Logging middleware

Use case

Log all HTTP requests and responses for debugging or auditing, with timing information.

Interceptor recipe

import { createClient, isHttpError } from '@parcely/core'

const http = createClient({ baseURL: 'https://api.example.com' })

http.interceptors.request.use((config) => {
  const start = Date.now()
  return { ...config, headers: { ...config.headers }, _startTime: start } as typeof config
})

http.interceptors.response.use(
  (response) => {
    const method = response.config.method ?? 'GET'
    const url = response.config.url ?? ''
    console.log(
      `[HTTP] ${method.toUpperCase()} ${url} -> ${response.status} (${response.statusText})`,
    )
    return response
  },
  (err) => {
    if (isHttpError(err)) {
      const method = err.config.method ?? 'GET'
      const url = err.config.url ?? ''
      console.error(
        `[HTTP] ${method.toUpperCase()} ${url} -> ${err.code} ${err.status ?? ''}`,
      )
    }
    throw err
  },
)

Structured logging

For production, emit structured JSON logs:

http.interceptors.response.use(
  (response) => {
    console.log(JSON.stringify({
      level: 'info',
      type: 'http_response',
      method: response.config.method ?? 'GET',
      url: response.config.url,
      status: response.status,
    }))
    return response
  },
  (err) => {
    if (isHttpError(err)) {
      console.log(JSON.stringify({
        level: 'error',
        type: 'http_error',
        method: err.config.method ?? 'GET',
        url: err.config.url,
        code: err.code,
        status: err.status,
      }))
    }
    throw err
  },
)

Notes

• Sensitive headers are already redacted in response.config and err.config (see Logging and redaction).
• Request interceptors see the live config; response interceptors see the redacted config.
• For detailed logging, see the logging and redaction guide.