How much work does one coding session, and one request, contain?
Computes the count distributions behind tab:session_internal_counts
(src/04_SessionContext.tex): requests, user-/tool-initiated steps, and tool calls per
session; tool-initiated steps and tool calls per request; and tool calls per step — each as
avg / p25 / p50 / p90 / p99.
Per session
| Metric | Avg | P25 | P50 | P90 | P99 |
|---|---|---|---|---|---|
| Requests | 9.2 | 1 | 1 | 18 | 137 |
| User-initiated steps† | 8.9 | 1 | 1 | 17 | 129 |
| Tool-initiated steps | 73.6 | 4 | 15 | 135 | 1,107 |
| Tool calls | 101.4 | 8 | 25 | 176 | 1,438 |
Per request
| Metric | Avg | P25 | P50 | P90 | P99 |
|---|---|---|---|---|---|
| User-initiated steps | 0.9 | 1 | 1 | 1 | 1 |
| Tool-initiated steps | 7.8 | 0 | 1 | 20 | 86 |
| Tool calls | 10.8 | 0 | 2 | 30 | 113 |
Per step
| Metric | Avg | P25 | P50 | P90 | P99 |
|---|---|---|---|---|---|
| Tool calls | 1.2 | 1 | 1 | 2 | 4 |
Coding sessions are persistent and overwhelmingly autonomous (the paper’s
tab:session_internal_counts). A session averages 9.2 requests but with a long tail (p99 = 137),
so the human keeps coming back to the same session over and over. Per session there are far more
tool-initiated steps (avg 73.6) than user-initiated ones (avg 8.9), so once a request lands the
loop runs itself: resolving one request takes ~8 tool-initiated steps and ~11 tool calls on
average. At the step level each round issues just over one tool call (avg 1.2, p50 1, p90 2), so
parallel tool calling does happen but is the exception, not the norm.
# default merged trace (materialized to a temp DuckDB cache on first use)
uv run python artifacts/session/session_internal_counts/analyze.py
# the pinned public trace
uv run python artifacts/session/session_internal_counts/analyze.py -i trace/syfi_coding_trace.jsonl
# a prebuilt DB, into a chosen dir
uv run python artifacts/session/session_internal_counts/analyze.py --db /tmp/trace.duckdb -o /tmp/out
session_internal_counts.tex — the merged three-line (booktabs) table, ready to \input or
paste into src/04_SessionContext.tex.session_internal_counts.md — GFM Markdown mirror of the table, rendered on the web detail page.headline.json — the few headline numbers for the Overview gallery card.No figures.