synaps_cli/
pricing.rs

1//! Centralised pricing logic for Anthropic models.
2//!
3//! All cost calculations live here so that the engine, TUI, and any future
4//! consumer share a single source of truth. Update this file — and only this
5//! file — whenever Anthropic changes its pricing.
6//!
7//! Prices are in USD per million tokens (as of 2026-04).
8//! Source: <https://www.anthropic.com/pricing>
9//!
10//! | Model   | Input  | Output |
11//! |---------|--------|--------|
12//! | Opus    | $5.00  | $25.00 |
13//! | Sonnet  | $3.00  | $15.00 |
14//! | Haiku   | $1.00  | $5.00  |
15//!
16//! Cache pricing (relative to input price):
17//! - Cache reads:    0.10× input price  (prompt-cache hit)
18//! - Cache creation: 1.25× input price  (5-minute TTL write)
19
20/// Returns `(input_price_per_mtok, output_price_per_mtok)` for the given model
21/// string. Matching is substring-based so it works with full model IDs like
22/// `claude-opus-4-5-20251101` as well as short names like `claude-opus`.
23///
24/// Falls back to Sonnet pricing for unknown models.
25#[inline]
26fn model_prices(model: &str) -> (f64, f64) {
27    match model {
28        m if m.contains("opus")   => (5.0, 25.0),
29        m if m.contains("sonnet") => (3.0, 15.0),
30        m if m.contains("haiku")  => (1.0,  5.0),
31        _                         => (3.0, 15.0), // default: Sonnet pricing
32    }
33}
34
35/// Calculate the USD cost of a single model turn.
36///
37/// # Arguments
38/// * `model`           – Model identifier string (e.g. `"claude-sonnet-4-5"`).
39/// * `input_tokens`    – Uncached input tokens billed at full input rate.
40/// * `output_tokens`   – Output / generated tokens (includes adaptive thinking).
41/// * `cache_read`      – Tokens served from the prompt cache (0.10× input rate).
42/// * `cache_creation`  – Tokens written to the prompt cache (1.25× input rate).
43///
44/// # Returns
45/// Cost in USD for this turn.
46pub fn calculate_cost(
47    model: &str,
48    input_tokens: u64,
49    output_tokens: u64,
50    cache_read: u64,
51    cache_creation: u64,
52) -> f64 {
53    let (input_price, output_price) = model_prices(model);
54    (input_tokens    as f64 / 1_000_000.0) * input_price
55        + (cache_read     as f64 / 1_000_000.0) * input_price * 0.1
56        + (cache_creation as f64 / 1_000_000.0) * input_price * 1.25
57        + (output_tokens  as f64 / 1_000_000.0) * output_price
58}
59
60#[cfg(test)]
61mod tests {
62    use super::*;
63
64    #[test]
65    fn opus_pricing() {
66        // 1M input + 1M output, no cache → $5 + $25 = $30
67        let cost = calculate_cost("claude-opus-4-5", 1_000_000, 1_000_000, 0, 0);
68        assert!((cost - 30.0).abs() < 1e-9, "expected $30, got ${cost}");
69    }
70
71    #[test]
72    fn sonnet_pricing() {
73        // 1M input + 1M output → $3 + $15 = $18
74        let cost = calculate_cost("claude-sonnet-4-5", 1_000_000, 1_000_000, 0, 0);
75        assert!((cost - 18.0).abs() < 1e-9, "expected $18, got ${cost}");
76    }
77
78    #[test]
79    fn haiku_pricing() {
80        // 1M input + 1M output → $1 + $5 = $6
81        let cost = calculate_cost("claude-haiku-4-5", 1_000_000, 1_000_000, 0, 0);
82        assert!((cost - 6.0).abs() < 1e-9, "expected $6, got ${cost}");
83    }
84
85    #[test]
86    fn cache_read_bills_at_tenth_input_rate() {
87        // 1M cache-read tokens for Sonnet: 0.1 × $3 = $0.30
88        let cost = calculate_cost("claude-sonnet-4-5", 0, 0, 1_000_000, 0);
89        assert!((cost - 0.30).abs() < 1e-9, "expected $0.30, got ${cost}");
90    }
91
92    #[test]
93    fn cache_creation_bills_at_125_percent_input_rate() {
94        // 1M cache-write tokens for Sonnet: 1.25 × $3 = $3.75
95        let cost = calculate_cost("claude-sonnet-4-5", 0, 0, 0, 1_000_000);
96        assert!((cost - 3.75).abs() < 1e-9, "expected $3.75, got ${cost}");
97    }
98
99    #[test]
100    fn unknown_model_falls_back_to_sonnet() {
101        let cost_unknown = calculate_cost("gpt-99-turbo", 1_000_000, 0, 0, 0);
102        let cost_sonnet  = calculate_cost("claude-sonnet-4-5", 1_000_000, 0, 0, 0);
103        assert!((cost_unknown - cost_sonnet).abs() < 1e-9);
104    }
105
106    #[test]
107    fn zero_usage_is_zero_cost() {
108        assert_eq!(calculate_cost("claude-opus-4-5", 0, 0, 0, 0), 0.0);
109    }
110}
synaps_cli/pricing.rs

synaps_cli/
pricing.rs
