forked from bai/curriculum-project-hub
hongjr03
f3b087371a
Replace the single-scalar cost model on AgentRun with an append-only UsageFact ledger. One AgentRun owns zero or more UsageFact rows; each records one billable consumption event (model completion, external capability, or tool proxy) with its own provider/model/tokens/quantity/ cost. AgentRun.costUsd/inputTokens/outputTokens become a derived rollup cache. This unblocks external capabilities (PDF->MD bundle, audio/video->text) that bill in non-token units (pages, seconds) through a different provider than the main agent loop, without per-capability schema changes or nested AgentRuns (which would pollute lock/admission/session semantics). Contract: - spec/Spec/System/Agent/Usage.lean pins UsageFact, UsageFactKind, CostSource and three invariants: append-only; belongs to one run, never holds a lock; missing cost != zero (ADR-0022). - ADR-0026 records the decision, the rejected nested-Run alternative, the rollup cache strategy, and the deferred capability registry / pricebook / post-hoc correction flows. Schema: - UsageFact model with indexes on (runId, occurredAt), (runId, kind), (provider, model, occurredAt), (capabilityId, occurredAt). - Migration backfills one synthetic model_completion fact per existing run with recorded cost/tokens (correlationId = runId marks backfill); truly unrecorded runs stay runsWithoutCost per ADR-0022. Write path (trigger finish): - Write the UsageFact first, then mirror it onto AgentRun as two separate statements (not one transaction). The fact is the truth so it goes first; the cache is derived so it goes second. A crash between them leaves the cache stale but the usage service re-reads facts directly, so this is recoverable; the reverse order would lose the truth. Separate statements also avoid an AgentRun row lock held across the insert's FK ShareLock, which deadlocked concurrent workspace teardown under the Organization->Project->AgentRun->UsageFact cascade. Read paths: - org/usage.ts aggregates from UsageFact, ignoring the AgentRun cache. - slash /usage buckets by (fact.provider, fact.model); a run with a main loop + an external call lands in two buckets. - session detail exposes usageFacts[] + costSource for future per-run cost-breakdown UI. Tests: - usage.test.ts: 6 integration tests pin fact aggregation, missing-cost- !=-zero, multi-fact-per-run, empty-run, project-level, empty-org. - trigger.test.ts: existing /usage assertion ($0.0023, openrouter / mock-model) passes on the fact path. - feishu-reactions mock prisma gains usageFact.create.