feat(low-code): add RateLimitedMultipleTokenAuthenticator component

airbyte_cdk/sources/declarative/auth/__init__.py

@@ -4,5 +4,14 @@
 
 from airbyte_cdk.sources.declarative.auth.jwt import JwtAuthenticator
 from airbyte_cdk.sources.declarative.auth.oauth import DeclarativeOauth2Authenticator
+from airbyte_cdk.sources.declarative.auth.rate_limited_multiple_token import (
+    RateLimitedMultipleTokenAuthenticator,
+    TokenQuota,
+)
 
-__all__ = ["DeclarativeOauth2Authenticator", "JwtAuthenticator"]
+__all__ = [
+    "DeclarativeOauth2Authenticator",
+    "JwtAuthenticator",
+    "RateLimitedMultipleTokenAuthenticator",
+    "TokenQuota",
+]

airbyte_cdk/sources/declarative/auth/rate_limited_multiple_token.py

@@ -0,0 +1,301 @@
+#
+# Copyright (c) 2026 Airbyte, Inc., all rights reserved.
+#
+
+import logging
+import threading
+import time
+from dataclasses import dataclass, field
+from datetime import timedelta
+from itertools import cycle
+from typing import Any, List, Mapping, Optional
+
+import requests
+
+from airbyte_cdk.models import FailureType
+from airbyte_cdk.sources.declarative.auth.declarative_authenticator import DeclarativeAuthenticator
+from airbyte_cdk.sources.streams.call_rate import RequestMatcher
+from airbyte_cdk.sources.streams.http import HttpClient
+from airbyte_cdk.sources.streams.http.requests_native_auth import TokenAuthenticator
+from airbyte_cdk.utils import AirbyteTracedException
+from airbyte_cdk.utils.datetime_helpers import AirbyteDateTime, ab_datetime_now, ab_datetime_parse
+
+
+@dataclass
+class TokenQuota:
+    """A named per-token quota pool.
+
+    `matchers` classify outgoing requests into the pool; a pool with no matchers acts as the
+    default pool. `remaining_path`/`reset_path`/`limit_path` locate the pool's values in the
+    quota status response.
+    """
+
+    name: str
+    remaining_path: List[str]
+    reset_path: List[str]
+    limit_path: Optional[List[str]] = None
+    matchers: List[RequestMatcher] = field(default_factory=list)
+
+
+@dataclass
+class _QuotaState:
+    remaining: int
+    reset_at: AirbyteDateTime
+    limit: int
+
+
+class RateLimitedMultipleTokenAuthenticator(DeclarativeAuthenticator):
+    """Authenticator that rotates between multiple interchangeable tokens with per-token quota tracking.
+
+    Each outgoing request is classified into a quota pool using the pool's request matchers.
+    The active token's counter for the matched pool is decremented locally; when it is exhausted
+    the authenticator rotates to the next token. When all tokens are exhausted for a pool, it
+    waits until the earliest quota reset (bounded by `max_wait_time`) and then refreshes all
+    counters from `quota_status_url`, or raises a transient error if the wait would be too long.
+
+    A proactive throttling budget spreads the last calls over the time remaining until reset:
+    once every token's remaining count for a pool drops below its reserve
+    (`max(budget_min_reserve, budget_reserve_fraction * limit)`), a small delay proportional to
+    `seconds_until_reset / total_remaining` (capped at 10s) is injected before each request.
+
+    Counters are seeded per token from `quota_status_url` on first use and refreshed after an
+    exhaustion wait. All state transitions are guarded by a lock so the authenticator can be
+    shared safely across concurrent streams; sleeps never hold the lock.
+    """
+
+    HEARTBEAT_INTERVAL = 60.0  # Log every 60s during exhaustion wait
+    MAX_BUDGET_DELAY = 10.0  # Cap for the per-request proactive throttling delay
+    MIN_EXHAUSTION_WAIT = 5.0  # Floor for the exhaustion wait, so stale reset timestamps can't cause a refresh busy-loop
+
+    def __init__(
+        self,
+        tokens: List[str],
+        quotas: List[TokenQuota],
+        quota_status_url: str,
+        quota_status_http_method: str = "GET",
+        quota_status_headers: Optional[Mapping[str, str]] = None,
+        auth_method: str = "Bearer",
+        header: str = "Authorization",
+        max_wait_time: timedelta = timedelta(hours=2),
+        budget_reserve_fraction: float = 0.1,
+        budget_min_reserve: int = 50,
+    ) -> None:
+        if not tokens:
+            raise AirbyteTracedException(
+                failure_type=FailureType.config_error,
+                internal_message="RateLimitedMultipleTokenAuthenticator requires at least one token",
+                message="Authentication tokens are missing from the configuration.",
+            )
+        if not quotas:
+            raise ValueError(
+                "RateLimitedMultipleTokenAuthenticator requires at least one quota pool"
+            )
+        self._logger = logging.getLogger("airbyte")
+        self._tokens = list(tokens)
+        self._quotas = quotas
+        self._quota_status_url = quota_status_url
+        self._quota_status_http_method = quota_status_http_method
+        self._quota_status_headers = dict(quota_status_headers or {})
+        self._auth_method = auth_method
+        self._header = header
+        self._max_wait_time = max_wait_time
+        self._budget_reserve_fraction = budget_reserve_fraction
+        self._budget_min_reserve = budget_min_reserve
+
+        self._lock = threading.RLock()
+        self._refresh_lock = threading.Lock()
+        self._initialized = False
+        self._budget_logged = False
+        self._states: dict[str, dict[str, _QuotaState]] = {}
+        self._token_to_http_client: Mapping[str, HttpClient] = {
+            token: HttpClient(
+                name="quota_status",
+                logger=self._logger,
+                authenticator=TokenAuthenticator(
+                    token, auth_method=self._auth_method, auth_header=self._header
+                ),
+                use_cache=False,  # quota values change frequently; never reuse cached responses
+            )
+            for token in self._tokens
+        }
+        self._tokens_iter = cycle(self._tokens)
+        self._active_token = next(self._tokens_iter)
+
+    @property
+    def auth_header(self) -> str:
+        return self._header
+
+    @property
+    def token(self) -> str:
+        with self._lock:
+            return f"{self._auth_method} {self._active_token}".strip()
+
+    def __call__(self, request: requests.PreparedRequest) -> Any:
+        """Attach the HTTP headers required to authenticate on the HTTP request"""
+        self._ensure_initialized()
+        quota = self._match_quota(request)
+        token = self._acquire_call(quota)
+        request.headers[self._header] = f"{self._auth_method} {token}".strip()
+        return request
+
+    def _ensure_initialized(self) -> None:
+        if self._initialized:
+            return
+        with self._refresh_lock:
+            if not self._initialized:
+                self._seed_all_tokens()
+                self._initialized = True
+
+    def _match_quota(self, request: requests.PreparedRequest) -> TokenQuota:
+        default_quota: Optional[TokenQuota] = None
+        for quota in self._quotas:
+            if quota.matchers:
+                if any(matcher(request) for matcher in quota.matchers):
+                    return quota
+            elif default_quota is None:
+                default_quota = quota
+        if default_quota is None:
+            self._logger.debug(
+                "Request %s did not match any quota pool; falling back to '%s'. Consider defining a matcher-less default pool.",
+                request.url,
+                self._quotas[0].name,
+            )
+        return default_quota or self._quotas[0]
+
+    def _acquire_call(self, quota: TokenQuota) -> str:
+        """Reserve one call from the matched pool and return the token it was charged to."""
+        while True:
+            budget_delay: Optional[float] = None
+            wait_for_reset: Optional[float] = None
+            with self._lock:
+                token = self._active_token
+                state = self._states[token][quota.name]
+                if state.remaining > 0:
+                    state.remaining -= 1
+                    budget_delay = self._compute_budget_delay(quota)
+                elif all(self._states[token][quota.name].remaining <= 0 for token in self._tokens):
+                    min_time_to_wait = min(
+                        (
+                            self._states[token][quota.name].reset_at - ab_datetime_now()
+                        ).total_seconds()
+                        for token in self._tokens
+                    )
+                    if min_time_to_wait >= self._max_wait_time.total_seconds():
+                        raise AirbyteTracedException(
+                            failure_type=FailureType.transient_error,
+                            internal_message=f"Rate limits for all tokens (quota: {quota.name}) were reached and the next reset exceeds max_wait_time",
+                            message="Rate limit is exceeded for all provided tokens.",
+                        )
+                    wait_for_reset = min(
+                        max(min_time_to_wait, self.MIN_EXHAUSTION_WAIT),
+                        self._max_wait_time.total_seconds(),
+                    )
+                else:
+                    self._active_token = next(self._tokens_iter)
+                    continue
+
+            if wait_for_reset is not None:
+                self._logger.info(
+                    "All tokens exhausted (quota: %s). Waiting %.0fs until rate limit resets.",
+                    quota.name,
+                    wait_for_reset,
+                )
+                self._sleep_with_heartbeat(wait_for_reset, quota.name)
+                self._refresh_after_exhaustion(quota)
+                continue
+
+            if budget_delay is not None and budget_delay >= 0.1:
+                if not self._budget_logged:
+                    self._logger.info(
+                        "API budget: throttling requests (%.1fs delay) for quota '%s'.",
+                        budget_delay,
+                        quota.name,
+                    )
+                    self._budget_logged = True
+                time.sleep(budget_delay)
+            return token
+
+    def _compute_budget_delay(self, quota: TokenQuota) -> Optional[float]:
+        """Compute the proactive throttling delay. Must be called while holding the lock."""
+        states = [self._states[token][quota.name] for token in self._tokens]
+        if not all(state.remaining <= self._get_budget_reserve(state) for state in states):
+            return None
+
+        active_state = self._states[self._active_token][quota.name]
+        seconds_to_reset = max((active_state.reset_at - ab_datetime_now()).total_seconds(), 0)
+        total_remaining = sum(max(state.remaining, 0) for state in states)
+        if total_remaining <= 0 or seconds_to_reset <= 0:
+            return None
+
+        return min(seconds_to_reset / total_remaining, self.MAX_BUDGET_DELAY)
+
+    def _get_budget_reserve(self, state: _QuotaState) -> float:
+        return max(self._budget_min_reserve, state.limit * self._budget_reserve_fraction)
+
+    def _sleep_with_heartbeat(self, total_seconds: float, quota_name: str) -> None:
+        """Sleep for `total_seconds` in chunks, logging progress so operators can see the connector is not stuck."""
+        remaining = total_seconds
+        while remaining > 0:
+            chunk = min(remaining, self.HEARTBEAT_INTERVAL)
+            time.sleep(chunk)
+            remaining -= chunk
+            if remaining > 0:
+                self._logger.info(
+                    "Rate limit exhausted (quota: %s). Waiting for reset — %.0fs remaining.",
+                    quota_name,
+                    remaining,
+                )
+
+    def _refresh_after_exhaustion(self, quota: TokenQuota) -> None:
+        """Refresh counters after an exhaustion wait. Only one thread refreshes; others re-check state."""
+        with self._refresh_lock:
+            with self._lock:
+                still_exhausted = all(
+                    self._states[token][quota.name].remaining <= 0 for token in self._tokens
+                )
+            if still_exhausted:
+                self._seed_all_tokens()
+
+    def _seed_all_tokens(self) -> None:
+        states = {token: self._fetch_quota_states(token) for token in self._tokens}
+        with self._lock:
+            self._states = states
+            self._budget_logged = False
+
+    def _fetch_quota_states(self, token: str) -> dict[str, _QuotaState]:
+        http_client = self._token_to_http_client[token]
+        _, response = http_client.send_request(
+            http_method=self._quota_status_http_method,
+            url=self._quota_status_url,
+            headers=self._quota_status_headers,
+            request_kwargs={},
+        )
+        response_body = response.json()
+
+        states = {}
+        for quota in self._quotas:
+            remaining = self._extract_path(response_body, quota.remaining_path)
+            reset = self._extract_path(response_body, quota.reset_path)
+            limit = (
+                self._extract_path(response_body, quota.limit_path)
+                if quota.limit_path
+                else remaining
+            )
+            states[quota.name] = _QuotaState(
+                remaining=int(remaining),
+                reset_at=ab_datetime_parse(reset),
+                limit=int(limit),
+            )
+        return states
+
+    def _extract_path(self, response_body: Mapping[str, Any], path: List[str]) -> Any:
+        value: Any = response_body
+        for key in path:
+            if not isinstance(value, Mapping) or key not in value:
+                raise AirbyteTracedException(
+                    failure_type=FailureType.config_error,
+                    internal_message=f"Quota status response did not contain expected path: {path}",
+                    message="Quota status response is missing an expected field.",
+                )
+            value = value[key]
+        return value