AWS Appsync $ctx vs $context in resolvers

Question

I understand that context is what ever name you define in your Lambda functions but when it comes to Appsync resolvers I'm a bit confused. I've seen both $ctx and $context being used in AppSync resolvers including in AWS docs. Some of AWS's own code generation tools like AWS Amplify CLI create resolvers that use both in the same code! I can't find anything in the docs explaining this. What's going on here?

I'm in the process of scrubbing our docs and replacing `$context` with `$ctx` for consistency. I'll add a note to the [Resolver Mapping page](https://docs.aws.amazon.com/appsync/latest/devguide/resolver-context-reference.html) explaining that `$ctx` is an alias. Sorry for the confusion. — Rohan Deshpande, Mar 19 '19 at 15:53

score 27 · Accepted Answer · answered Mar 19 '19 at 15:51

27

(AWS AppSync dev here)

$ctx and $context in AWS AppSync refer to the same Resolver Context. We added $ctx as an alias for $context to reduce the number of characters users have to type ($ctx is 50% shorter than $context!!)

Choosing $context or $ctx is a personal preference. I prefer $ctx when I'm authoring AWS AppSync resolvers.

answered Mar 19 '19 at 15:51

Rohan Deshpande

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thank you for the answer. Does the same apply to arguments? I've seen some place use $ctx.args... ?Any other helpful aliases? – user3376065 Mar 19 '19 at 20:48
$ctx.* and $context.* refer to the same thing. – Rohan Deshpande Mar 20 '19 at 14:59
Just a minor note, $ctx is not allowed when referencing cache keys. Caching keys need to start with $context.args, $context.arguments, $context.identity, or $context.source, otherwise AppSync fails with 400 – tratto Jul 02 '21 at 15:58
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Why not `$c`? 85% less to type. – Andrey Feb 10 '22 at 15:14

AWS Appsync $ctx vs $context in resolvers

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