To truly grasp this bug, let's walk through the steps to reproduce it. This isn't just for the developers fixing it, but for anyone who wants to understand exactly what's going on. Picture this: you're in the Mentor Dashboard of your application, and you've navigated to the PDF tab. Everything seems to be running smoothly. Now, the crucial part: you select a PDF file. But not just any PDF file – you pick one with a filename that includes Korean characters. For instance, let's use the example from the bug report: GGP_단체상해보험_가이드.pdf. This file, while perfectly valid on your local operating system, contains Hangul characters (단체상해보험_가이드) that are the culprits here. After selecting this file, you confidently click the "교육 자료 생성" (Create Training Material) button, expecting a seamless upload and creation process. You've done this a hundred times with English-named files, right? But this time, instead of the success message, you're greeted with an error. The application attempts to send this file to Supabase Storage, and that's when the magic (or rather, the lack thereof) happens. The upload fails specifically because the file's path, constructed with the Korean filename, is deemed an "Invalid key" by the Supabase Storage API. The error message you'd typically see popping up would be something like, PDF 저장 실패: 업로드 실패: Invalid key: documents/9e5811aa-cd47-4a7b-8391-b940da91d984/1765444485886_GGP_단체상해보험_가이드.pdf. 텍스트만 저장됩니다. which translates to: PDF Save Failed: Upload Failed: Invalid key: documents/.../GGP_단체상해보험_가이드.pdf. Only text will be saved. This immediate feedback confirms that the system rejected the filename due to the presence of the Korean characters. The part about "텍스트만 저장됩니다" is key; it means the application might have successfully extracted and stored the text content of the PDF in your database, but the actual PDF document itself is not in storage, rendering it inaccessible for download or viewing. This exact scenario highlights the critical need for proper filename handling and encoding within your application before interacting with external storage services like Supabase. It’s a classic case of system incompatibility that, thankfully, has several straightforward solutions.

Deep Dive into the 'Invalid Key' Root Cause: Character Encoding

So, what's really going on behind the scenes with this "Invalid key" error? The core problem, guys, lies in the Supabase Storage API's handling of file paths (keys) and character encoding. Many cloud storage systems, including Supabase Storage, are primarily designed to work with ASCII characters in their object keys. ASCII (American Standard Code for Information Interchange) is a character encoding standard for electronic communication, representing text in computers. It's a relatively small set of characters (0-127) that includes basic Latin letters, numbers, and common symbols. While perfectly sufficient for English filenames, it simply doesn't include characters from other languages, such as Korean Hangul, Japanese Kanji, Arabic script, or Cyrillic. When your application attempts to send a filename like GGP_단체상해보험_가이드.pdf to Supabase Storage, the Hangul characters (단체상해보험_가이드) fall outside the ASCII range. The Supabase Storage system, upon receiving this key, flags it as invalid because it doesn't conform to its expected character set for object paths. This isn't necessarily a flaw in Supabase itself, but rather a common architectural choice in distributed systems to maintain maximum compatibility and avoid complex encoding/decoding issues across diverse environments and client applications. If the storage system were to arbitrarily accept any character, it could lead to ambiguities when different operating systems or programming languages try to interpret those paths, potentially causing file access problems, security vulnerabilities, or simply making path resolution extremely difficult. Furthermore, URL standards and best practices often recommend encoding non-ASCII characters in paths to ensure they are transmitted and interpreted correctly across the web. Supabase's API, likely adhering to these web standards, rejects unencoded non-ASCII characters in file paths to maintain consistency and robustness. Therefore, the "Invalid key" error is a protective measure, indicating that the submitted file path does not meet the necessary criteria for storage within their system. Understanding this fundamental limitation is crucial for crafting an effective and lasting solution, as it highlights that the filenames need to be transformed into an ASCII-compatible format before being sent to the storage service.

Expected vs. Actual Behavior: Bridging the Gap

When we're building applications, especially those dealing with file uploads, our expected behavior is almost always universal compatibility. Ideally, we should be able to upload any valid file, regardless of its filename's language or character set, and have it stored seamlessly. For a user, it's a fundamental expectation: if I name my file 보고서.pdf (report.pdf in Korean), it should upload just like report.pdf. We expect the underlying system to handle the complexities of character encoding, internationalization, and path compatibility without us having to jump through hoops. We envision a scenario where the application intelligently processes the filename, perhaps by automatically encoding it, and then sends it off to Supabase Storage, which accepts it without a fuss. We'd get a success message, and the PDF would be available for viewing or download, exactly as uploaded. However, the actual behavior paints a very different, and much more frustrating, picture. Instead of a smooth upload, we encounter the dreaded "Invalid key" error. This error signifies that Supabase Storage has rejected the file because of its filename. The file itself might be perfectly fine, but its moniker, specifically the non-ASCII characters within it, is the dealbreaker. This leads to a graceful degradation where only the text content of the PDF is stored in the database, while the actual binary PDF file is left in limbo – not uploaded to Supabase Storage. So, while your database record might indicate that a PDF was processed, the physical document isn't where it should be. This discrepancy between expected and actual behavior creates a significant user experience problem and a functional gap in the application. Users can't access their original documents, and developers are left with a broken link between their database and storage. Bridging this gap requires us to actively manage the filename encoding process within our application, ensuring that what we send to Supabase Storage adheres to its compatibility requirements, thereby transforming the actual behavior to match our desired, seamless expected behavior.

Empowering Solutions: How to Fix Korean Filename Uploads

Alright, folks, now for the good stuff – the solutions! We've identified the problem, understood its root cause, and now it's time to arm ourselves with practical ways to conquer this "Invalid key" issue. The key, no pun intended, is to ensure that the filename (or the path) we send to Supabase Storage is ASCII-compatible. We've got a few solid options here, each with its own pros and cons, and we'll be focusing these changes primarily within the uploadPdfToStorage function in src/utils/storage.js. Get ready to make your PDF uploads bulletproof!

Solution Option A: The Power of URL Encoding

Our first and often simplest solution is to leverage the power of URL encoding using a function like encodeURIComponent. Guys, this is a web standard, and it's super effective! What encodeURIComponent does is take a string (like your Korean filename) and replaces special characters, including non-ASCII characters, with one or more hexadecimal escape sequences. For example, a Korean character might become something like %ED%95%9C. This transformation makes the filename entirely ASCII-compatible, which Supabase Storage will happily accept as a valid key. When you later retrieve the file, you can simply decodeURIComponent to get the original Korean filename back for display to the user. This approach is excellent because it preserves the original filename's semantic meaning while ensuring compatibility with the storage system. Implementing this would involve modifying the uploadPdfToStorage function. Instead of directly using the raw originalFilename for the storage path, you would first process it through encodeURIComponent(originalFilename). This ensures that the generated storage key, which looks something like documents/uuid/timestamp_GGP_%EB%8B%A8%EC%B2%B4%EC%83%81%ED%95%B4%EB%B3%B4%ED%97%98_%EA%B0%80%EC%9D%B4%EB%93%9C.pdf, is valid. The main benefit here is simplicity and direct preservation of the original filename in an encoded format within the storage path itself. The primary con might be that if you browse your Supabase Storage bucket directly, the filenames will appear encoded, which can be a bit harder to read at a glance. However, for programmatic access, this is a highly robust and widely accepted method for handling non-ASCII characters in URLs and file paths. It's often the first line of defense against character encoding issues and should definitely be considered as your go-to solution for its balance of simplicity and effectiveness.

Solution Option B: UUIDs and Metadata Magic

Next up, we have a more robust and arguably cleaner solution: replacing the filename with a UUID (Universally Unique Identifier) and storing the original filename in metadata. This approach completely sidesteps any character encoding issues with the file path because a UUID is always an ASCII-compatible string (e.g., 9e5811aa-cd47-4a7b-8391-b940da91d984). Think of it this way, instead of trying to make the original filename fit the storage system's rules, you give the file a totally new, guaranteed-valid, and unique name for storage purposes. The beauty here is that you then save the actual original filename (GGP_단체상해보험_가이드.pdf) as metadata associated with the stored file in Supabase. Supabase Storage allows you to attach custom metadata to objects, which is perfect for this use case. When you need to display the file to a user or allow them to download it, you retrieve the file from storage using its UUID key and then use the stored metadata to present the user with the original, human-readable Korean filename. This method has several significant advantages. First, it guarantees unique file paths, preventing potential naming collisions even if two users upload files with the exact same original filename. Second, it completely eliminates any concerns about character encoding in the storage key, making your uploads incredibly resilient. Third, it keeps your storage bucket looking clean and organized with uniform UUIDs, while still providing the original name when needed. Implementation would involve generating a UUID (or incorporating the existing UUID from your database record, as seen in the error path) and using it as the primary component of your storage key. Then, when calling the Supabase Storage upload function, you would pass an options object including userMetadata: { originalName: originalFilename }. When retrieving, you'd fetch the file and then access file.metadata.originalName. The only real downside is that it adds a slight layer of abstraction, meaning you always need to consult the metadata to get the human-friendly name, rather than inferring it directly from the storage path. However, for mission-critical applications where reliability and uniqueness are paramount, this is often the preferred strategy, providing a clean separation between internal storage identifiers and user-facing names.

Solution Option C: Transliteration or Character Stripping

Alright, guys, this last option, transliteration or character stripping, is a bit more of a last resort or a specific choice for certain scenarios. While viable, it's generally less ideal than the previous two because it involves altering or losing parts of the original filename's meaning. Transliteration means converting characters from one script to another – in our case, converting Korean Hangul characters into their Roman (Latin) approximations. For example, 단체상해보험_가이드 might become something like danchaesanghaebohom_gaideu. This process can be complex to implement accurately, as there are often multiple valid Romanizations for a single Korean word, and it requires a dedicated library or robust custom logic. The benefit is that the filename becomes ASCII-compatible and still somewhat readable to someone familiar with the transliteration rules. The major drawback, however, is the potential for loss of precise meaning or ambiguity, especially for non-Korean speakers who might struggle to connect the Romanized version back to the original Hangul. Alternatively, character stripping simply involves removing all non-ASCII characters from the filename. So, GGP_단체상해보험_가이드.pdf might become GGP_.pdf or GGP_pdf if underscores are also stripped, which is clearly problematic as it destroys the filename's utility. Both transliteration and stripping compromise the integrity of the original filename, which is generally something we want to avoid. If your primary goal is to preserve the exact original filename and ensure maximum clarity for users, options A (URL Encoding) or B (UUIDs with Metadata) are vastly superior. Option C might be considered in very specific edge cases where filename readability in the storage system's console is prioritized over perfect original filename preservation, or if there are extremely strict limitations on storage key formats that even URL encoding can't fully satisfy (though this is rare with modern cloud storage). For most applications, however, we recommend sticking with the first two options for their robustness and better preservation of information, ensuring a much better user experience.

Putting It All Together: Implementation & Environment Details

Now that we've covered the various solutions, let's talk about where and how to implement these fixes within your existing codebase. So, where do we actually do this, you ask? Based on the provided bug report, the critical place to focus our attention is within the src/utils/storage.js file, specifically targeting the uploadPdfToStorage function. This function is the central point responsible for interacting with the Supabase Storage API for PDF uploads. Any filename manipulation or metadata attachment should happen right here, before the actual upload call is made. Inside this function, you'll likely find where the storage path (key) is constructed. This is the exact spot where you'll apply encodeURIComponent to your filename (Option A), or generate a UUID and prepare the metadata (Option B), or implement transliteration (Option C). Furthermore, the bug report also points to src/features/content/create/components/ContentInputPanel.jsx as the PDF upload calling point. While the primary logic for filename handling should reside in storage.js to keep your utilities clean and reusable, ContentInputPanel.jsx is where the uploadPdfToStorage function is invoked. This means you might need to ensure that any originalFilename passed to uploadPdfToStorage is the correct one, and potentially handle the response or error messages appropriately after the storage.js function has processed the upload. For example, if you implement Option B, the ContentInputPanel might need to be aware that the displayed filename for the user comes from the metadata, not necessarily the raw storage key. It’s about creating a harmonious flow between your UI component and your backend utility. By centralizing the filename processing logic, you ensure consistency and easier maintenance across your application, making future updates or bug fixes much simpler to manage. Remember, well-structured code is always your best friend!

Environment & Version Specifics

Finally, let's briefly touch upon the environment details provided. The bug was reported on Version 2.24.0 of the application, using the Chrome browser, and interacting with the Supabase Storage API. While the core problem of non-ASCII characters in storage keys is generally platform-agnostic and applies to many cloud storage services, knowing the specific context is always helpful for troubleshooting and verifying fixes. The solutions we've discussed – URL encoding, UUIDs with metadata, or transliteration – are fundamental programming practices and should be effective regardless of minor version changes in your application or browser. However, it's always crucial to thoroughly test any implemented fix within your exact environment. What works in development might sometimes reveal subtle edge cases in production, especially when dealing with various user inputs and network conditions. For instance, ensuring that encodeURIComponent correctly handles all possible Korean characters across different system locales is important, though generally well-established. Similarly, verifying that Supabase's metadata capabilities are fully functional and reliably store and retrieve your original filenames is key for Option B. The fact that the issue is observed in Chrome suggests that it's not a browser-specific rendering or encoding problem on the client side, but rather a server-side (Supabase Storage API) rejection of the submitted key. This reinforces our focus on modifying the filename before it leaves your application's control and hits the Supabase API. So, while these solutions are robust, a little extra testing in your specific version and environment will ensure everything runs flawlessly, giving you and your users peace of mind. Consistent testing, folks, is what makes a great application truly exceptional!

Alright, folks, that's a wrap on tackling the frustrating "Invalid key" error with Korean filenames in Supabase Storage! We’ve navigated through the complexities of character encoding, dissected the problem, and, most importantly, laid out actionable strategies to make your PDF uploads rock-solid. From the straightforward elegance of URL encoding (encodeURIComponent) to the robust uniqueness of UUIDs combined with metadata, and even a quick look at transliteration, you now have a toolkit to handle these challenges. Remember, the goal is always to provide a seamless and intuitive experience for your users, regardless of the language their files are named in. Implementing these fixes in your uploadPdfToStorage function within src/utils/storage.js will not only resolve this specific bug but also make your application more resilient and globally friendly. It's a small change with a huge impact on user satisfaction and the overall quality of your application. So go ahead, implement these solutions, test them thoroughly in your environment, and say goodbye to those "Invalid key" headaches! Keep building awesome stuff, and make sure your applications are ready for the world. Happy coding!