Token Usage VIEW

When: top-N sessions, by-harness totals, or a day rollup from session_token_usage (prefer the VIEW over hand-rolled SUM on messages).

Top sessions

SELECT harness, session_id, input_tokens_total, output_tokens_total, token_grain
FROM session_token_usage
ORDER BY input_tokens_total DESC NULLS LAST
LIMIT 20

By harness

SELECT harness,
       sum(input_tokens_total) AS input_tokens,
       sum(output_tokens_total) AS output_tokens,
       count(*) AS sessions
FROM session_token_usage
GROUP BY harness
ORDER BY input_tokens DESC NULLS LAST

By day

Join sessions for activity time (COALESCE(started_at, source_mtime)):

SELECT date_trunc('day', COALESCE(s.started_at, s.source_mtime)) AS day,
       s.harness,
       sum(t.input_tokens_total) AS input_tokens,
       sum(t.output_tokens_total) AS output_tokens
FROM session_token_usage t
JOIN sessions s
  ON s.harness = t.harness AND s.session_id = t.session_id
WHERE COALESCE(s.started_at, s.source_mtime) IS NOT NULL
GROUP BY 1, 2
ORDER BY 1 DESC, 2

*_total is COALESCE(native, from_messages) — do not also SUM message tokens on top. token_grain is 'session' | 'message' | 'none'.