Skip to main content
const span = await tracia.spans.get(spanId);
Retrieve a single span by its ID, including full input/output details.

​
Parameters

ParameterTypeRequiredDescription
spanIdstringYesThe span ID (e.g., sp_abc123def456)

​
Response

interface Span {
  id: string;
  spanId: string;
  traceId: string | null;
  parentSpanId: string | null;
  promptSlug: string | null;
  promptVersion: number | null;
  model: string;
  provider: string;
  input: { messages: PromptMessage[] };
  variables: Record<string, string> | null;
  output: string | null;
  status: 'SUCCESS' | 'ERROR';
  error: string | null;
  latencyMs: number;
  inputTokens: number;
  outputTokens: number;
  totalTokens: number;
  cost: number | null;
  tags: string[];
  userId: string | null;
  sessionId: string | null;
  createdAt: string;
}

​
Examples

​
Basic Usage

const span = await tracia.spans.get('sp_abc123def456');

console.log(`Model: ${span.model} (${span.provider})`);
console.log(`Status: ${span.status}`);
console.log(`Latency: ${span.latencyMs}ms`);

​
Viewing Input and Output

const span = await tracia.spans.get('sp_abc123def456');

console.log('Input messages:');
span.input.messages.forEach(msg => {
  console.log(`  [${msg.role}]: ${msg.content.slice(0, 100)}...`);
});

console.log('\nOutput:');
console.log(span.output);

​
Checking Variables Used

const span = await tracia.spans.get('sp_abc123def456');

if (span.variables) {
  console.log('Variables used:');
  Object.entries(span.variables).forEach(([key, value]) => {
    console.log(`  ${key}: ${value}`);
  });
}

​
Checking Trace Session

const span = await tracia.spans.get('sp_abc123def456');

if (span.traceId) {
  console.log(`Part of trace session: ${span.traceId}`);
}

if (span.parentSpanId) {
  console.log(`Parent span: ${span.parentSpanId}`);
}

​
Handling Errors

const span = await tracia.spans.get('sp_abc123def456');

if (span.status === 'ERROR') {
  console.error(`Span failed: ${span.error}`);
} else {
  console.log('Span succeeded');
  console.log(`Tokens: ${span.inputTokens} in, ${span.outputTokens} out`);
  console.log(`Cost: $${span.cost?.toFixed(4) || 'N/A'}`);
}

​
Debugging a Prompt Run

const span = await tracia.spans.get('sp_abc123def456');

console.log('=== Span Debug Info ===');
console.log(`Span ID: ${span.spanId}`);
console.log(`Trace ID: ${span.traceId || 'N/A'}`);
console.log(`Parent Span: ${span.parentSpanId || 'N/A'}`);
console.log(`Prompt: ${span.promptSlug || 'runLocal'} v${span.promptVersion || 'N/A'}`);
console.log(`Model: ${span.model} (${span.provider})`);
console.log(`Status: ${span.status}`);
console.log(`Latency: ${span.latencyMs}ms`);
console.log(`Tokens: ${span.inputTokens} + ${span.outputTokens} = ${span.totalTokens}`);
console.log(`Cost: $${span.cost?.toFixed(4) || 'N/A'}`);
console.log(`Tags: ${span.tags.join(', ') || 'none'}`);
console.log(`User ID: ${span.userId || 'N/A'}`);
console.log(`Session ID: ${span.sessionId || 'N/A'}`);
console.log(`Created: ${span.createdAt}`);

​
Error Handling

import { TraciaError, TraciaErrorCode } from 'tracia';

try {
  const span = await tracia.spans.get('sp_abc123def456');
} catch (error) {
  if (error instanceof TraciaError) {
    if (error.code === TraciaErrorCode.NOT_FOUND) {
      console.error('Span does not exist');
    }
  }
}