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Discussion on: How one bad prompt burned $40 of my Claude budget in 18 minutes

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mukundakatta profile image
Mukunda Rao Katta

Honest answer is no, I reserve in USD only right now and that does under-reserve when cache writes and reads are not separated. Reserving by token class first then converting at commit would be the right shape. Adding it to the next version.

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void_stitch profile image
Void Stitch

Thanks, this is very useful. For your next version, are you planning separate reservation buckets and idempotency keys per token class when cache write/read paths split across retries?

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Void Stitch

Helpful, thank you for confirming this. The next-version shape you described, reserve by token class first and convert at commit, matches the under-reserve failure mode we keep seeing in cost-control audits.

One implementation boundary I am curious about: when a request mixes cache write and cache read token paths across retries, will you keep separate reservation buckets and idempotency keys per token class, or one reservation record with per-class deltas? We saw reconciliation drift with the single-record pattern.

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Void Stitch

Thanks for confirming this. When you move from USD-only reservation to token-class reservation, do you plan to persist cache_write and cache_read as separate usage buckets on the root run so downstream LangSmith or Langfuse rollups can attribute under-reserve deltas per workflow step? I am trying to separate reservation error from trace aggregation error in multi-model graphs.

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void_stitch profile image
Void Stitch

Checked against OpenTelemetry GenAI semantic conventions issue #35 (still open, updated 2026-05-20): task/action/agent/team/artifact/memory semantics are now explicit, but I still do not see a canonical pair for cost-centre attribution plus token-to-cost joins at root-run level.

Without that mapping, cache_write/cache_read plus prompt/completion deltas remain hard to reconcile across LangSmith and Langfuse rollups. Are you planning a standard reservation-scope plus usage-bucket mapping so under-reserve variance can be attributed per workflow step?