feat: integrate OpenTelemetry

[tianhuil]

Hi @thdxr, @adamdotdevin, and @rekram1-node

I love opencode. Trying to run it with open telemetry and wanted to add back some code to the project. If you generaly like this commit, I can work on resolving the merge conflict (just imports, nothing big).

Summary

• Integrate OpenTelemetry for enhanced tracing and monitoring capabilities
• Add type annotations to execute and toModelOutput methods in SessionPrompt

Changes

• Added OpenTelemetry dependencies for comprehensive observability
• Fixed type annotations in SessionPrompt methods for better type safety
• Updated package lock file with new dependencies

[rekram1-node]

I think opencode already emits telemetry spans if you set:

experimental_opentelemetry to true in your opencode.json

[tianhuil]

Thanks for the quick response @rekram1-node.

I set the following and it didn't work:

//.opencode/opencode.jsonc
{
  "$schema": "https://opencode.ai/config.json",
  "experimental": {
    "openTelemetry": true
  },
}

I had to modify the repo to get it to emit open telemetry.

[franroa]

Would be nice to have something like this https://www.reddit.com/r/ClaudeCode/comments/1pjon1r/til_that_claude_code_has_opentelemetry_metrics/

[didier-durand]

Hi,
Just setting:

  "$schema": "https://opencode.ai/config.json",
  "experimental": {
    "openTelemetry": true
  },
}

doesn't work for me either.

Minimally, additional packages from OpenTelemetry JavaScript SDK need to be added

[pai4451]

@rekram1-node @tianhuil

I love this feature, is it possible to add open telemetry support and contains productivity metrics (such as acceptance rate or lines of code) like claude code?

https://code.claude.com/docs/en/monitoring-usage#lines-of-code-counter

[didier-durand]

Working on a PR to fully enable OTEL for opencode in a container image. Hope to be able to share it soon

[Phantal]

If it helps. I submitted a merge request to add otel support awhile back, but it got very little traction:

#2735

[didier-durand]

@Phantal : Yes, I saw your PR. On my side, I am trying to obtain full leverage of AI SDK Otel implementation by Vercel. I want to add much less code than your PR and just minimally change the current Otel setup.

[fiktor]

Let me document how OTel in OpenCode works without this PR.

I tested the current OpenCode (opencode-ai@1.1.51, opencode-ai@1.1.53, without this PR), and the spans are emitted/exported subject to the following pre-requisites:

1. a modern version of @opentelemetry is installed in the opencode bun environment. I installed "@opentelemetry/sdk-node" version "0.200". There are two ways to accomplish this
   • global: add the package name to ~/.config/opencode/packages.json and run bun install inside ~/.config/opencode.
   • should be also possible to do it when using per-project config / plugins but I didn't test it.
   • This step can be omitted if one uses npm-installed package (by specifying it in opencode.json) as opposed to local module (by putting it in plugins/ directory) if @opentelemetry/... (e.g. @opentelemetry/sdk-node) is a dependency of that plugin's npm package: in that case opencode will install the dependency automatically before loading the plugin.
2. experimental.openTelemetry = true is set in opencode.json.
3. something (e.g. a plugin) should initialize and start NodeSDK. E.g. I implemented a plugin with the following key code in the main plugin function, and it worked:

  try {
    const processor = new JsonlSpanProcessor(stream);
    const sdk_node_module = await import("@opentelemetry/sdk-node");
    sdk = new sdk_node_module.NodeSDK({ spanProcessors: [processor] });
    sdk!.start()
  } catch (e) {
    ...
  }

Here:

• the JsonlSpanProcessor I implemented just dumps spans to a file,
• import is intentionally inside the plugin function
  • With standard import statement at the top of the file, if opentelemetry is missing, OpenCode freezes due to failure to load the plugin, which is hard to debug.
  • Inside the function, I opened the log already and can log the failure to import.
• the next to lines (sdk= and sdk.start) are essentially from the example in add experimental.open_telemetry config option to enable OTEL spans #4978 (comment)

4. Finally, the OTel processor (like JsonlSpanProcessor in my example above) should do something to make the spans exported and visible to external observers (e.g. write to a file in my example, or, e.g., export via http).

There are 3 types (i.e. 3 values of span.name) logged: ai.streamText, ai.toolCall, ai.streamText.doStream. The spans are not coming directly from OpenCode but from Vercel AI SDK opencode is using. They contain full text of prompts. Here is one of 3 lines where span is created: https://github.com/vercel/ai/blob/c36a873ce00892a4c587c2e9492220b392aefd09/packages/ai/src/generate-text/stream-text.ts#L1142