Feedback-ID: i76984098:Fastmail
Message-ID: <f35c63af-037f-46c5-a99f-9bb514681cf7@aklaver.com>
Date: Sun, 16 Nov 2025 09:25:42 -0800
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Overriding default adapters in psycopg
To: Christophe Pettus <xof@thebuild.com>, psycopg@lists.postgresql.org
References: <FA57033D-66AE-42E9-8C5E-968CF69DB893@thebuild.com>
Content-Language: en-US
From: Adrian Klaver <adrian.klaver@aklaver.com>
In-Reply-To: <FA57033D-66AE-42E9-8C5E-968CF69DB893@thebuild.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Archived-At: 
 <https://www.postgresql.org/message-id/f35c63af-037f-46c5-a99f-9bb514681cf7%40aklaver.com>
Precedence: bulk

On 11/16/25 08:56, Christophe Pettus wrote:
> Hi!
> 
> I am attempting to override the default adapters for JSON and JSONB in psycopg (3), but I am not quite sure how to go about it (I'm testing using orjson for serialization and deserialization).  This doesn't appear to work:
> 
>> class CyanJSONBLoader(Loader):
>>      def load(self, data):
>>          return orjson.loads(data)
>>
>> psycopg.adapters.register_loader("jsonb", CyanJSONBLoader)
>>
>> class CyanJSONBDumper(Dumper):
>>      def dump(self, obj):
>>          return orjson.dumps(obj)
>>
>> psycopg.adapters.register_dumper("jsonb", CyanJSONBDumper)
>>
> 
> The calls work, but the dump/load functions are never called.

I think you might need to use:

https://www.psycopg.org/psycopg3/docs/basic/adapt.html#adapt-json


> 
> Thanks!
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com