fix(metrics): price OpenRouter stealth previews as a real $0

CHANGELOG.md

@@ -6,6 +6,10 @@ All notable changes to `@tangle-network/agent-eval` and its sibling `agent-eval-
 
 ## Unreleased
 
+### Fixed
+
+- Price OpenRouter stealth previews (`stealth/*`) as a real $0 so the DSPy RLM budget ledger admits them instead of refusing an unpriced model.
+
 ## [0.182.0] — 2026-09-15
 
 ### Breaking

src/analyst/benchmark-implementation.ts

@@ -139,7 +139,7 @@ export const ANALYST_BENCHMARK_IMPLEMENTATION_FILES = Object.freeze([
 ])
 
 export const ANALYST_BENCHMARK_IMPLEMENTATION_SHA256 =
-  '53b4c9f453ed05e46968ed39a8e365f8593163b264c0b1a770f7781005d3aae7'
+  '956a7205aae4110a7b3dd927bef2c1098986e16cd89a17276791083219ade3fc'
 
 export function analystBenchmarkImplementationDigest() {
   return ANALYST_BENCHMARK_IMPLEMENTATION_SHA256

src/metrics.ts

@@ -25,6 +25,10 @@ export const MODEL_PRICING: Record<string, TokenPrice> = {
  *  none of which appear in the exact table above — without this they priced
  *  to a silent $0, blanking every cost/Pareto axis downstream. */
 const FAMILY_PRICING: Array<[RegExp, TokenPrice]> = [
+  // OpenRouter stealth previews (`stealth/union-alpha`, …) bill $0 during
+  // their preview window. A real zero row lets the budget ledger admit them;
+  // an unpriced id is refused before the first call.
+  [/^stealth\//, { input: 0, output: 0 }],
   [/claude.*opus/, { input: 0.015, output: 0.075 }],
   [/claude.*haiku/, { input: 0.0008, output: 0.004 }],
   [/claude.*sonnet|claude-code|claude-sonnet/, { input: 0.003, output: 0.015 }],

tests/metrics-pricing.test.ts

@@ -26,6 +26,13 @@ describe('estimateCost — real harness/router model ids price non-zero', () =>
     })
   }
 
+  it('prices OpenRouter stealth previews as a real $0, not unpriced', () => {
+    expect(isModelPriced('stealth/union-alpha')).toBe(true)
+    expect(resolveModelPricing('stealth/union-alpha')).toEqual({ input: 0, output: 0 })
+    expect(estimateCost(1000, 1000, 'stealth/union-alpha')).toBe(0)
+    expect(isModelPriced('union-alpha')).toBe(false)
+  })
+
   it('still prices the exact legacy table entries', () => {
     expect(estimateCost(1000, 1000, 'gpt-4o')).toBeCloseTo(0.0125, 6)
   })