[BUG]: Incompatible with grape 3.1.x

[pkopac]

Tracer Version(s)

2.28.0

Ruby Version(s)

ruby 3.4.8 (2025-12-17 revision 995b59f666) +YJIT +PRISM [x86_64-linux]

Relevent Library and Version(s)

grape 3.1.1

Bug Report

There are breaking changes in grape's recent minor version, which is not DataDog's fault, but the library needs to be adapted.

AI explanation:

Grape 3.1.0 removed the public attr_reader :base from Grape::API::Instance (in https://github.com/ruby-grape/grape/pull/2633). The Datadog gem's Grape integration calls
  api.base.to_s in its api_view method:

  # datadog/tracing/contrib/grape/endpoint.rb
  def api_view(api)
    if defined?(::Grape::API::Instance) && api <= ::Grape::API::Instance
      api.base.to_s   # ← this method no longer exists in Grape 3.1.x
    else
      api.to_s
    end
  end

  Datadog 2.28.0 hasn't been updated to handle this breaking change in Grape 3.1.x.

https://github.com/DataDog/dd-trace-rb/blob/master/lib/datadog/tracing/contrib/grape/endpoint.rb#L260

Reproduction Code

No response

Configuration Block

No response

Error Logs

[datadog] (/usr/local/bundle/gems/datadog-2.28.0/lib/datadog/tracing/contrib/grape/endpoint.rb:80:in 'Datadog::Tracing::Contrib::Grape::Endpoint.endpoint_start_process') undefined method 'base' for class #Class:0x00007fdf16a4d7b8

Operating System

No response

How does Datadog help you?

No response

[lenon]

Same issue here with Ruby 4.0.1, grape 3.1.1 and datadog 2.28.0.

E, [2026-02-25T21:45:45.263756 #46] ERROR -- datadog: [datadog] (/usr/local/bundle/gems/datadog-2.28.0/lib/datadog/tracing/contrib/grape/endpoint.rb:80:in 'Datadog::Tracing::Contrib::Grape::Endpoint.endpoint_start_process') undefined method 'base' for class API::KubernetesMetrics

[ivoanjo]

#5364 + #5414 will fix this and should land soon!