Rate Limiting & Retry Logic

const abortError = () => new APIUserAbortError()

const DEFAULT_MAX_RETRIES = 10

const FLOOR_OUTPUT_TOKENS = 3000

const MAX_529_RETRIES = 3

export const BASE_DELAY_MS = 500

// Foreground query sources where the user IS blocking on the result — these

// retry on 529. Everything else (summaries, titles, suggestions, classifiers)

// bails immediately: during a capacity cascade each retry is 3-10× gateway

// amplification, and the user never sees those fail anyway. New sources

// default to no-retry — add here only if the user is waiting on the result.

const FOREGROUND_529_RETRY_SOURCES = new Set<QuerySource>([

  'repl_main_thread',

  'repl_main_thread:outputStyle:custom',

  'repl_main_thread:outputStyle:Explanatory',

  'repl_main_thread:outputStyle:Learning',

  'sdk',

  'agent:custom',

  'agent:default',

  'agent:builtin',

  'compact',

  'hook_agent',

  'hook_prompt',

  'verification_agent',

  'side_question',

  // Security classifiers — must complete for auto-mode correctness.

  // yoloClassifier.ts uses 'auto_mode' (not 'yolo_classifier' — that's

  // type-only). bash_classifier is ant-only; feature-gate so the string

  // tree-shakes out of external builds (excluded-strings.txt).

  'auto_mode',

  ...(feature('BASH_CLASSIFIER') ? (['bash_classifier'] as const) : []),

])

function shouldRetry529(querySource: QuerySource | undefined): boolean {

  // undefined → retry (conservative for untagged call paths)

  return (

    querySource === undefined || FOREGROUND_529_RETRY_SOURCES.has(querySource)

  )

}

// CLAUDE_CODE_UNATTENDED_RETRY: for unattended sessions (ant-only). Retries 429/529

// indefinitely with higher backoff and periodic keep-alive yields so the host

// environment does not mark the session idle mid-wait.

// TODO(ANT-344): the keep-alive via SystemAPIErrorMessage yields is a stopgap

// until there's a dedicated keep-alive channel.

const PERSISTENT_MAX_BACKOFF_MS = 5 * 60 * 1000

const PERSISTENT_RESET_CAP_MS = 6 * 60 * 60 * 1000

const HEARTBEAT_INTERVAL_MS = 30_000

function isPersistentRetryEnabled(): boolean {

  return feature('UNATTENDED_RETRY')

    ? isEnvTruthy(process.env.CLAUDE_CODE_UNATTENDED_RETRY)

    : false

}

function isTransientCapacityError(error: unknown): boolean {

  return (

    is529Error(error) || (error instanceof APIError && error.status === 429)

  )

}

function isStaleConnectionError(error: unknown): boolean {

  if (!(error instanceof APIConnectionError)) {

    return false

  }

  const details = extractConnectionErrorDetails(error)

  return details?.code === 'ECONNRESET' || details?.code === 'EPIPE'

}

export interface RetryContext {