Technical Analysis: Resolving "Not a Valid Key=Value Pair (Missing Equal-Sign) in Authorization Header" Error in API Gateway POST Requests

Problem Background and Error Description

When making POST requests to AWS API Gateway, developers often encounter the error message: "{message:'{My Token}' not a valid key=value pair (missing equal-sign) in Authorization header: 'Bearer {My Token}'.}" This error indicates an invalid key-value pair format in the Authorization header, typically caused by URL parsing or request configuration issues. In the case study, the developer uses Python code to send requests with headers including Authorization and Content-type, but API Gateway returns this error even though token validation passes.

Error Cause Analysis

The core cause of the error lies in how API Gateway processes request URLs and headers. Based on Answer 2, the main issues include:

• URL Parsing Issues: When using {proxy+} resources, incorrect URL parsing can lead to the Authorization header being misjudged as invalid. Answer 1 adds that erroneous URL resolution is a common cause, even without proxies.
• Incorrect Use of Python Requests Library: In the code, passing JSON data via the data parameter without converting it to a string. In Python's requests.post method, the data parameter only accepts string types; passing a dictionary directly causes format errors, affecting the entire request header.

In the case, when the URL is changed to include an arbitrary string, the error disappears, but the S3 bucket does not receive the file, indicating that URL configuration still needs adjustment.

Solutions

Based on Answer 2, resolving this error requires two approaches:

1. Adjust API Gateway Resource Configuration: Avoid unnecessary {proxy+} resources and set methods from the root resource. This simplifies URL parsing and reduces errors. For example, change the resource path from /MyStage/{proxy+} to /MyStage to ensure requests directly target the destination.
2. Correct Python Code: Properly use the requests.post method. There are two ways:
   • Use the json parameter: response = requests.post(url, headers=headers, json=my_json), where my_json is a dictionary, and the library handles JSON serialization automatically.
   • Use the data parameter with manual serialization: response = requests.post(url, headers=headers, data=json.dumps(my_json)), requiring import of the json module.

Corrected code example:

import requests
import json

url = "https://my-api-gateway.amazonaws.com/MyStage"
token = "your_token_here"
headers = {
    "Authorization": "Bearer " + token,
    "Content-type": "application/json"
}
my_json = {"id": "0678a93d-ee8c-4db5-a831-1e311be4f04b", "test": "12345"}
response = requests.post(url, headers=headers, json=my_json)
print(response.text)

Additional Recommendations and Best Practices

Incorporating insights from Answer 1 and other experiences, the following suggestions are provided:

• Verify URL Correctness: Ensure the API Gateway URL is complete and free of extra paths. Use tools like Postman for testing to avoid encoding errors.
• Check Token Format: Although token validation passes in the case, ensure the Authorization header format is "Bearer token" without extra spaces or special characters.
• Monitoring and Logging: Enable logging in API Gateway to analyze request details and quickly locate issues.
• Testing Environment: Thoroughly test different scenarios during development, including error handling.

Conclusion

By adjusting API Gateway resource configuration and correcting Python code, the Authorization header invalid key-value pair error can be effectively resolved. Key points include understanding URL parsing mechanisms and proper use of HTTP libraries. Based on a real-world case, this article offers detailed analysis and solutions to help developers improve API call reliability. It is recommended to follow best practices to minimize the occurrence of similar errors.