Span

Web Client SDK:

import { Span } from '@miradorlabs/web-sdk';

Node.js SDK:

import { Span } from '@miradorlabs/nodejs-sdk';

You don’t instantiate Span directly. Create one with trace.startSpan() or the trace.span() wrapper, and nest with span.startSpan(). See Spans for a conceptual overview.

Properties

id

The span’s W3C Trace Context id (16 lowercase hex characters). Available immediately.

readonly id: string

Also available as getSpanId(): string.

Methods

setAttribute()

Set a single span attribute. Set attributes at creation or synchronously afterwards — before the span first flushes.

setAttribute(key: string, value: string | number | boolean | object): Span

Parameters

Parameter	Type	Description
`key`	`string`	Attribute key
`value`	`string \| number \| boolean \| object`	Attribute value (objects are JSON stringified)

Examples

span.setAttribute('amountIn', '1.5')
    .setAttribute('slippage', 0.5);

setAttributes()

Set multiple span attributes at once.

setAttributes(attrs: Record<string, string | number | boolean | object>): Span

Examples

span.setAttributes({ dex: 'uniswap', pair: 'ETH/USDC', amountIn: '1.5' });

addEvent()

Record an event nested under this span.

addEvent(name: string, details?: string | object, options?: AddEventOptions): Span

Parameters

Parameter	Type	Required	Description
`name`	`string`	Yes	Event name
`details`	`string \| object`	No	Event details (objects are stringified)
`options`	`AddEventOptions`	No	Options with `captureStackTrace`, `timestamp`, etc.

Examples

span.addEvent('quote_received', { price: '3200.50' });

info() / warn() / error()

Convenience methods for recording an event under this span with a severity.

info(name: string, details?: string | object, options?: Omit<AddEventOptions, 'severity'>): Span
warn(name: string, details?: string | object, options?: Omit<AddEventOptions, 'severity'>): Span
error(name: string, details?: string | object, options?: Omit<AddEventOptions, 'severity'>): Span

Examples

span.info('step_started', { index: 0 });
span.warn('retrying', { attempt: 2 });
span.error('step_failed', { code: 'REVERT' });

startSpan()

Open a child span parented to this span.

startSpan(name: string, options?: SpanOptions): Span

Parameters

Parameter	Type	Required	Description
`name`	`string`	Yes	Child span name
`options`	`SpanOptions`	No	Initial `attributes` (parent is this span)

Examples

const parent = trace.startSpan('checkout');
const charge = parent.startSpan('charge');
// ... work ...
charge.end({ status: 'OK' });
parent.end({ status: 'OK' });

end()

End the span, optionally setting an OTLP status and message. Idempotent — a second call is ignored.

end(options?: SpanEndOptions): void

SpanEndOptions

Option	Type	Description
`status`	`'OK' \| 'ERROR' \| 'UNSET'`	Terminal span status (omit for `UNSET`)
`message`	`string`	Status message, typically an error description

Examples

span.end();                                          // UNSET
span.end({ status: 'OK' });
span.end({ status: 'ERROR', message: 'quote timed out' });

isEnded()

Whether end() has been called.

isEnded(): boolean

Method Chaining

setAttribute, setAttributes, addEvent, info, warn, and error return the span for chaining:

const span = trace.startSpan('swap', { attributes: { dex: 'uniswap' } });

span.setAttribute('amountIn', '1.5')
    .info('quote_requested')
    .info('quote_received', { price: '3200.50' });

span.end({ status: 'OK' });

Classes

Web3

Types

Properties

id

Methods

setAttribute()

Parameters

Examples

setAttributes()

Examples

addEvent()

Parameters

Examples

info() / warn() / error()

Examples

startSpan()

Parameters

Examples

end()

SpanEndOptions

Examples

isEnded()

Method Chaining

Next Steps

Spans (Concept)

Trace

​Properties

​id

​Methods

​setAttribute()

​Parameters

​Examples

​setAttributes()

​Examples

​addEvent()

​Parameters

​Examples

​info() / warn() / error()

​Examples

​startSpan()

​Parameters

​Examples

​end()

​SpanEndOptions

​Examples

​isEnded()

​Method Chaining

​Next Steps

Spans (Concept)

Trace

Properties

id

Methods

setAttribute()

Parameters

Examples

setAttributes()

Examples

addEvent()

Parameters

Examples

info() / warn() / error()

Examples

startSpan()

Parameters

Examples

end()

SpanEndOptions

Examples

isEnded()

Method Chaining

Next Steps