Could not parse request body into json: Unexpected character (\'-\' (code 45)) AWS Lambda + API + Postman

I just got stuck with this today.

your mapping template is:

{ "name": "$input.params('name')" }

AWS uses AWS Velocity templates, which; even though looks like JSON, is different.

if you use

{ "name": $input.params('name') } // notice no quotes

for the mapping template right at the integration request step, then it should work as expected.

Read the error message very carefully, it actually tells you the problem. For example, I got

Could not parse request body into json: Unexpected character (\'\"\' (code 34)): was expecting comma to separate Object entries

So the problem is that I'm missing a comma. I check my Lambda's Integration Request - Body Mapping Template:

{"age" : $input.json('$.persondata.age'),"income" : $input.json('$.persondata.income')"height" : $input.json('$.persondata.height')}

Can you spot the problem? I am missing a comma after the income line.

Here is another example.

Could not parse request body into json: Unexpected character (\'}\' (code 125)): expected a value

When I look at the Integration Request - Body Mapping Template:

#set($inputRoot = $input.path('$')){  "age" : $inputRoot.age,  "height" : $inputRoot.height,  "income" : $inputRootincome}

Can you spot the problem? I am missing a dot in $inputRootincome.

Error Message :

Could not parse request body into json: Could not parse payload into json: Unrecognized token \' \': was expecting (\'true\', \'false\' or \'null\')

Cause of the error : When string values inside the json are not assigned using double quotations in the aws mapping template the error occurs.

Solution : (Please Note : This example is for application/json type request template)

Actually the solution for the problem is, if you are using a value of type string in json then its value should be assigned inside a ("" - double quotation marks) in the mapping template.

The below shown example has the following attributes :

customerId - string (Please note : this value comes from a query parameter)customerName - stringcustomerAge - integerisPermanentEmployee - booleancustomerAddress - string (Please note this is an optional parameter)

And the mapping template should be defined like the example shown below

Refer the example below :

#set($inputRoot = $input.path('$')){  "CustomerId": "$input.params('customerId')",  "CustomerName": "$inputRoot.customerName",  "CustomerAge": $inputRoot.customerAge,  "IsPermanentEmployee": $inputRoot.isPermanentEmployee  "CustomerAddress ": #if($inputRoot.customerAddress == "") "" #elseif($inputRoot.customerAddress != "") "$inputRoot.customerAddress" #end}

If you note the above mapping template, I would have given string values inside double quotation marks("") which will solve the error

Also this example contains how to handle optional parameters in aws mapping templates using #if#else statements.