Wire cost accounting through to persistence and CLI

[rogue-socket]

Summary

Token usage is captured during agent strategy execution and persisted to SQLite, but USD cost is calculated in-memory by LLMClient and lost when the process exits. CLI inspect recalculates cost at display time from stored tokens + pricing config — meaning cost is never a first-class persisted artifact.

Current Data Flow (with 6 break points)

Provider API → Adapter extracts usage dict → LLMResponse.usage
  → LLMClient._record_usage_and_enforce_post_call_limits()
    → Calculates cost_usd via _estimate_cost_usd() (lines 308-330)
    → Stores in self._run_usage[run_id]["cost_usd"]  ← IN-MEMORY ONLY (BREAK 1)
  → Strategy._aggregate_usage(turns)  ← aggregates TOKENS only, ignores cost (BREAK 5)
  → AgentResult.token_usage = aggregated tokens
  → Executor: execution.token_usage = agent_result.token_usage  ← NO cost_usd field (BREAK 2-3)
  → Storage: steps.token_usage_json column  ← EXISTS, persisted correctly
  → Storage: steps.cost_usd column  ← DOES NOT EXIST (BREAK 4)
  → CLI inspect: recalculates cost from tokens + pricing config at display time

What's Persisted Today

• token_usage_json (per step) — in SQLite steps table, line 234 of storage/sqlite.py
• model_name (per step) — in SQLite steps table

What's Lost

• LLMClient._run_usage[run_id]["cost_usd"] — calculated per-request with _estimate_cost_usd() using pricing_usd_per_1k_tokens config
• Per-step cost breakdown
• Run-level total cost

Key Code Locations

Component	File	Lines	Status
Cost calculation	llm/client.py	308-330	_estimate_cost_usd() — working, in-memory only
Usage recording	llm/client.py	246-281	_record_usage_and_enforce_post_call_limits() — stores to _run_usage dict
Token aggregation	agent/strategies.py	248-256	_aggregate_usage() — sums tokens, ignores cost
StepExecution model	core.py	191-214	Has token_usage field, NO cost_usd field
SQLite steps schema	storage/sqlite.py	214-239	Has token_usage_json column, NO cost_usd column
CLI inspect display	cli.py	3480-3526	Recalculates cost from tokens + pricing at display time
CLI cost estimator	cli.py	271-297	_estimate_step_cost_usd() — display-time recalculation

Implementation Path

1. Add cost_usd: Optional[float] = None field to StepExecution dataclass (core.py:211)
2. Add cost_usd column to SQLite steps table (storage/sqlite.py:234)
3. Update storage.append_step() to persist cost
4. Pass cost from LLMClient response through AgentResult to Executor._dispatch_agent()
5. Add run-level cost aggregation field to Run model
6. Update CLI inspect to display persisted cost instead of recalculating

Priority

Tier 1 — High Impact, Low Effort. The data is already captured; it needs ~6 touch points to wire through to persistence.

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