Thank you very much for your feedback!
The REST schema and request format are defined via an XML configuration file,
as I described in README.md. This XML file specifies the structure of the
services, tables, fields, and also includes templating (using Freemarker) for
how SQL queries are mapped to REST requests. This approach gives users
flexibility for different REST APIs, even when formats and requirements vary.
Additionally, I’m open to considering support for OpenAPI specifications in the
future, as it could help unify and automate integration with a wide range of
REST services.
I would be glad to join the discussion and contribute; please feel free to
create a JIRA issue so we can continue there.
Best regards,
Oleg
On 2025/11/11 09:47:26 jensen wrote:
> Copilot said: Many thanks to Oleg Alekseev for proposing
>
> Many thanks to Oleg Alekseev for proposing such an excellent idea and for his
> willingness to actively contribute to the community. As far as I know, other
> users also have similar needs. I would like to discuss this with you — please
> kindly correct me if I have misunderstood anything.
>
> I understand this project converts SQL into REST APIs. May I ask what the
> standard schema or format is for the REST APIs produced by this conversion?
> From what I know, the ES adaptor and the Arrow adaptor each follow their own
> specification. I find this topic very interesting — would it be possible to
> open a JIRA issue so we can discuss it there in more detail?
>
>
>
>
>
>
>
>
>
>
> --
>
> Best regards,
>
> Zhen Chen
>
>
>
>
> 在 2025-11-11 17:11:21 ， "Oleg Alekseev" <[email protected]> 写道：
> >
> >
> >
> >Hello Apache Calcite community,
> >
> >My name is Oleg Alekseev, and I have developed a new adapter called
> >CalciteRestAPIAdapter designed to retrieve data from REST services using
> >standard SQL syntax. This adapter leverages the Apache Calcite framework,
> >enabling access to REST APIs through JDBC by configuring service schemas and
> >tables via XML files.
> >
> >The adapter is publicly available on GitHub:
> > https://github.com/oalekseev/CalciteRestAPIAdapter
> >
> >I would like to propose this adapter as a contribution to the Apache Calcite
> >project to make it accessible and beneficial to the wider community.
> >
> >Please let me know the appropriate process and any guidelines I should
> >follow to move forward with submitting this contribution.
> >
> >Thank you for your time and consideration.
> >
> >Best regards,
> >Oleg Alekseev
> >
> >
>
>Вторник, 11 ноября 2025, 13:34 +03:00 от Oleg Alekseev < [email protected] >:
>
>Hi David,
>Thank you for your question.
>In my project, the adapter supports passing a JWT token as a parameter in the
>JDBC connection string, which is then included in the header of each REST
>request (e.g., as Authorization: Bearer ...). This enables integration with
>authentication systems relying on JWT and OAuth2/OIDC.
>Additionally, I will add a usage example for JWT authentication to the
>README.md for clarity.
>A few details about the motivation and architecture:
>My main project is an ETL engine that leverages SQL-based transformations.
>When the need arose to integrate data from REST sources, we decided to use the
>Calcite Framework and develop a custom adapter (since, unfortunately, there
>wasn’t a suitable REST adapter in the official list:
>https://calcite.apache.org/docs/adapter.html ).
>Another challenge was the unpredictable nature of REST services and their
>request formats. To address this, we utilize Apache Freemarker as a template
>engine for forming the actual REST request. This means that the application
>does not have to be rebuilt or redeployed when supporting a new REST source;
>instead, a user only needs to provide an XML configuration file for the new
>REST service, defining the request template using Freemarker.
>Practically, the received filters and projects parameters in the
>Enumerable<@Nullable Object[]> scan(DataContext root, List filters, int
>@Nullable[] projects)
>method of the org.apache.calcite.schema.ProjectableFilterableTable interface
>are passed into the Freemarker context. They can then be used to construct the
>REST request in any way that fits the supported features of the target REST
>API.
>
>Best regards,
>Oleg
>On 2025/11/11 09:37:41 David Radley wrote:
>> Hi,
>> It looks interesting. What is the security story around this? e.g.
>> certificates / OIDC etc,
>> Kind regards, David.
>>
>> From: Oleg Alekseev < [email protected] >
>> Date: Tuesday, 11 November 2025 at 09:13
>> To: [email protected] < [email protected] >
>> Subject: [EXTERNAL] Proposal to contribute CalciteRestAPIAdapter for
>> community use
>>
>>
>>
>>
>> Hello Apache Calcite community,
>>
>> My name is Oleg Alekseev, and I have developed a new adapter called
>> CalciteRestAPIAdapter designed to retrieve data from REST services using
>> standard SQL syntax. This adapter leverages the Apache Calcite framework,
>> enabling access to REST APIs through JDBC by configuring service schemas and
>> tables via XML files.
>>
>> The adapter is publicly available on GitHub:
>> https://github.com/oalekseev/CalciteRestAPIAdapter
>>
>> I would like to propose this adapter as a contribution to the Apache Calcite
>> project to make it accessible and beneficial to the wider community.
>>
>> Please let me know the appropriate process and any guidelines I should
>> follow to move forward with submitting this contribution.
>>
>> Thank you for your time and consideration.
>>
>> Best regards,
>> Oleg Alekseev
>>
>>
>> Unless otherwise stated above:
>>
>> IBM United Kingdom Limited
>> Registered in England and Wales with number 741598
>> Registered office: Building C, IBM Hursley Office, Hursley Park Road,
>> Winchester, Hampshire SO21 2JN
>>
--
Олег Алексеев
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