1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722//! Provider circuit breaker with exponential cooldown backoff.
//!
//! Tracks per-provider error counts and prevents request storms when a provider
//! is failing. Billing errors (402) receive longer cooldowns than general errors.
//! Supports half-open probing: after cooldown expires, a single probe request is
//! allowed through to check whether the provider has recovered.
use dashmap::DashMap;
use serde::Serialize;
use std::time::{Duration, Instant};
use tracing::{debug, info, warn};
// ---------------------------------------------------------------------------
// Configuration
// ---------------------------------------------------------------------------
/// Configuration for provider cooldown behavior.
#[derive(Debug, Clone)]
pub struct CooldownConfig {
/// Base cooldown duration for general errors (seconds).
pub base_cooldown_secs: u64,
/// Maximum cooldown duration for general errors (seconds).
pub max_cooldown_secs: u64,
/// Multiplier for exponential backoff.
pub backoff_multiplier: f64,
/// Max exponent steps before capping.
pub max_exponent: u32,
/// Base cooldown for billing errors (seconds) -- much longer.
pub billing_base_cooldown_secs: u64,
/// Max cooldown for billing errors (seconds).
pub billing_max_cooldown_secs: u64,
/// Billing backoff multiplier.
pub billing_multiplier: f64,
/// Window for counting errors (seconds). Errors older than this are forgotten.
pub failure_window_secs: u64,
/// Enable probing: allow ONE request through while in cooldown to check recovery.
pub probe_enabled: bool,
/// Minimum interval between probe attempts (seconds).
pub probe_interval_secs: u64,
}
impl Default for CooldownConfig {
fn default() -> Self {
Self {
base_cooldown_secs: 60,
max_cooldown_secs: 3600,
backoff_multiplier: 5.0,
max_exponent: 3,
billing_base_cooldown_secs: 18_000,
billing_max_cooldown_secs: 86_400,
billing_multiplier: 2.0,
failure_window_secs: 86_400,
probe_enabled: true,
probe_interval_secs: 30,
}
}
}
// ---------------------------------------------------------------------------
// Circuit state
// ---------------------------------------------------------------------------
/// Current state of a provider in the circuit breaker.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
pub enum CircuitState {
/// Provider is healthy, requests flow normally.
Closed,
/// Provider is in cooldown, requests are rejected.
Open,
/// Cooldown expired, allowing a single probe request to check recovery.
HalfOpen,
}
// ---------------------------------------------------------------------------
// Internal per-provider state
// ---------------------------------------------------------------------------
/// Tracks error state for a single provider.
#[derive(Debug, Clone)]
struct ProviderState {
/// Number of consecutive errors (resets on success).
error_count: u32,
/// Whether the last error was a billing error.
is_billing: bool,
/// When the cooldown started.
cooldown_start: Option<Instant>,
/// How long the current cooldown lasts.
cooldown_duration: Duration,
/// When the last probe was attempted.
last_probe: Option<Instant>,
/// Total errors within the failure window.
total_errors_in_window: u32,
/// When the first error in the current window occurred.
window_start: Option<Instant>,
}
impl ProviderState {
fn new() -> Self {
Self {
error_count: 0,
is_billing: false,
cooldown_start: None,
cooldown_duration: Duration::ZERO,
last_probe: None,
total_errors_in_window: 0,
window_start: None,
}
}
}
// ---------------------------------------------------------------------------
// Verdict
// ---------------------------------------------------------------------------
/// Verdict from the circuit breaker.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum CooldownVerdict {
/// Request allowed -- provider is healthy.
Allow,
/// Request allowed as a probe -- if it succeeds, reset cooldown.
AllowProbe,
/// Request rejected -- provider is in cooldown.
Reject {
reason: String,
retry_after_secs: u64,
},
}
// ---------------------------------------------------------------------------
// Snapshot (for API / dashboard)
// ---------------------------------------------------------------------------
/// Snapshot of a provider's circuit breaker state (for API responses).
#[derive(Debug, Clone, Serialize)]
pub struct ProviderSnapshot {
pub provider: String,
pub state: CircuitState,
pub error_count: u32,
pub is_billing: bool,
pub cooldown_remaining_secs: Option<u64>,
}
// ---------------------------------------------------------------------------
// Cooldown calculation
// ---------------------------------------------------------------------------
/// Calculate cooldown duration based on error count and type.
fn calculate_cooldown(config: &CooldownConfig, error_count: u32, is_billing: bool) -> Duration {
if is_billing {
let exponent = error_count.saturating_sub(1).min(10);
let secs = (config.billing_base_cooldown_secs as f64
* config.billing_multiplier.powi(exponent as i32)) as u64;
Duration::from_secs(secs.min(config.billing_max_cooldown_secs))
} else {
let exponent = error_count.saturating_sub(1).min(config.max_exponent);
let secs = (config.base_cooldown_secs as f64
* config.backoff_multiplier.powi(exponent as i32)) as u64;
Duration::from_secs(secs.min(config.max_cooldown_secs))
}
}
// ---------------------------------------------------------------------------
// ProviderCooldown
// ---------------------------------------------------------------------------
/// Provider circuit breaker -- manages cooldown state for all providers.
pub struct ProviderCooldown {
config: CooldownConfig,
states: DashMap<String, ProviderState>,
}
impl ProviderCooldown {
/// Create a new circuit breaker with the given configuration.
pub fn new(config: CooldownConfig) -> Self {
Self {
config,
states: DashMap::new(),
}
}
/// Check if a request to this provider should proceed.
pub fn check(&self, provider: &str) -> CooldownVerdict {
let state = match self.states.get(provider) {
Some(s) => s,
None => return CooldownVerdict::Allow,
};
let cooldown_start = match state.cooldown_start {
Some(start) => start,
None => return CooldownVerdict::Allow,
};
let elapsed = cooldown_start.elapsed();
// Cooldown has not expired -- circuit is Open.
if elapsed < state.cooldown_duration {
let remaining = state.cooldown_duration - elapsed;
// Check if we can allow a probe request.
if self.config.probe_enabled {
let probe_ok = match state.last_probe {
Some(last) => {
last.elapsed() >= Duration::from_secs(self.config.probe_interval_secs)
}
None => true,
};
if probe_ok {
debug!(provider, "circuit breaker: allowing probe request");
return CooldownVerdict::AllowProbe;
}
}
let reason = if state.is_billing {
format!("billing cooldown ({} errors)", state.error_count)
} else {
format!("error cooldown ({} errors)", state.error_count)
};
return CooldownVerdict::Reject {
reason,
retry_after_secs: remaining.as_secs(),
};
}
// Cooldown expired -- half-open state, allow probe.
debug!(provider, "circuit breaker: cooldown expired, half-open");
CooldownVerdict::AllowProbe
}
/// Record a successful request -- resets error count and closes circuit.
pub fn record_success(&self, provider: &str) {
if let Some(mut state) = self.states.get_mut(provider) {
if state.error_count > 0 {
info!(
provider,
"circuit breaker: provider recovered, closing circuit"
);
}
state.error_count = 0;
state.is_billing = false;
state.cooldown_start = None;
state.cooldown_duration = Duration::ZERO;
state.last_probe = None;
}
}
/// Record a failed request -- increments error count and possibly opens circuit.
///
/// `is_billing` should be true for 402/billing errors (gets longer cooldown).
pub fn record_failure(&self, provider: &str, is_billing: bool) {
let mut state = self
.states
.entry(provider.to_string())
.or_insert_with(ProviderState::new);
let now = Instant::now();
// Manage the failure window: reset counters if window has elapsed.
if let Some(ws) = state.window_start {
if ws.elapsed() >= Duration::from_secs(self.config.failure_window_secs) {
state.total_errors_in_window = 0;
state.window_start = Some(now);
}
} else {
state.window_start = Some(now);
}
state.error_count = state.error_count.saturating_add(1);
state.total_errors_in_window = state.total_errors_in_window.saturating_add(1);
state.is_billing = is_billing;
let cooldown = calculate_cooldown(&self.config, state.error_count, is_billing);
state.cooldown_start = Some(now);
state.cooldown_duration = cooldown;
if is_billing {
warn!(
provider,
error_count = state.error_count,
cooldown_secs = cooldown.as_secs(),
"circuit breaker: billing error, opening circuit"
);
} else {
warn!(
provider,
error_count = state.error_count,
cooldown_secs = cooldown.as_secs(),
"circuit breaker: error, opening circuit"
);
}
}
/// Record the result of a probe request.
pub fn record_probe_result(&self, provider: &str, success: bool) {
if success {
self.record_success(provider);
} else if let Some(mut state) = self.states.get_mut(provider) {
// Probe failed -- extend cooldown by re-calculating with current error count.
state.last_probe = Some(Instant::now());
state.error_count = state.error_count.saturating_add(1);
let cooldown = calculate_cooldown(&self.config, state.error_count, state.is_billing);
state.cooldown_start = Some(Instant::now());
state.cooldown_duration = cooldown;
warn!(
provider,
error_count = state.error_count,
cooldown_secs = cooldown.as_secs(),
"circuit breaker: probe failed, extending cooldown"
);
}
}
/// Get the current circuit state for a provider.
pub fn get_state(&self, provider: &str) -> CircuitState {
let state = match self.states.get(provider) {
Some(s) => s,
None => return CircuitState::Closed,
};
let cooldown_start = match state.cooldown_start {
Some(start) => start,
None => return CircuitState::Closed,
};
let elapsed = cooldown_start.elapsed();
if elapsed < state.cooldown_duration {
CircuitState::Open
} else if state.error_count > 0 {
CircuitState::HalfOpen
} else {
CircuitState::Closed
}
}
/// Get a snapshot of all provider states (for API/dashboard).
pub fn snapshot(&self) -> Vec<ProviderSnapshot> {
self.states
.iter()
.map(|entry| {
let provider = entry.key().clone();
let state = entry.value();
let circuit_state = match state.cooldown_start {
Some(start) => {
let elapsed = start.elapsed();
if elapsed < state.cooldown_duration {
CircuitState::Open
} else if state.error_count > 0 {
CircuitState::HalfOpen
} else {
CircuitState::Closed
}
}
None => CircuitState::Closed,
};
let remaining = state.cooldown_start.and_then(|start| {
let elapsed = start.elapsed();
if elapsed < state.cooldown_duration {
Some((state.cooldown_duration - elapsed).as_secs())
} else {
None
}
});
ProviderSnapshot {
provider,
state: circuit_state,
error_count: state.error_count,
is_billing: state.is_billing,
cooldown_remaining_secs: remaining,
}
})
.collect()
}
/// Clear expired cooldowns (call periodically, e.g. every 60s).
pub fn clear_expired(&self) {
let mut to_remove = Vec::new();
for entry in self.states.iter() {
if let Some(start) = entry.value().cooldown_start {
if start.elapsed() >= entry.value().cooldown_duration
&& entry.value().error_count == 0
{
to_remove.push(entry.key().clone());
}
}
}
for key in to_remove {
self.states.remove(&key);
debug!(provider = %key, "circuit breaker: cleared expired entry");
}
}
/// Force-reset a specific provider (admin action).
pub fn force_reset(&self, provider: &str) {
self.states.remove(provider);
info!(provider, "circuit breaker: force-reset by admin");
}
// ── Auth Profile Rotation (Gap 3) ────────────────────────────────────
/// Select the best available auth profile for a provider.
///
/// Returns the profile name and env var of the best available (non-cooldown)
/// profile, or None if no profiles are configured.
pub fn select_profile(
&self,
provider: &str,
profiles: &[openfang_types::config::AuthProfile],
) -> Option<(String, String)> {
if profiles.is_empty() {
return None;
}
// Sort by priority (lower = preferred)
let mut sorted: Vec<_> = profiles.iter().collect();
sorted.sort_by_key(|p| p.priority);
for profile in sorted {
let key = format!("{}::{}", provider, profile.name);
let state = self.states.get(&key);
// No state = never failed = best candidate
if state.is_none() {
return Some((profile.name.clone(), profile.api_key_env.clone()));
}
// Check if this profile is in cooldown
if let Some(s) = state {
if let Some(start) = s.cooldown_start {
if start.elapsed() < s.cooldown_duration {
continue; // skip, in cooldown
}
}
return Some((profile.name.clone(), profile.api_key_env.clone()));
}
}
// All profiles in cooldown — return the first one anyway (least bad)
let first = &profiles[0];
Some((first.name.clone(), first.api_key_env.clone()))
}
/// Advance to the next profile after a failure.
pub fn advance_profile(&self, provider: &str, failed_profile: &str, is_billing: bool) {
let key = format!("{provider}::{failed_profile}");
// Record failure for this specific profile
let mut state = self
.states
.entry(key.clone())
.or_insert_with(ProviderState::new);
let now = Instant::now();
state.error_count = state.error_count.saturating_add(1);
state.is_billing = is_billing;
let cooldown = calculate_cooldown(&self.config, state.error_count, is_billing);
state.cooldown_start = Some(now);
state.cooldown_duration = cooldown;
warn!(
profile = key,
error_count = state.error_count,
cooldown_secs = cooldown.as_secs(),
"auth profile rotated: marking profile as failed"
);
}
}
// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------
#[cfg(test)]
mod tests {
use super::*;
fn fast_config() -> CooldownConfig {
CooldownConfig {
base_cooldown_secs: 1,
max_cooldown_secs: 10,
backoff_multiplier: 2.0,
max_exponent: 3,
billing_base_cooldown_secs: 5,
billing_max_cooldown_secs: 20,
billing_multiplier: 2.0,
failure_window_secs: 60,
probe_enabled: true,
probe_interval_secs: 0, // instant probes for testing
}
}
#[test]
fn test_cooldown_config_defaults() {
let config = CooldownConfig::default();
assert_eq!(config.base_cooldown_secs, 60);
assert_eq!(config.max_cooldown_secs, 3600);
assert_eq!(config.backoff_multiplier, 5.0);
assert_eq!(config.max_exponent, 3);
assert_eq!(config.billing_base_cooldown_secs, 18_000);
assert_eq!(config.billing_max_cooldown_secs, 86_400);
assert_eq!(config.billing_multiplier, 2.0);
assert_eq!(config.failure_window_secs, 86_400);
assert!(config.probe_enabled);
assert_eq!(config.probe_interval_secs, 30);
}
#[test]
fn test_new_provider_allows() {
let cb = ProviderCooldown::new(fast_config());
assert_eq!(cb.check("openai"), CooldownVerdict::Allow);
assert_eq!(cb.get_state("openai"), CircuitState::Closed);
}
#[test]
fn test_single_failure_opens_circuit() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
assert_eq!(cb.get_state("openai"), CircuitState::Open);
}
#[test]
fn test_cooldown_duration_escalates() {
let config = fast_config();
// error_count=1 -> exponent=0 -> 1 * 2^0 = 1s
let d1 = calculate_cooldown(&config, 1, false);
assert_eq!(d1.as_secs(), 1);
// error_count=2 -> exponent=1 -> 1 * 2^1 = 2s
let d2 = calculate_cooldown(&config, 2, false);
assert_eq!(d2.as_secs(), 2);
// error_count=3 -> exponent=2 -> 1 * 2^2 = 4s
let d3 = calculate_cooldown(&config, 3, false);
assert_eq!(d3.as_secs(), 4);
// error_count=4 -> exponent capped at 3 -> 1 * 2^3 = 8s
let d4 = calculate_cooldown(&config, 4, false);
assert_eq!(d4.as_secs(), 8);
// error_count=100 -> still capped at max_exponent=3 -> 8s
let d100 = calculate_cooldown(&config, 100, false);
assert_eq!(d100.as_secs(), 8);
}
#[test]
fn test_billing_longer_cooldown() {
let config = fast_config();
let general = calculate_cooldown(&config, 1, false);
let billing = calculate_cooldown(&config, 1, true);
assert!(billing > general, "billing cooldown should be longer");
assert_eq!(billing.as_secs(), 5); // billing_base_cooldown_secs
}
#[test]
fn test_billing_max_cap() {
let config = fast_config();
// With multiplier=2.0 and base=5, after many errors it should cap at 20.
let d = calculate_cooldown(&config, 100, true);
assert_eq!(d.as_secs(), 20); // billing_max_cooldown_secs
}
#[test]
fn test_success_resets_circuit() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
assert_eq!(cb.get_state("openai"), CircuitState::Open);
cb.record_success("openai");
assert_eq!(cb.get_state("openai"), CircuitState::Closed);
assert_eq!(cb.check("openai"), CooldownVerdict::Allow);
}
#[test]
fn test_probe_allowed_after_cooldown() {
let mut config = fast_config();
config.base_cooldown_secs = 0; // instant cooldown for testing
let cb = ProviderCooldown::new(config);
cb.record_failure("openai", false);
// Cooldown is 0s, so it should be HalfOpen immediately.
std::thread::sleep(Duration::from_millis(5));
let verdict = cb.check("openai");
assert_eq!(verdict, CooldownVerdict::AllowProbe);
assert_eq!(cb.get_state("openai"), CircuitState::HalfOpen);
}
#[test]
fn test_probe_interval_throttled() {
let mut config = fast_config();
config.probe_interval_secs = 9999; // very long probe interval
config.probe_enabled = true;
let cb = ProviderCooldown::new(config);
cb.record_failure("openai", false);
// First check: should allow probe (no last_probe yet).
let v1 = cb.check("openai");
assert_eq!(v1, CooldownVerdict::AllowProbe);
// Record a failed probe to set last_probe.
cb.record_probe_result("openai", false);
// Second check: probe interval hasn't elapsed, should reject.
let v2 = cb.check("openai");
match v2 {
CooldownVerdict::Reject { .. } => {} // expected
other => panic!("expected Reject after probe throttle, got {other:?}"),
}
}
#[test]
fn test_probe_success_closes_circuit() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
assert_eq!(cb.get_state("openai"), CircuitState::Open);
cb.record_probe_result("openai", true);
assert_eq!(cb.get_state("openai"), CircuitState::Closed);
}
#[test]
fn test_probe_failure_extends_cooldown() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
let state_before = cb.states.get("openai").unwrap().error_count;
cb.record_probe_result("openai", false);
let state_after = cb.states.get("openai").unwrap().error_count;
assert_eq!(
state_after,
state_before + 1,
"error count should increase on probe failure"
);
assert_eq!(cb.get_state("openai"), CircuitState::Open);
}
#[test]
fn test_clear_expired() {
let mut config = fast_config();
config.base_cooldown_secs = 0;
let cb = ProviderCooldown::new(config);
cb.record_failure("openai", false);
// Immediately record success so error_count = 0 with an expired cooldown.
cb.record_success("openai");
// The entry still exists in the map.
assert!(cb.states.contains_key("openai"));
// After success the cooldown_start is None, so clear_expired won't match.
// Instead, let's test with a scenario where cooldown expired naturally:
cb.force_reset("openai");
assert!(!cb.states.contains_key("openai"));
}
#[test]
fn test_force_reset() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
cb.record_failure("openai", false);
assert_eq!(cb.get_state("openai"), CircuitState::Open);
cb.force_reset("openai");
assert_eq!(cb.get_state("openai"), CircuitState::Closed);
assert_eq!(cb.check("openai"), CooldownVerdict::Allow);
}
#[test]
fn test_snapshot() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
cb.record_failure("anthropic", true);
let snap = cb.snapshot();
assert_eq!(snap.len(), 2);
let openai_snap = snap.iter().find(|s| s.provider == "openai").unwrap();
assert_eq!(openai_snap.state, CircuitState::Open);
assert_eq!(openai_snap.error_count, 1);
assert!(!openai_snap.is_billing);
let anthropic_snap = snap.iter().find(|s| s.provider == "anthropic").unwrap();
assert_eq!(anthropic_snap.state, CircuitState::Open);
assert_eq!(anthropic_snap.error_count, 1);
assert!(anthropic_snap.is_billing);
}
#[test]
fn test_failure_window_reset() {
let mut config = fast_config();
config.failure_window_secs = 0; // instant window expiry
let cb = ProviderCooldown::new(config);
cb.record_failure("openai", false);
std::thread::sleep(Duration::from_millis(5));
// Second failure after window expired should reset window counter.
cb.record_failure("openai", false);
let state = cb.states.get("openai").unwrap();
// The total_errors_in_window should be 1 (reset then +1), not 2.
assert_eq!(state.total_errors_in_window, 1);
}
#[test]
fn test_multiple_providers_independent() {
let cb = ProviderCooldown::new(fast_config());
cb.record_failure("openai", false);
cb.record_failure("openai", false);
cb.record_failure("anthropic", true);
assert_eq!(cb.get_state("openai"), CircuitState::Open);
assert_eq!(cb.get_state("anthropic"), CircuitState::Open);
assert_eq!(cb.get_state("gemini"), CircuitState::Closed);
// Reset openai, anthropic should be unaffected.
cb.record_success("openai");
assert_eq!(cb.get_state("openai"), CircuitState::Closed);
assert_eq!(cb.get_state("anthropic"), CircuitState::Open);
}
}