Function buildFetch

src/services/api/client.ts:358–401

(
  fetchOverride: ClientOptions['fetch'],
  source: string | undefined,
)

export const CLIENT_REQUEST_ID_HEADER = 'x-client-request-id'

function buildFetch(
  fetchOverride: ClientOptions['fetch'],
  source: string | undefined,
): ClientOptions['fetch'] {
  // eslint-disable-next-line eslint-plugin-n/no-unsupported-features/node-builtins
  let inner = fetchOverride ?? globalThis.fetch

  // Wrap with x402 payment handler for automatic 402 Payment Required handling
  try {
    const { wrapFetchWithX402, isX402Enabled } =
      require('../x402/index.js') as typeof import('../x402/index.js')
    if (isX402Enabled()) {
      inner = wrapFetchWithX402(inner as typeof globalThis.fetch) as typeof inner
    }
  } catch {
    // x402 module not available, skip
  }

  // Only send to the first-party API — Bedrock/Vertex/Foundry don't log it
  // and unknown headers risk rejection by strict proxies (inc-4029 class).
  const injectClientRequestId =
    getAPIProvider() === 'firstParty' && isFirstPartyAnthropicBaseUrl()
  return (input, init) => {
    // eslint-disable-next-line eslint-plugin-n/no-unsupported-features/node-builtins
    const headers = new Headers(init?.headers)
    // Generate a client-side request ID so timeouts (which return no server
    // request ID) can still be correlated with server logs by the API team.
    // Callers that want to track the ID themselves can pre-set the header.
    if (injectClientRequestId && !headers.has(CLIENT_REQUEST_ID_HEADER)) {
      headers.set(CLIENT_REQUEST_ID_HEADER, randomUUID())
    }
    try {
      // eslint-disable-next-line eslint-plugin-n/no-unsupported-features/node-builtins
      const url = input instanceof Request ? input.url : String(input)
      const id = headers.get(CLIENT_REQUEST_ID_HEADER)
      logForDebugging(
        `[API REQUEST] ${new URL(url).pathname}${id ? ` ${CLIENT_REQUEST_ID_HEADER}=${id}` : ''} source=${source ?? 'unknown'}`,
      )
    } catch {
      // never let logging crash the fetch
    }
    return inner(input, { ...init, headers })
  }
}