When building no-code apps, API errors can disrupt functionality, frustrate users, and create development headaches. These issues often stem from problems like invalid requests, authentication failures, or server-side glitches. Here's what you need to know:
- 400 Bad Request: Caused by malformed JSON, missing fields, or unsupported ID formats. Use tools like JSONLint to validate your requests.
- 401/403 Authentication Errors: Result from incorrect credentials or insufficient permissions. Double-check headers, refresh tokens, and verify API access levels.
- 404 Not Found: Happens when endpoints are incorrect, IDs are invalid, or deprecated API versions are used. Confirm endpoint paths and test with tools like Postman.
- Timeouts, Rate Limits, 5xx Errors: Triggered by slow responses or exceeding request limits. Implement retry logic and optimize API calls to reduce load.
Using tools like Adalo's AnyData API Generator can simplify debugging by providing real-time error messages and structured troubleshooting steps. Fixing these issues ensures smoother app performance and a better user experience.
Common API Error Codes: Causes and Fixes for No-Code Apps
Common REST API Response Errors
400 Bad Request Errors
A 400 Bad Request error happens when the server can't process your request due to an issue on the client side. In Adalo, these errors often show up while testing a Custom Action or loading an External Collection, pointing to something being wrong or incomplete in your request.
What Causes 400 Errors in No-Code Apps
One of the most common reasons is malformed JSON - this can include missing braces, quotes, or commas. Another frequent issue is incorrect or missing headers, such as failing to set Content-Type to application/json. If you're using dynamic URLs with special characters, URL encoding errors might arise because the server can't interpret invalid characters.
In Adalo, unsupported ID formats are a well-known cause of 400 errors. Adalo External Collections only work with numeric IDs, so if your API uses text-based IDs or UUIDs like abc-123, the connection will fail. Additionally, if required API fields are left out, your request will be rejected.
Each of these problems requires specific adjustments, which are outlined below.
How to Fix 400 Errors
Start by validating your JSON using tools like JSONLint or Postman to catch structural errors such as missing brackets or trailing commas before making the API call. Next, double-check your headers to ensure they’re correctly formatted - your Authorization header should follow the format Bearer [API_KEY], and Content-Type must be set to application/json.
If you're troubleshooting, replace dynamic variables with static values to figure out whether the issue lies in the data format or the API structure. For External Collections, confirm that the Results Key matches the top-level key in the API's JSON response. For example, Airtable uses the key records to parse data correctly. If the problem persists, simplify your request by removing optional parameters and sending only the required fields to identify the root cause.
| Common Cause | Specific Example | Recommended Fix |
|---|---|---|
| Malformed JSON | Missing a closing brace } in the body |
Use a JSON validator (e.g., JSONLint) to check the structure |
| Unsupported ID Type | Using abc-123 (UUID) in a numeric field |
Ensure IDs are strictly numeric as required by Adalo |
| Wrong HTTP Method | Using POST for an update instead of PATCH |
Use the correct HTTP method per API documentation |
| Missing Headers | No Authorization: Bearer [Key] header |
Add all required headers to your API setup |
| URL Encoding Issues | Special characters in URL parameters | Adjust URL encoding settings appropriately |
401 and 403 Authentication Errors
401 Unauthorized and 403 Forbidden errors both stop your API requests, but they fail for different reasons. A 401 error means the server doesn't recognize who you are - your credentials might be missing, incorrect, or formatted improperly. On the other hand, a 403 error happens when the server knows your identity but denies access because you don't have permission to perform the requested action or access the resource.
What Causes Authentication Errors
Building on the discussion about 400 errors, authentication problems stem from various issues. For Adalo, the most frequent cause of 401 errors is incorrect header formatting. Even a hidden whitespace in the API key can cause trouble. Another common reason is using expired or revoked tokens. For example, if you've changed the password on an external service or regenerated an API key, the connection will fail.
403 errors, however, are typically caused by insufficient permissions rather than invalid credentials. These issues often arise due to plan limitations or database restrictions. For instance, if Collection Permissions are not set to allow the API to read or write data, your request will be blocked - even if you supply a valid key. Additionally, certain fields, like formula fields or synced tables, are inherently read-only and will return a 403 if you try to modify them.
How to Fix Authentication Errors
To resolve 401 errors, start by checking the syntax of your headers. As Dilon from Adalo's community explains:
For the authorization header value, you need to enter Bearer<space>api_key.
Make sure there's exactly one space after "Bearer." If you're using OAuth, disconnect and reconnect the app to refresh expired tokens. For instance, Google OAuth refresh tokens expire after six months of inactivity.
To fix 403 errors, begin by confirming your plan level in Adalo's dashboard to ensure API access is enabled. Then, review your Collection Permissions to verify that the API has the rights needed for the requested action. If you're writing data, double-check that the fields are editable. Also, ensure you’re using https:// endpoints to avoid unnecessary 403 errors.
| Error Code | What It Means | Common Cause in Adalo | How to Fix |
|---|---|---|---|
| 401 Unauthorized | Server doesn't recognize your identity | Missing "Bearer" prefix; expired API key; whitespace in key | Check header formatting; regenerate and re-enter API key |
| 403 Forbidden | Valid identity but insufficient permissions | Wrong plan level; Collection Permissions restricted; monthly actions exhausted | Upgrade plan; adjust database permissions; check usage dashboard |
Next, we'll dive into common 404 errors encountered in no-code integrations.
404 Not Found Errors
A 404 Not Found error occurs when the API server cannot locate the resource you're requesting. Unlike authentication errors that block access, a 404 indicates that the endpoint you're trying to reach simply doesn't exist. In no-code platforms, these errors often stem from issues like mismatched endpoint paths, using the wrong protocol, or referencing outdated API versions.
Why 404 Errors Happen in No-Code Apps
One of the most common reasons for 404 errors is incorrect endpoint construction. For example, Adalo's External Collections automatically generate default URLs based on your Base URL. However, as the documentation explains:
The URL is also something that we default for you, based on your Base URL. However, every API is different, so you may need to change the default URLs.
This means the platform's auto-generated URL might not match the exact structure your API requires. If your API expects /api/v2/users but Adalo defaults to /users, you'll encounter a 404.
Another common cause is using HTTP instead of HTTPS. Many modern APIs only accept secure connections. Spencer Nguyen from DreamFactory highlights this issue:
An API without an HTTPS endpoint can cause a cascade of errors later... 404 Not Found: This error can indicate that a server does not have an HTTP endpoint and that your API request can't be processed.
404 errors also occur when resource IDs are invalid or missing. For instance, if you're using Magic Text to pass a record ID in a "Get One" request, but the ID was deleted or doesn't exist in the external database, the server will return a 404. Similarly, referencing deprecated API versions can lead to this error. If the documentation you're following uses an outdated endpoint path, the server won't recognize it. These problems make data retrieval impossible unless endpoints are configured correctly.
How to Fix 404 Errors
Resolving 404 errors requires careful troubleshooting. Start by manually verifying each endpoint against the latest API documentation. Ensure that the path structure matches exactly what the API requires and confirm you're using HTTPS instead of HTTP. Don’t rely solely on Adalo's default URLs - double-check every action (Get All, Get One, Create, Update, Delete) to ensure accuracy.
Testing the API externally with tools like Postman can help pinpoint whether the issue lies in the URL or your no-code configuration. Creating a simple test app to isolate the API call can also be helpful.
If you're fetching a single record, make sure the ID you're passing is valid and exists in the source database. Check that the ID format aligns with what the API expects. Note that Adalo might not support certain ID formats, like text-based UUIDs or IDs with special characters, under specific configurations, which could result in unexpected 404s. Lastly, review your Results Key settings. If the API organizes its data under a specific key (like Airtable's "records" key), ensure this is properly configured so Adalo can locate the data.
sbb-itb-d4116c7
Timeouts, Rate Limiting, and 5xx Server Errors
What Are Timeouts and Rate Limits
When it comes to maintaining smooth API integrations, understanding timeouts and rate limits is just as important as handling common errors like 400, 401, 403, and 404.
A timeout error happens when an API request takes too long to process, causing the connection to expire before a response is received. This often occurs with large payloads, complex data relationships, or heavy backend processing. On the other hand, rate limiting leads to a 429 "Too Many Requests" error when you exceed the number of requests allowed within a certain time frame. For instance, Adalo enforces a strict rate limit of 5 requests per second. If your app tries to load multiple External Collections on a single screen, you might hit this limit quickly.
Next, we’ll explore how to manage these challenges effectively.
How to Handle 5xx Server Errors
5xx errors point to server-side issues, meaning the problem lies with the API's backend rather than your app. For example, a 503 Service Unavailable error typically signals that the API's infrastructure is overloaded or experiencing temporary issues. While you can’t directly fix these server problems, you can design your app to respond more gracefully.
One approach is to implement retry logic with exponential backoff. Start with short delays (e.g., 1 second), then progressively increase the wait time (e.g., 2, 4 seconds). For 429 errors, check if the API response includes a Retry-After header, which specifies when you can safely send another request. Adalo’s developer documentation emphasizes the importance of user-friendly error handling:
Your component should be able to gracefully handle the case where an API is not available, providing a message to the user.
Testing a simplified version of your app can also help identify whether the issue stems from server limitations or something within your app’s design.
Once you’ve addressed immediate server errors, focus on strategies to reduce the likelihood of encountering them again.
How to Prevent Recurring Timeout and Server Issues
To minimize timeouts and server errors, start by optimizing your API calls. Break down complex screens into smaller, more manageable parts, batch requests whenever possible, and use caching to reduce redundant calls. Avoid overloading screens with too many relationships or custom formulas, as these can increase processing demands.
If polling triggers are causing frequent rate limit issues, consider switching to a webhook-based architecture. Webhooks can handle more traffic and are less likely to trigger 429 errors. Additionally, monitor your App Actions Dashboard to ensure you don’t exceed your action quota. Running out of actions can cause API requests to fail, sometimes returning a 403 error instead of a clearer message.
As Rollout.com puts it:
Implement retry logic and respect those rate limits – it's just good API citizenship.
Using Adalo's AnyData API Generator for Troubleshooting
How AnyData Simplifies API Integration
Adalo's External Collections feature, commonly referred to as AnyData, doubles as a troubleshooting powerhouse for external API connections. It’s designed to identify and address issues before they disrupt your app.
To get started, you’ll configure five key endpoint actions: Get All Records, Get One Record, Create, Update, and Delete. This setup helps pinpoint where problems occur. For instance, if "Get All" works but "Create" fails, you can zero in on the POST request configuration instead of wasting time questioning your authentication setup. This structured approach lays the groundwork for more advanced debugging techniques.
The "Test Your Connection" tool acts as a built-in debugger. When a connection error occurs, Adalo provides the exact error message from the external API - be it a 404 (incorrect URL), 400 (bad request), or 401 (authentication issue). This real-time feedback eliminates guesswork, enabling you to address problems during setup rather than after deployment.
For older systems without modern APIs, Adalo’s collaboration with DreamFactory offers a practical solution by generating REST API endpoints. In one example, Adalo successfully integrated with a MySQL "Employees" database containing around 4 million interconnected records. By using DreamFactory as an intermediary and setting the "Results Key" to resource, the team transformed a massive legacy dataset into a mobile-friendly directory. This method supports over 20 database types, including SQL Server and Snowflake.
For APIs like Airtable, which nest data under a top-level key (e.g., "records"), you’ll need to specify this key in the "Results Key" field during setup.
How to Debug API Errors with AnyData
Adalo’s debugging tools take the hassle out of resolving API errors, ensuring smoother integration.
If you’re dealing with authentication errors, start by manually setting Authorization parameters. For example, use Name: 'Authorization' and Value: 'Bearer [API Key]'. Additionally, adjust the HTTP method if needed - switching to PATCH, for instance, can resolve 401/403 errors.
When your connection works but no data appears in your lists, the problem often lies with Results Keys or Unique IDs. Each object in a JSON array must have a unique identifier. Without this, Adalo might fail to display records properly or repeatedly show the same item.
To ensure your JSON is error-free, use a validator like JSONLint before connecting it to Adalo. As Adalo’s documentation highlights:
If you're not sure your JSON is correct, paste it into a free validator like https://jsonlint.com. If it says valid, Adalo will usually be able to read it.
For more complex integrations, consider creating a simplified test app that focuses solely on the problematic API. This isolates the issue from other app logic, making it easier to identify the root cause. Also, confirm that you’re on a Professional, Team, or Business plan, as External Collections aren’t available on lower-tier plans. Attempting to use this feature on an unsupported plan can lead to 403 errors.
These strategies make troubleshooting API connections more manageable, ensuring your integrations run smoothly and effectively.
Conclusion
Grasping the root causes of errors like 400 Bad Request, 401/403 Authentication, 404 Not Found, and Timeout/5xx Server Errors is key to keeping your app running smoothly. These problems often arise from issues like missing headers, incorrect endpoints, or improper input validation. In fact, up to 70% of breaches at the application layer can be traced back to weak validation or authentication measures. By addressing these vulnerabilities, you can implement precise fixes and safeguard your app’s reliability.
Strong backend security is non-negotiable. While platform security provides a baseline, it doesn’t cover application-specific needs. Developers must prioritize server-side validation, enforce role-based access control, and implement robust authentication protocols such as OAuth2 or JWT. Relying only on frontend checks - even in no-code platforms - is a risky move. Backend permissions are essential to prevent unauthorized access and ensure a secure environment.
Tools like Adalo's AnyData API Generator simplify the debugging process by offering real-time error feedback, automatic property detection, and built-in troubleshooting features. For older systems lacking modern APIs, solutions like DreamFactory can generate REST endpoints, converting large datasets into formats optimized for mobile apps. This strategy not only accelerates debugging - cutting resolution time from days to hours - but also reduces development costs when compared to building custom integrations.
To avoid recurring issues, focus on preventative measures. Implement rate limiting, use HTTP status codes correctly, and verify JSON responses with tools like JSONLint. Make sure your app provides clear error messages when APIs are unavailable. For example, testing individual endpoint actions - if "Get All" works but "Create" doesn’t - can quickly pinpoint issues in your POST configuration. These proactive steps ensure smoother debugging and a more resilient app.
FAQs
How can I avoid common API errors in my no-code app?
When working with APIs in your no-code app, accuracy is key. Start by confirming that your API configurations are correct - this includes endpoint URLs, authentication credentials, and request parameters. All of these should align perfectly with the API's documentation.
Next, make sure your JSON data is structured exactly as required. Testing changes step by step can help you catch mistakes early before they snowball into bigger problems. Keep an eye on error codes and messages, too - they often point directly to what needs fixing. These proactive measures can save you headaches and keep your app running smoothly.
What are the best ways to troubleshoot API errors in no-code apps?
To troubleshoot API errors in no-code apps effectively, start by reviewing the error code documentation. This step helps you identify common issues and their potential causes, allowing you to take focused action. Once you have a basic understanding, systematically investigate the problem by analyzing your app’s workflows. Test one change at a time, and ask specific questions about how the system is behaving to narrow down the root cause.
Having a solid grasp of JSON data is equally important, as it’s a key format for API communication. Understanding JSON objects and their key-value pairs can make diagnosing data-related issues much easier. For deeper troubleshooting, leverage tools like API testing platforms. These allow you to manually send requests, examine responses, and spot errors or misconfigurations.
Don’t forget to consult your platform’s integration guides and documentation. They often outline setup standards and best practices, ensuring your configurations align with the platform’s requirements. By combining these methods, you’ll be better equipped to resolve API errors and keep your app functioning seamlessly.
How can I correctly set up my API credentials in Adalo?
To get your API credentials set up in Adalo, start by creating an API key. Head over to your app's Settings, navigate to App Access, and click on Generate Key. Once the key is generated, copy it and include it in your request headers as 'Authorization': 'Bearer YOUR_API_KEY'.
Next, find your App ID. You can do this by looking at your app's URL. Specifically, copy the section of the URL that comes after https://app.adalo.com/apps/. For example, if your app URL is https://app.adalo.com/apps/b78bdfcf-48dc-4550-a474-dd52c19fc371/app-settings, your App ID would be b78bdfcf-48dc-4550-a474-dd52c19fc371.
Once you have both the API key and App ID, include the API key in the Authorization header and use the App ID in your API request URLs. This setup ensures secure and accurate communication between your app and Adalo's API.
Related Blog Posts
