Logger doesn't accept Semantic Conventions for Generative AI

[btomaj]

What happened?

Context

The Semantic Conventions for Generative AI in 1.37.0 specify that for gen_ai.input.messages and gen_ai.output.messages, "When the attribute is recorded on events, it MUST be recorded in structured form", but Logger doesn't accept the respective JSON schemas of input and output messages as an event attribute.

Steps to Reproduce

Can easily reproduce using the tests in the instrumentation-openai package here: open-telemetry/opentelemetry-js-contrib#3194

    this.logger.emit({
      timestamp: Date.now(),
      context: ctx,
      severityNumber: SeverityNumber.INFO,
      eventName: EVENT_GEN_AI_CLIENT_INFERENCE_OPERATION_DETAILS,
      attributes: {
        [ATTR_GEN_AI_PROVIDER_NAME]: GEN_AI_PROVIDER_NAME_VALUE_OPENAI,
        [ATTR_GEN_AI_INPUT_MESSAGES]: [
          {
            "key": "value"
          }
        ],
      },
    });

Expected Result

The ATTR_GEN_AI_INPUT_MESSAGES attribute is logged.

Actual Result

The ATTR_GEN_AI_INPUT_MESSAGES attribute throws error.

Additional Details

It appears that Logger only accepts an array of primitives as an attribute.

OpenTelemetry Setup Code

package.json

Relevant log output

Operating System and Version

No response

Runtime and Version

No response

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[trentm]

My guess is this needs #5765 or similar, but I will take a closer look at this later.