RELIABILITY TRACKER · P2 OPEN

Reasoning Tokens Omitted from Usage-Cost Estimates · Issue #68081

A source-linked review of a reported Hermes Agent usage-accounting defect where reasoning tokens are captured during normalization but omitted from estimated per-call and downstream cost calculations.

Issue brief · July 20, 2026 · NousResearch/hermes-agent · Issue #68081

What the report describes

The report says normalize_usage() captures reasoning tokens, while estimate_usage_cost() prices only input, output, and cache tokens. The issue documents DeepSeek and OpenRouter reproductions in which per-call estimates materially undercounted spending and Langfuse inherited the same estimate. Exact impact depends on provider pricing, workload, and the accuracy of the reported token fields.

Scope note: This page summarizes a linked open issue, not an independent billing determination. Provider invoices and current pricing documentation remain the authoritative source for actual charges.

Verification matrix

SignalWhat to inspectSafe review response
Usage captureWhether normalized usage records include reasoning-token fields and preserve provider unitsRetain raw usage and provider identifiers for reconciliation.
Pricing pathWhether cost estimation includes every billable token category for the selected providerMap pricing logic explicitly to the provider usage schema and pricing version.
Per-call reconciliationCompare agent estimate with provider-visible billable usage for controlled callsReport any difference with the request date, model, price source, and methodology.
Downstream telemetryWhether observability or cost dashboards reuse the same incomplete estimateTrace derived metrics so an upstream accounting omission is not mistaken for independent confirmation.
Budget guardrailsWhether alerts or project budgets rely on undercounted valuesUse conservative thresholds or provider reconciliation until the estimate is corrected.

Reproduction and monitoring protocol

  1. Choose controlled requests that expose input, output, cache, and reasoning-token fields where supported.
  2. Record the model, provider price reference, timestamp, and normalized usage payload.
  3. Calculate a transparent expected estimate from all billable categories and compare it with the displayed estimate.
  4. Trace whether downstream cost reporting consumes the same estimate.
  5. Re-test after an upstream fix before relying on project-level budget or attribution figures.

Source evidence

NousResearch/hermes-agent · Issue #68081

Verify current issue state, labels, affected versions, and remediation before making a deployment, security, or budgeting decision.