1. 1//! Spend pricing (docs/design/15-reliability.md). Every dollar figure produced
2. 2//! here is an ESTIMATE — providers do not return cost in responses, so
3. 3//! rows are labeled `estimated` and never treated as settled fact.
4. 4
5. 5use crate::PriceEntry;
6. 6use vak_llm::Usage;
7. 7
8. 8/// Rough per-model pricing (USD per million tokens), substring-matched on
9. 9/// lowercase model names. Unknown models are UNKNOWN: callers omit dollar
10. 10/// figures rather than guessing at zero.
11. 11pub fn usd_per_mtok_heuristic(model: &str) -> Option<(f64, f64)> {
12. 12 let m = model.to_ascii_lowercase();
13. 13 let has = |s: &str| m.contains(s);
14. 14 if has("ox-alpha") || has("opencode") {
15. 15 return Some((0.0, 0.0));
16. 16 }
17. 17 if has("opus") {
18. 18 return Some((15.0, 75.0));
19. 19 }
20. 20 if has("sonnet") {
21. 21 return Some((3.0, 15.0));
22. 22 }
23. 23 if has("haiku") {
24. 24 return Some((0.8, 4.0));
25. 25 }
26. 26 if has("4o-mini") || (has("mini") && has("gpt")) {
27. 27 return Some((0.15, 0.6));
28. 28 }
29. 29 if has("gpt-4o") {
30. 30 return Some((2.5, 10.0));
31. 31 }
32. 32 if has("gpt-4-turbo") {
33. 33 return Some((10.0, 30.0));
34. 34 }
35. 35 if has("o3") {
36. 36 return Some((2.0, 8.0));
37. 37 }
38. 38 if has("gemini") && has("flash") {
39. 39 return Some((0.30, 2.5));
40. 40 }
41. 41 if has("gemini") {
42. 42 return Some((1.25, 10.0));
43. 43 }
44. 44 if has("deepseek") {
45. 45 return Some((0.27, 1.1));
46. 46 }
47. 47 None
48. 48}
49. 49
50. 50/// Exact-id overrides win; heuristic substring table is the fallback.
51. 51pub fn resolve_usd_per_mtok(
52. 52 model: &str,
53. 53 overrides: &std::collections::BTreeMap<String, PriceEntry>,
54. 54) -> Option<(f64, f64)> {
55. 55 if let Some(e) = overrides.get(model) {
56. 56 return Some((e.input, e.output));
57. 57 }
58. 58 usd_per_mtok_heuristic(model)
59. 59}
60. 60
61. 61/// Estimated USD for a usage record. Cache-creation tokens bill at the
62. 62/// input rate; cache reads at a tenth of it (provider-typical discount).
63. 63pub fn estimate_cost_usd(
64. 64 model: &str,
65. 65 usage: &Usage,
66. 66 overrides: &std::collections::BTreeMap<String, PriceEntry>,
67. 67) -> Option<f64> {
68. 68 let (i, o) = resolve_usd_per_mtok(model, overrides)?;
69. 69 let fresh_input = usage.input_tokens as f64;
70. 70 let created = usage.cache_creation_input_tokens.unwrap_or(0) as f64;
71. 71 let read = usage.cache_read_input_tokens.unwrap_or(0) as f64;
72. 72 let out = usage.output_tokens as f64;
73. 73 let mtok = 1e6;
74. 74 Some((fresh_input + created) / mtok * i + read / mtok * i * 0.1 + out / mtok * o)
75. 75}
76. 76
77. 77#[cfg(test)]
78. 78#[allow(clippy::unwrap_used, clippy::expect_used)]
79. 79mod tests {
80. 80 use super::*;
81. 81
82. 82 #[test]
83. 83 fn override_beats_heuristic_and_exact_key_wins() {
84. 84 let mut o = std::collections::BTreeMap::new();
85. 85 o.insert(
86. 86 "claude-opus-4-x".to_string(),
87. 87 PriceEntry {
88. 88 input: 1.5,
89. 89 output: 7.5,
90. 90 },
91. 91 );
92. 92 assert_eq!(
93. 93 resolve_usd_per_mtok("claude-opus-4-x", &o),
94. 94 Some((1.5, 7.5))
95. 95 );
96. 96 // Unrelated model falls through to the heuristic.
97. 97 assert_eq!(
98. 98 resolve_usd_per_mtok("claude-sonnet-9", &o),
99. 99 Some((3.0, 15.0))
100. 100 );
101. 101 // Unknown without override stays UNKNOWN.
102. 102 assert_eq!(resolve_usd_per_mtok("totally-novel-model", &o), None);
103. 103 }
104. 104
105. 105 #[test]
106. 106 fn estimate_prices_all_token_classes() {
107. 107 let usage = Usage {
108. 108 input_tokens: 1_000_000,
109. 109 output_tokens: 100_000,
110. 110 cache_creation_input_tokens: Some(500_000),
111. 111 cache_read_input_tokens: Some(2_000_000),
112. 112 prefill_ms: None,
113. 113 load_ms: None,
114. 114 };
115. 115 let usd =
116. 116 estimate_cost_usd("claude-sonnet-4", &usage, &Default::default()).expect("priced");
117. 117 // input 1M*3 + creation 0.5M*3 + read 2M*3*0.1 + out 0.1M*15
118. 118 let expected = 3.0 + 1.5 + 0.6 + 1.5;
119. 119 assert!((usd - expected).abs() < 1e-9, "{usd} vs {expected}");
120. 120 }
121. 121
122. 122 #[test]
123. 123 fn unpriced_model_estimates_nothing() {
124. 124 let u = Usage::default();
125. 125 assert_eq!(estimate_cost_usd("mystery", &u, &Default::default()), None);
126. 126 }
127. 127}
128. 128