# Traces on Claude

**URL:** https://forum.langchain.com/t/traces-on-claude/4275
**Category:** Observability & Evals
**Created:** [August 2, 2026, 6:35am UTC](https://forum.langchain.com/t/traces-on-claude/4275 "2026-08-02T06:35:59Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Gregradzio](https://avatars.discourse-cdn.com/v4/letter/g/5fc32e/32.png) [@Gregradzio](https://forum.langchain.com/u/Gregradzio)
#### Post date: [August 2, 2026, 6:35am UTC](https://forum.langchain.com/t/traces-on-claude/4275/1 "2026-08-02T06:35:59Z")

</div>

I know how to make traces work with Langsmith platform when I use the langchain or deepagents but sometimes I am using things like anthropic sdk (claude -p ) or codex cli directly in my harness and I wonder is there a way to use session logs left from these tools and upload as traces to langsmith? i know i could probably use the tracable function but will I dont think it will do exactly what I want…

so long story short:

if somewhere in my harness I run: `claude -p ` with the task and that produces session log for me - can I have this session in langsmith exactly the way how i would use langchain or deepagents?

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<div class="post-metadata">

### Author: ![pawel-twardziak](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/pawel-twardziak/32/960_2.png) [@pawel-twardziak](https://forum.langchain.com/u/pawel-twardziak)
#### Post date: [August 2, 2026, 8:59pm UTC](https://forum.langchain.com/t/traces-on-claude/4275/2 "2026-08-02T20:59:54Z")

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hi @Gregradzio

have you tried [Trace Claude Code applications - Docs by LangChain](https://docs.langchain.com/langsmith/trace-claude-code) ?

```auto
/plugin marketplace add langchain-ai/langsmith-claude-code-plugins
/plugin install langsmith-tracing@langsmith-claude-code-plugins
/reload-plugins

```

then

```auto
export TRACE_TO_LANGSMITH="true"
export CC_LANGSMITH_API_KEY="<your LangSmith API key>"
export CC_LANGSMITH_PROJECT="claude-code"

claude -p "your task"

```

You can put the same values in `.claude/settings.local.json` if project-level configuration is more convenient:

```json
{
  "env": {
    "TRACE_TO_LANGSMITH": "true",
    "CC_LANGSMITH_API_KEY": "<your LangSmith API key>",
    "CC_LANGSMITH_PROJECT": "claude-code"
  }
}

```

When `claude -p` is part of a larger traced harness (python):

```py
import os
import subprocess

from langsmith import get_current_run_tree, traceable

@traceable(name="run_claude")
def run_claude(prompt: str) -> str:
    parent = get_current_run_tree()
    result = subprocess.run(
        ["claude", "-p", prompt],
        check=True,
        capture_output=True,
        text=True,
        env={
            **os.environ,
            "TRACE_TO_LANGSMITH": "true",
            "CC_LANGSMITH_API_KEY": os.environ["LANGSMITH_API_KEY"],
            "CC_LANGSMITH_PROJECT": "claude-code",
            "CC_LANGSMITH_PARENT_DOTTED_ORDER": parent.dotted_order,
        },
    )
    return result.stdout

```

or JS

```js
import { spawn } from "node:child_process";
import { traceable, getCurrentRunTree } from "langsmith/traceable";

const runClaude = traceable(
  async (prompt: string): Promise<string> => {
    const parent = getCurrentRunTree();

    return new Promise((resolve, reject) => {
      const child = spawn("claude", ["-p", prompt], {
        env: {
          ...process.env,
          TRACE_TO_LANGSMITH: "true",
          CC_LANGSMITH_API_KEY: process.env.LANGSMITH_API_KEY!,
          CC_LANGSMITH_PROJECT: "claude-code",
          CC_LANGSMITH_PARENT_DOTTED_ORDER: parent.dotted_order,
        },
      });

      let stdout = "";
      let stderr = "";

      child.stdout.on("data", chunk => (stdout += chunk));
      child.stderr.on("data", chunk => (stderr += chunk));

      child.on("error", reject);
      child.on("close", code => {
        if (code === 0) resolve(stdout);
        else reject(new Error(`Claude exited with code ${code}: ${stderr}`));
      });
    });
  },
  { name: "run_claude" },
);

await runClaude("Your task");

```

---

<div class="post-metadata">

### Author: ![Gregradzio](https://avatars.discourse-cdn.com/v4/letter/g/5fc32e/32.png) [@Gregradzio](https://forum.langchain.com/u/Gregradzio)
#### Post date: [August 3, 2026, 4:52am UTC](https://forum.langchain.com/t/traces-on-claude/4275/3 "2026-08-03T04:52:16Z")

</div>

actually yes - i had to do tiny tweaks for my eval harness but it worked, thanks