I Could Measure Claude and Codex Usage. I Still Couldn't Honestly Assign It to a Task.

Once you use Claude Code or Codex for real work, a total usage number stops being enough. You want to know which change consumed it. I did not build agent-cost because I had missed the existing token and cost trackers. I knew about multi-agent reporting CLIs, local dashboards, and OpenTelemetry-style observability stacks. I had even built a similar view in Notion before. The problem appeared when I tried to use that kind of reporting in an operational workflow. I needed agent logs to stay on the machine. I wanted a small runtime dependency surface, custom metrics I could audit, and a machine-readable result that another tool could consume. Most importantly, I needed session measurement and task attribution to remain two different claims. I did not need another universal dashboard. I needed a boundary underneath the dashboard that could answer: is this number supported well enough to enter task accounting? A measurement layer below the UI Different tools optimize for different jobs. A broad CLI such as ccusage is useful when coverage across agents matters. Local interfaces such as token-tracker or AgentMeter are a better fit for visual exploration of projects, sessions, subagents, and tools. An OpenTelemetry stack is the natural choice for fleet-level metrics, logs, and traces. Those are not inferior versions of agent-cost . They serve different use cases and trust models. The layer I wanted looked like this: local observations -> auditable normalized facts -> explicit pricing status -> caller-selected sessions -> task-attribution policy -> optional dashboard / Notion / spec-lane agent-cost reads logs that Claude Code and Codex CLI have already written locally. It normalizes each usage event into a fact with a model, token kind, timestamp, and count. At runtime it makes no network calls and declares no Python runtime dependencies. Its price catalog has a version and SHA-256 digest, both carried into machine-readable output. That “zero-network” claim is deliberately l