Trace Class

The Trace class represents a high-level operation or workflow in your LLM application. Traces capture the entire lifecycle of a request, batch job, or user interaction, and can contain multiple child spans for granular tracking.

Overview

A trace is the top-level unit of observability that represents:

A single user request to your API
A background job or workflow
A conversation turn in a chatbot
A complete RAG pipeline execution
Any end-to-end operation you want to track

Traces contain:

Metadata: name, status, timestamps, tags, attributes
Context: session ID, reference ID
Children: one or more spans representing sub-operations

Creation

Create a trace using the Monitor.logTrace() method:

const trace = monitor.logTrace({
  name: 'User Login',
  sessionId: 'session-abc-123',
  tags: ['auth', 'production'],
  attributes: { userId: 'user-456' }
});

Properties

trace

trace: CreateLogTraceRequest

The underlying trace request object that will be sent to the API. Contains all trace metadata. Structure:

{
  projectId: string;
  trace: {
    name: string;
    status: TraceStatus;
    sessionId?: string;
    referenceId: string;
    tags?: string[];
    attributes?: Record<string, LogAttributesValue>;  // LogAttributesValue = string | number | boolean
    startedAt: number;     // Unix timestamp in milliseconds
    endedAt?: number;      // Set when trace.end() is called
  }
}

traceId

traceId: string | undefined

The server-assigned trace ID, set after the trace is successfully flushed to the API.

const trace = monitor.logTrace({ name: 'Operation' });
console.log(trace.traceId); // undefined (not flushed yet)

trace.end();
await monitor.flush();

console.log(trace.traceId); // "trace_abc123xyz" (assigned by server)

Methods

logSpan()

Create a child span within this trace.

logSpan(options: LogSpanOptions): Span

Parameters

object

required

Show properties

string

required

Human-readable name for the span (e.g., “LLM Call”, “Database Query”).

SpanStatus

default:"unknown"

Initial SpanStatus: 'success' | 'failure' | 'aborted' | 'cancelled' | 'unknown'

string

Custom reference ID. Auto-generated UUID if not provided.

string

ID of the prompt used in this span (for LLM calls).

string | null

ID of the deployment used in this span.

boolean

Whether to run evaluators on this span after completion.

string[]

Tags for categorization (e.g., ['llm', 'openai']).

Record<string, LogAttributesValue>

Additional metadata (e.g., { model: 'gpt-4o', tokens: 1500 }). LogAttributesValue = string | number | boolean

LogSpanContent

LogSpanContent (input/output data). Defaults to monitor.defaultContent.

Returns

Span

A new Span instance. See Span Class for details.

Examples

const trace = monitor.logTrace({ name: 'API Request' });

const span = trace.logSpan({
  name: 'Process Data'
});

// Do work...
await processData();

span.update({ status: 'success' });
span.end();
trace.end();

const trace = monitor.logTrace({
  name: 'Chat Completion',
  sessionId: userId
});

const llmSpan = trace.logSpan({
  name: 'OpenAI GPT-4',
  promptId: deployment.promptId,
  deploymentId: deployment.id,
  runEvaluation: true,
  tags: ['llm', 'openai', 'gpt-4o'],
  attributes: {
    model: 'gpt-4o',
    temperature: 0.7
  }
});

const response = await openai.chat.completions.create({ /* ... */ });

llmSpan.update({
  status: 'success',
  content: {
    type: 'Model',
    provider: 'openai',
    model: 'gpt-4o',
    input: JSON.stringify(messages),
    output: JSON.stringify(response.choices[0].message)
  }
});

llmSpan.end();
trace.end();

const trace = monitor.logTrace({ name: 'RAG Pipeline' });

// Parent span
const ragSpan = trace.logSpan({
  name: 'RAG Operation',
  tags: ['rag']
});

// Child spans
const embeddingSpan = ragSpan.logSpan({
  name: 'Generate Embedding',
  tags: ['embedding']
});
embeddingSpan.end();

const retrievalSpan = ragSpan.logSpan({
  name: 'Vector Search',
  tags: ['retrieval']
});
retrievalSpan.end();

const llmSpan = ragSpan.logSpan({
  name: 'Generate Answer',
  tags: ['llm']
});
llmSpan.end();

ragSpan.end();
trace.end();

update()

Update trace metadata in place.

update(updates: TraceUpdates): this

Parameters

object

required

Partial updates to apply to the trace.

Show properties

string

Update the trace name.

TraceStatus

string[]

Update tags (replaces existing tags).

Record<string, LogAttributesValue>

Update attributes (merges with existing attributes). LogAttributesValue = string | number | boolean

Returns

Returns this for method chaining.

Examples

const trace = monitor.logTrace({
  name: 'Process Order',
  status: 'pending'
});

try {
  await processOrder();
  trace.update({ status: 'success' });
} catch (error) {
  trace.update({ status: 'failure' });
}

trace.end();

const trace = monitor.logTrace({ name: 'User Request' });

// Add attribute after getting user info
const userId = await getUserId();
trace.update({
  attributes: { userId }
});

// Add more attributes
trace.update({
  attributes: { 
    processingTime: Date.now() - startTime,
    itemsProcessed: 42
  }
});

trace.end();

monitor.logTrace({ name: 'Quick Operation' })
  .update({ status: 'pending' })
  .update({ tags: ['fast', 'important'] })
  .end();

trace.update({
  name: 'Updated Name',
  status: 'success',
  tags: ['completed', 'verified'],
  attributes: {
    duration: 1234,
    outcome: 'positive'
  }
});

end()

Mark the trace as complete and ready to be flushed.

end(): string | undefined

Behavior

Sets endedAt timestamp if not already set
Marks the trace as ready in the monitor’s buffer
Recursively ends all child spans (and their descendants)
Returns the trace’s reference ID

Always call end() on your traces! Traces that are never ended will never be flushed to the API.

Returns

string | undefined

The trace’s reference ID for correlation with external systems.

Examples

const trace = monitor.logTrace({ name: 'Operation' });

// Do work...

trace.end(); // Required!

const trace = monitor.logTrace({ name: 'Critical Operation' });

try {
  await doWork();
  trace.update({ status: 'success' });
} catch (error) {
  trace.update({ status: 'failure' });
  throw error;
} finally {
  trace.end(); // Always called, even if error thrown
}

const trace = monitor.logTrace({
  name: 'Async Job',
  referenceId: `job-${jobId}`
});

// Do work...

const refId = trace.end();
console.log(`Trace completed: ${refId}`); // "job-123"

const trace = monitor.logTrace({ name: 'Parent' });

const span1 = trace.logSpan({ name: 'Child 1' });
const span2 = span1.logSpan({ name: 'Grandchild' });
const span3 = trace.logSpan({ name: 'Child 2' });

// Don't need to manually end children
trace.end(); // Automatically ends span1, span2, span3

Complete Examples

Example 1: Simple API Request

import { Adaline } from '@adaline/client';
import { Gateway } from '@adaline/gateway';
import { OpenAI } from '@adaline/openai';

const adaline = new Adaline();
const gateway = new Gateway();
const openaiProvider = new OpenAI();
const monitor = adaline.initMonitor({ projectId: 'my-api' });

async function handleChatRequest(userId: string, message: string) {
  // Create trace for this request
  const trace = monitor.logTrace({
    name: 'Chat Request',
    sessionId: userId,
    tags: ['chat', 'api'],
    attributes: {
      userId,
      messageLength: message.length
    }
  });

  try {
    // Log the LLM call
    const llmSpan = trace.logSpan({
      name: 'OpenAI Completion',
      tags: ['llm']
    });

    const model = openaiProvider.chatModel({
      modelName: 'gpt-4o',
      apiKey: process.env.OPENAI_API_KEY!
    });

    const gatewayResponse = await gateway.completeChat({
      model,
      messages: [
        { role: 'user', content: [{ modality: 'text', value: message }] }
      ]
    });

    llmSpan.update({
      status: 'success',
      content: {
        type: 'Model',
        provider: 'openai',
        model: 'gpt-4o',
        input: JSON.stringify(gatewayResponse.provider.request),
        output: JSON.stringify(gatewayResponse.provider.response)
      }
    });
    llmSpan.end();

    trace.update({ status: 'success' });
    return gatewayResponse.response.messages[0].content[0].value;

  } catch (error) {
    trace.update({
      status: 'failure',
      attributes: {
        error: error instanceof Error ? error.message : String(error)
      }
    });
    throw error;

  } finally {
    trace.end();
  }
}

Example 2: Multi-Step Workflow

async function processUserOnboarding(userId: string) {
  const trace = monitor.logTrace({
    name: 'User Onboarding',
    sessionId: userId,
    status: 'pending',
    tags: ['onboarding', 'workflow'],
    attributes: { userId }
  });

  try {
    // Step 1: Create account
    const createSpan = trace.logSpan({
      name: 'Create Account',
      tags: ['database']
    });
    await createAccount(userId);
    createSpan.update({ status: 'success' });
    createSpan.end();

    // Step 2: Send welcome email
    const emailSpan = trace.logSpan({
      name: 'Send Welcome Email',
      tags: ['email']
    });
    await sendWelcomeEmail(userId);
    emailSpan.update({ status: 'success' });
    emailSpan.end();

    // Step 3: Generate personalized content
    const llmSpan = trace.logSpan({
      name: 'Generate Welcome Message',
      tags: ['llm', 'personalization']
    });
    const welcomeMsg = await generateWelcomeMessage(userId);
    llmSpan.update({
      status: 'success',
      content: {
        type: 'Model',
        provider: 'openai',
        model: 'gpt-4o',
        input: JSON.stringify({ userId }),
        output: JSON.stringify({ message: welcomeMsg })
      }
    });
    llmSpan.end();

    trace.update({ status: 'success' });

  } catch (error) {
    trace.update({
      status: 'failure',
      attributes: { error: String(error) }
    });
    throw error;

  } finally {
    trace.end();
  }
}

Example 3: Nested Operations (RAG Pipeline)

async function answerQuestion(sessionId: string, question: string) {
  const trace = monitor.logTrace({
    name: 'RAG Question Answering',
    sessionId,
    tags: ['rag', 'qa'],
    attributes: { questionLength: question.length }
  });

  try {
    // Parent span for entire RAG operation
    const ragSpan = trace.logSpan({
      name: 'RAG Pipeline',
      tags: ['pipeline']
    });

    // Step 1: Generate embedding (child of ragSpan)
    const embedSpan = ragSpan.logSpan({
      name: 'Generate Query Embedding',
      tags: ['embedding']
    });
    const embedding = await generateEmbedding(question);
    embedSpan.update({
      status: 'success',
      content: {
        type: 'Embeddings',
        input: JSON.stringify({ query: question }),
        output: JSON.stringify({ dimensions: embedding.length })
      }
    });
    embedSpan.end();

    // Step 2: Retrieve documents (child of ragSpan)
    const retrieveSpan = ragSpan.logSpan({
      name: 'Vector Search',
      tags: ['retrieval', 'vector-db']
    });
    const docs = await retrieveDocuments(embedding);
    retrieveSpan.update({
      status: 'success',
      content: {
        type: 'Retrieval',
        input: JSON.stringify({ embedding: 'vector', topK: 5 }),
        output: JSON.stringify({ documentIds: docs.map(d => d.id) })
      },
      attributes: { documentsFound: docs.length }
    });
    retrieveSpan.end();

    // Step 3: Generate answer (child of ragSpan)
    const llmSpan = ragSpan.logSpan({
      name: 'Generate Answer',
      tags: ['llm', 'answer-generation'],
      runEvaluation: true
    });
    const answer = await generateAnswer(question, docs);
    llmSpan.update({
      status: 'success',
      content: {
        type: 'Model',
        provider: 'openai',
        model: 'gpt-4o',
        input: JSON.stringify({ question, context: docs }),
        output: JSON.stringify({ answer })
      }
    });
    llmSpan.end();

    ragSpan.update({ status: 'success' });
    ragSpan.end();

    trace.update({ status: 'success' });
    return answer;

  } catch (error) {
    trace.update({ status: 'failure' });
    throw error;

  } finally {
    trace.end();
  }
}

Example 4: Long-Running Background Job

async function processBatch(batchId: string) {
  const trace = monitor.logTrace({
    name: 'Batch Processing',
    referenceId: `batch-${batchId}`,
    status: 'pending',
    tags: ['batch', 'background'],
    attributes: {
      batchId,
      startTime: Date.now()
    }
  });

  const items = await getBatchItems(batchId);
  
  trace.update({
    attributes: { itemCount: items.length }
  });

  let successCount = 0;
  let failureCount = 0;

  for (const item of items) {
    const itemSpan = trace.logSpan({
      name: `Process Item ${item.id}`,
      tags: ['item'],
      attributes: { itemId: item.id }
    });

    try {
      await processItem(item);
      itemSpan.update({ status: 'success' });
      successCount++;
    } catch (error) {
      itemSpan.update({
        status: 'failure',
        attributes: { error: String(error) }
      });
      failureCount++;
    }

    itemSpan.end();
  }

  trace.update({
    status: failureCount === 0 ? 'success' : 'failure',
    attributes: {
      successCount,
      failureCount,
      duration: Date.now() - trace.trace.trace.startedAt
    }
  });

  trace.end();
}

Type Definitions

type LogAttributesValue = string | number | boolean;

type TraceStatus = 
  | 'success'
  | 'failure'
  | 'aborted'
  | 'cancelled'
  | 'pending'
  | 'unknown';

interface LogTraceOptions {
  name: string;
  status?: TraceStatus;
  sessionId?: string;
  referenceId?: string;
  tags?: string[];
  attributes?: Record<string, LogAttributesValue>;
}

interface TraceUpdates {
  name?: string;
  status?: TraceStatus;
  tags?: string[];
  attributes?: Record<string, LogAttributesValue>;
}

interface CreateLogTraceRequest {
  projectId: string;
  trace: {
    name: string;
    status: TraceStatus;
    sessionId?: string;
    referenceId: string;
    tags?: string[];
    attributes?: Record<string, LogAttributesValue>;  // LogAttributesValue = string | number | boolean
    startedAt: number;
    endedAt?: number;
  };
}

Best Practices

1. Always Use Try-Finally

// ✅ Good: trace.end() always called
const trace = monitor.logTrace({ name: 'Operation' });
try {
  await doWork();
  trace.update({ status: 'success' });
} finally {
  trace.end();
}

// ❌ Bad: trace.end() might not be called
const trace = monitor.logTrace({ name: 'Operation' });
await doWork();
trace.end(); // Skipped if doWork() throws!

2. Use Meaningful Names

// ✅ Good: Descriptive names
const trace = monitor.logTrace({ name: 'User Registration Flow' });
const trace = monitor.logTrace({ name: 'PDF Processing Pipeline' });
const trace = monitor.logTrace({ name: 'RAG Question Answering' });

// ❌ Bad: Generic names
const trace = monitor.logTrace({ name: 'Request' });
const trace = monitor.logTrace({ name: 'Function' });
const trace = monitor.logTrace({ name: 'Process' });

3. Add Context with Attributes

// ✅ Good: Rich context
const trace = monitor.logTrace({
  name: 'API Request',
  sessionId: userId,
  tags: ['api', 'production', 'premium-tier'],
  attributes: {
    userId,
    endpoint: '/api/chat',
    method: 'POST',
    clientVersion: '2.1.0',
    region: 'us-east-1'
  }
});

4. Update Status Based on Outcome

// ✅ Good: Accurate status tracking
const trace = monitor.logTrace({ name: 'Operation', status: 'pending' });
try {
  await doWork();
  trace.update({ status: 'success' });
} catch (error) {
  trace.update({ status: 'failure' });
  throw error;
} finally {
  trace.end();
}

// ✅ Good: Group related traces
const sessionId = `user-${userId}-${Date.now()}`;

// First trace
const trace1 = monitor.logTrace({
  name: 'Login',
  sessionId
});

// Later traces in same session
const trace2 = monitor.logTrace({
  name: 'Chat Message 1',
  sessionId
});

const trace3 = monitor.logTrace({
  name: 'Chat Message 2',
  sessionId
});

Common Patterns

Pattern 1: Request Handler

async function handleRequest(req: Request) {
  const trace = monitor.logTrace({
    name: `${req.method} ${req.url}`,
    sessionId: req.headers.get('session-id') || undefined,
    tags: ['api', 'http'],
    attributes: {
      method: req.method,
      path: req.url,
      userAgent: req.headers.get('user-agent') || 'unknown'
    }
  });

  try {
    const result = await processRequest(req);
    trace.update({ status: 'success' });
    return result;
  } catch (error) {
    trace.update({ status: 'failure' });
    throw error;
  } finally {
    trace.end();
  }
}

Pattern 2: Background Job

async function runJob(jobId: string) {
  const trace = monitor.logTrace({
    name: 'Background Job',
    referenceId: jobId,
    status: 'pending',
    tags: ['job', 'async']
  });

  try {
    // Job logic with spans...
    trace.update({ status: 'success' });
  } catch (error) {
    trace.update({ status: 'failure' });
  } finally {
    trace.end();
  }
}

Get started

API

SDKs

Proxy

Trace

Trace Class

Overview

Creation

Properties

trace

traceId

Methods

logSpan()

Parameters

Returns

Examples

update()

Parameters

Returns

Examples

end()

Behavior

Returns

Examples

Complete Examples

Example 1: Simple API Request

Example 2: Multi-Step Workflow

Example 3: Nested Operations (RAG Pipeline)

Example 4: Long-Running Background Job

Type Definitions

Best Practices

1. Always Use Try-Finally

2. Use Meaningful Names

3. Add Context with Attributes

4. Update Status Based on Outcome

Common Patterns

Pattern 1: Request Handler

Pattern 2: Background Job

​Trace Class

​Overview

​Creation

​Properties

​trace

​traceId

​Methods

​logSpan()

​Parameters

​Returns

​Examples

​update()

​Parameters

​Returns

​Examples

​end()

​Behavior

​Returns

​Examples

​Complete Examples

​Example 1: Simple API Request

​Example 2: Multi-Step Workflow

​Example 3: Nested Operations (RAG Pipeline)

​Example 4: Long-Running Background Job

​Type Definitions

​Best Practices

​1. Always Use Try-Finally

​2. Use Meaningful Names

​3. Add Context with Attributes

​4. Update Status Based on Outcome

​5. Use Sessions for Related Traces

​Common Patterns

​Pattern 1: Request Handler

​Pattern 2: Background Job

Trace Class

Overview

Creation

Properties

trace

traceId

Methods

logSpan()

Parameters

Returns

Examples

update()

Parameters

Returns

Examples

end()

Behavior

Returns

Examples

Complete Examples

Example 1: Simple API Request

Example 2: Multi-Step Workflow

Example 3: Nested Operations (RAG Pipeline)

Example 4: Long-Running Background Job

Type Definitions

Best Practices

1. Always Use Try-Finally

2. Use Meaningful Names

3. Add Context with Attributes

4. Update Status Based on Outcome

5. Use Sessions for Related Traces

Common Patterns

Pattern 1: Request Handler

Pattern 2: Background Job