Logflare Transport Server Deno Bun

Ships logs to Logflare using the HTTP transport with Logflare-specific configuration. Features include:

• Automatic Logflare JSON format
• Built on top of the robust HTTP transport
• Retry logic with exponential backoff
• Rate limiting support
• Batch sending with configurable size and timeout
• Error and debug callbacks
• Support for self-hosted Logflare instances

Transport Source

Installation

npm

npm install loglayer @loglayer/transport-logflare serialize-error

pnpm

pnpm add loglayer @loglayer/transport-logflare serialize-error

yarn

yarn add loglayer @loglayer/transport-logflare serialize-error

Basic Usage

Logflare free tier issues

The free tier has very low rate limits which can be easily exceeded. You may find yourself getting 503: Service Unavailable codes if you exceed the rate limit. Make sure to define the onError() callback to catch this and adjust batch timings accordingly.

import { LogLayer } from 'loglayer'
import { LogflareTransport } from "@loglayer/transport-logflare"
import { serializeError } from "serialize-error";

const log = new LogLayer({
  errorSerializer: serializeError,
  contextFieldName: null, // recommended based on testing
  metadataFieldName: null, // recommended based on testing
  transport: new LogflareTransport({
    sourceId: "YOUR-SOURCE-ID",
    apiKey: "YOUR-API-KEY",
    onError: (err) => {
      console.error('Failed to send logs to Logflare:', err);
    },
    onDebug: (entry) => {
      console.log('Log entry being sent to Logflare:', entry);
    },
    onDebugReqRes: ({ req, res }) => {
      console.log("=== HTTP Request ===");
      console.log("URL:", req.url);
      console.log("Method:", req.method);
      console.log("Headers:", JSON.stringify(req.headers, null, 2));
      console.log("Body:", typeof req.body === "string" ? req.body : `[Uint8Array: ${req.body.length} bytes]`);
      console.log("=== HTTP Response ===");
      console.log("Status:", res.status, res.statusText);
      console.log("Headers:", JSON.stringify(res.headers, null, 2));
      console.log("Body:", res.body);
      console.log("===================");
    },
  })
})

// Use the logger
log.info("This is a test message");
log.withMetadata({ userId: "123" }).error("User not found");

Configuration

Required Parameters

Name	Type	Description
sourceId	string	Your Logflare source ID
apiKey	string	Your Logflare API key

Optional Parameters

Name	Type	Default	Description
url	string	"https://api.logflare.app"	Custom Logflare API endpoint (for self-hosted instances)
enabled	boolean	true	Whether the transport is enabled
level	"trace" | "debug" | "info" | "warn" | "error" | "fatal"	"trace"	Minimum log level to process. Logs below this level will be filtered out

HTTP Transport Optional Parameters

General Parameters

Name	Type	Default	Description
enabled	boolean	true	Whether the transport is enabled
level	"trace" | "debug" | "info" | "warn" | "error" | "fatal"	"trace"	Minimum log level to process. Logs below this level will be filtered out
method	string	"POST"	HTTP method to use for requests
headers	Record<string, string> | (() => Record<string, string>)	{}	Headers to include in the request. Can be an object or a function that returns headers
contentType	string	"application/json"	Content type for single log requests. User-specified headers take precedence
compression	boolean	false	Whether to use gzip compression
maxRetries	number	3	Number of retry attempts before giving up
retryDelay	number	1000	Base delay between retries in milliseconds
respectRateLimit	boolean	true	Whether to respect rate limiting by waiting when a 429 response is received
maxLogSize	number	1048576	Maximum size of a single log entry in bytes (1MB)
maxPayloadSize	number	5242880	Maximum size of the payload (uncompressed) in bytes (5MB)
enableNextJsEdgeCompat	boolean	false	Whether to enable Next.js Edge compatibility

Debug Parameters

Name	Type	Default	Description
onError	(err: Error) => void	-	Error handling callback
onDebug	(entry: Record<string, any>) => void	-	Debug callback for inspecting log entries before they are sent
onDebugReqRes	(reqRes: { req: { url: string; method: string; headers: Record<string, string>; body: string | Uint8Array }; res: { status: number; statusText: string; headers: Record<string, string>; body: string } }) => void	-	Debug callback for inspecting HTTP requests and responses. Provides complete request/response details including headers and body content

Batch Parameters

Name	Type	Default	Description
batchContentType	string	"application/json"	Content type for batch log requests. User-specified headers take precedence
enableBatchSend	boolean	true	Whether to enable batch sending
batchSize	number	100	Number of log entries to batch before sending
batchSendTimeout	number	5000	Timeout in milliseconds for sending batches regardless of size
batchSendDelimiter	string	"\n"	Delimiter to use between log entries in batch mode
batchMode	"delimiter" | "field" | "array"	"delimiter"	Batch mode for sending multiple log entries. "delimiter" joins entries with a delimiter, "field" wraps an array of entries in an object with a field name, "array" sends entries as a plain JSON array of objects
batchFieldName	string	-	Field name to wrap batch entries in when batchMode is "field"

For more details on these options, see the HTTP transport documentation.