How to pass a path parameter in API gateway to invoke lambda function?

Question

I need to pass a path param in the API.

By using the mapping template, I am able to pass query params and use them in the function.

Mapping template:

{ "Id": "$input.params('Id')" //this works fine after passing params as <url>?param=vale }

With reference to this I created the mapping template as following-

{ "Id": "$input.params().querystring.get('Id')" // requirement is to be able to use <url>/value }

I tried using 'Method request template' under genrate template, but it didn't work either.

When I invoke the URL urlname.execute-api.us-east-2.amazonaws.com/stag/functionname, it gives the value as undefined.

This is how I'm using the param:

class Lambda { static run(event, context, callback) { callback(null, 'Id '+ event.Id); } } module.exports = Lambda;

Also, please tell me how to use those params in code. Be kind :)

@AssaelAzran I see answers related to that. Is it absolutely mandatory? — Harshita
– Harshita, Commented Dec 4, 2019 at 17:37
No. i just asked it to get more information. so i guess your api is a non proxy one. am i right? — Assael Azran
– Assael Azran, Commented Dec 4, 2019 at 17:42

Assael Azran · Accepted Answer · 2019-12-05 07:32:20Z

2

In order to be able to use <url>/value and get value from event follow this (Tested):

Configure your API gateway resource

Under /api2/{id} - GET - Integration Request configure your Mapping Templates

Execute request https://123456.execute-api.my-region.amazonaws.com/stage/api2/123

Lambda

console.log(event.id) callback(null, { id:event.id });

CloudWatch

Hope this helps

answered Dec 4, 2019 at 21:35

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3 Comments

how do we configure {id} under api?

just create a resource under api and in the path section insert {id}

added a snapshot to my answer. if you are using a non proxy api don't forget to configure status code in your method response.