Cost Ledger

Updated Apr 9, 2026

Lexery - Cost Ledger

Tracks estimated and actual spend for wiki maintenance and automation — separate from product Brain inference costs (Portal user traffic, batch jobs, etc.). Pair with Lexery - Maintenance Runbook for when each tier runs.

Provider context: Lexery - Provider Topology. Design for automation: Lexery - Automation Architecture.

Budget envelope

Target: ~$2/month ongoing for second-brain maintenance (Tier 1–2 dominant, Tier 3 occasional).
Spike allowance: one-time build or large restructure months may exceed the envelope; mark rows clearly as non-recurring.

Note: Early "initial wiki" rows below may exceed the monthly target by design. Normalize future months toward the envelope via delta-first Tier 2.

Cost model (maintenance only)

Tier	Use case	Typical tooling	Est. cost / run
Tier 1	Git diff, file hashing, metadata, branch lists	None (local CLI)	$0
Tier 2	Commit digests, PR/issue rollups, short delta summaries	Cheap model via OpenRouter	~$0.001–0.01
Tier 3	Wiki restructuring, merging contradictory pages, net-new canonical docs	Claude Opus-class or equivalent	~$0.10–0.50 / substantial session

Token discipline

Pass diffs and summaries, not whole repos, into Tier 2–3.
Cache file hashes in _system/state/ to skip unchanged large files (see Lexery - Maintenance Runbook).

OpenRouter Model Costs (Product Pipeline)

Хоча ця сторінка фокусується на wiki maintenance, розуміння product pipeline costs важливе для загальної cost awareness. Всі model calls проходять через Lexery - Provider Topology|OpenRouter:

Per-Model Cost Profile

Model	Pipeline Role	Relative Cost	Типовий Use Case
`gpt-5.2`	Premium / legal reasoning	$$$	Lexery - ORCH and Clarification
`gpt-4o-mini`	Classification	$	[[Lexery - U2 Query Profiling
`gpt-5-nano`	Routine	¢	Delta summaries, [[Lexery - Memory and Documents

Daily Cost Drivers

Основні джерела витрат у product pipeline (від найбільших до найменших):

[[Lexery - U10 Writer|U10 Write ($$$) — найдорожчий stage: довгий structured output з legal reasoning, citations, formatting. Кожен write call використовує gpt-5.2 з extended context window
Lexery - U8 Legal Reasoning|U8 Legal Reasoning ($$) — analysis pass перед writing, також на premium model
Lexery - ORCH and Clarification|ORCH decisions ($$) — mid-run orchestration calls; зменшені через Lexery - Retry and Recovery|deterministic canary
Lexery - U2 Query Profiling|U2 Classification ($) — cheap model, але виконується на кожному запиті
Delta summaries (¢) — memory і context updates на gpt-5-nano, мінімальна вартість

ORCH Cost Cutting: Deterministic Canary

Lexery - Retry and Recovery|Deterministic canary — ключовий механізм зменшення витрат. Для straightforward cases (single act, clear article reference) ORCH приймає рішення без дорогого gpt-5.2 call. Ефект: ~50% зменшення mid-run ORCH costs для типових запитів. Детальніше: Lexery - Retry and Recovery.

Brain Maintenance Target

Для wiki і brain-admin automation:

Target: ~$2/month через OpenRouter
Включає: scheduled brain-admin scans (.github/workflows/lldbi-brain-admin.yml), import proposal generation, catalog health checks
Використовує переважно cheap models (gpt-4o-mini, gpt-5-nano) для routine tasks
Expensive model calls тільки для substantive wiki restructuring sessions

Running total

Date	Operation	Tier	Tokens (est.)	Est. cost (USD)	Notes
2026-04-09	Initial wiki build	3	~200k	~2.00	One-time scaffold
2026-04-09	Second brain expansion	3	~300k	~3.00	Large page batch

Reconciliation: When invoice data exists (OpenRouter, Anthropic, Cursor), add a "verified" row or footnote — until then, treat numbers as order-of-magnitude estimates.

Monthly projection

With delta-first processing (weekly Tier 2 + one monthly Tier 3 audit):

Expected steady state: ~$0.50–1.50/month if Tier 2 stays short and Tier 3 is bounded.
Risk drivers: full-repo re-ingest, attaching large PDFs to prompts, repeated multi-hour Opus sessions without checkpointing.

Mitigations

Enforce Lexery - Maintenance Runbook tier boundaries.
Log every paid pass in this table for retroactive budgeting.

Related product costs (out of scope here)

Brain runtime spend (U2/U8/U10/ORCH, embeddings, rerankers) belongs in infra / finance dashboards — link from Lexery - Deployment and Infra when documented. This ledger is wiki ops only.

Governance

Who can add rows? Anyone maintaining the vault; sign with initials in Notes if multi-user later.
Rounding: estimates may be rounded to nearest $0.05 for readability; keep raw notes in monthly Lexery - Log if precision matters.
Cap enforcement: if two consecutive weeks exceed target, switch to Tier 1 only until the next planned Tier 3.

Open questions (cost side)

See Lexery - Unknowns Queue item monthly AI spend (aggregate) — until that is answered, this ledger cannot be reconciled against company-wide burn; it only tracks documented wiki maintenance sessions.