How fast do your Claude Code agents run, and who is the session waiting on? Reads your local Claude Code logs, prints speed and time shares. Nothing leaves your machine.

A developer released a Python script that parses local Claude Code session logs (~/.claude/projects/*/*.jsonl) to report how many responses ran in standard versus fast mode, the median end-to-end output speed in tokens per second, and the share of time spent by the model, tools and the human across sessions. The tool reads only timestamps, token counts and the speed field, never message content, and keeps all data on the local machine. It caps tool waits at 5 minutes and human gaps at 1 hour, and computes speed only on responses of 200 or more output tokens.

| | /usr/bin/env python3 | | | """How fast do your Claude Code agents run, and who is the session waiting on? | | | Reads your local Claude Code session logs ~/.claude/projects/ / .jsonl and prints: | | | - how many responses ran at each speed setting standard vs fast mode | | | - the median end-to-end output speed of your responses, in tokens per second | | | - while the agent works on its own: the model's share of the time vs the tools' | | | - across whole sessions: the model's, the tools' and your own share of the clock | | | It reads only timestamps, token counts and the speed field. It never prints or | | | sends message content. Nothing leaves your machine. | | | Usage: | | | python3 claude code speed.py last 30 days, every project | | | python3 claude code speed.py 7 last 7 days | | | python3 claude code speed.py 30 ~/.claude/projects/<one-project-dir | | | How the times are measured, so you can judge the numbers: | | | - Model time: from the message the model answered your prompt or a tool | | | result to the model's last chunk of that answer. It includes the wait for | | | the first token, so the speed is end to end, like Artificial Analysis's. | | | - Tool time: from the model's tool call to the tool's result. Waits over | | | 5 minutes are left out: those are permission prompts or background jobs. | | | - Your time: from the model's answer to your next message, each gap capped at | | | 1 hour, so a night away from the keyboard does not count as thinking. | | | - Speed is computed on responses of 200 output tokens or more, where the | | | first-token wait matters least. Claude Code sends long contexts, so this | | | end-to-end speed runs below the streaming speed a benchmark reports. | | | - Output tokens include thinking tokens. | | | - Resumed and forked sessions copy earlier history into a new log; each | | | message is counted once. | | | - Dollars are what the tokens would cost at Claude Opus 5.5 list prices, | | | whatever model or plan you actually used. Fast mode doubles every price. | | | """ | | | import glob | | | import json | | | import os | | | import sys | | | import time | | | from datetime import datetime | | | TOOL CAP = 300.0 | | | Claude Opus 5.5 list prices, dollars per million tokens, from | | | https://platform.claude.com/docs/en/about-claude/pricing fetched 2026-11-10 : | | | input, cache read, 5-minute cache write, 1-hour cache write, output. | | | Fast mode doubles every one of them https://platform.claude.com/docs/en/build-with-claude/fast-mode . | | | PRICE = 4.00, 0.20, 5.00, 8.00, 20.00 | | | HUMAN CAP = 3600.0 | | | def ts s : | | | return datetime.fromisoformat s.replace "Z", "+00:00" .timestamp | | | SEEN = set | | | SEEN REQ = set | | | def events path : | | | out = | | | for line in open path, errors="ignore" : | | | try: | | | d = json.loads line | | | except ValueError: | | | continue | | | if d.get "isSidechain" or "timestamp" not in d: | | | continue | | | uid = d.get "uuid" | | | if uid in SEEN: | | | continue a resumed or forked session repeats earlier history | | | if uid: | | | SEEN.add uid | | | kind = d.get "type" | | | msg = d.get "message" or {} | | | if kind == "user": | | | c = msg.get "content" | | | if isinstance c, list and any isinstance x, dict and x.get "type" == "tool result" for x in c : | | | who = "tool result" | | | elif d.get "isMeta" or isinstance c, str and c.startswith "<" : | | | who = "meta" | | | else: | | | who = "human" | | | out.append ts d "timestamp" , "user", who, 0, None | | | elif kind == "assistant": | | | u = msg.get "usage" or {} | | | cc = u.get "cache creation" or {} | | | w1h = cc.get "ephemeral 1h input tokens" or 0 | | | w5m = u.get "cache creation input tokens" or 0 - w1h | | | use = u.get "input tokens" or 0, u.get "cache read input tokens" or 0, w5m, w1h | | | ctx = sum use | | | out.append ts d "timestamp" , "assistant", d.get "requestId" , | | | u.get "output tokens" or 0, u.get "speed" , ctx, use | | | out.sort key=lambda e: e 0 | | | return out | | | def main : | | | days = int sys.argv 1 if len sys.argv 1 else 30 | | | root = os.path.expanduser sys.argv 2 if len sys.argv 2 else os.path.expanduser "~/.claude/projects/ " | | | cutoff = time.time - days 86400 | | | files = sorted f for f in glob.glob os.path.join root, " .jsonl" if os.path.getmtime f = cutoff , | | | key=os.path.getmtime | | | model = tool = human = 0.0 | | | sessions = responses = 0 | | | speed setting, speeds, contexts, out tokens = {}, , , 0 | | | tokens in = 0, 0, 0, 0 uncached input, cache reads, 5-minute cache writes, 1-hour cache writes | | | for f in files: | | | ev = events f | | | if not ev: | | | continue | | | sessions += 1 | | | prev, i = None, 0 | | | while i < len ev : | | | t, kind, key, , = ev i | | | if kind == "user": | | | if prev is not None and t = prev: | | | gap = t - prev | | | if key == "tool result" and gap <= TOOL CAP: | | | tool += gap | | | elif key == "human": | | | human += min gap, HUMAN CAP | | | prev, i = t, i + 1 | | | continue | | | j, out, setting, ctx, use = i, 0, ev i 4 | | | while j < len ev and ev j 1 == "assistant" and ev j 2 == key: | | | out = max out, ev j 3 | | | j += 1 | | | end = ev j - 1 0 | | | first = key not in SEEN REQ one request can be logged in more than one piece | | | SEEN REQ.add key | | | if prev is not None and 0 < end - prev < 1800: | | | model += end - prev | | | if first: | | | responses += 1 | | | contexts.append ctx | | | if out = 200: | | | speeds.append out / end - prev | | | if first: | | | out tokens += out | | | for k in range 4 : | | | tokens in k += use k | | | if setting and first: | | | speed setting setting = speed setting.get setting, 0 + 1 | | | prev, i = end, j | | | if not responses: | | | print "No sessions found. Check the path:", root | | | return | | | speeds.sort | | | contexts.sort | | | q = lambda p: speeds int p len speeds - 1 | | | clock = model + tool + human | | | print f"Last {days} days: {sessions} sessions, {responses} model responses" | | | print "Speed setting recorded:", ", ".join f"{k} {v}" for k, v in sorted speed setting.items or "none" | | | print f"Median output speed: {q 0.5 :.0f} tok/s middle half {q 0.25 :.0f} to {q 0.75 :.0f} , " | | | f"over {len speeds } responses of 200+ tokens" | | | print f"While the agent works: model {100 model / model + tool :.0f}% of the time, " | | | f"tools {100 tool / model + tool :.0f}%" | | | print f"Across whole sessions: you {100 human / clock:.0f}%, model {100 model / clock:.0f}%, " | | | f"tools {100 tool / clock:.0f}%" | | | print f"Model time: {model / 3600:.0f} hours, {out tokens / 1e6:.0f}M output tokens, " | | | f"median context {contexts len contexts // 2 / 1000:.0f}K tokens per response" | | | cost = sum t pr for t, pr in zip tokens in, PRICE :4 + out tokens PRICE 4 / 1e6 | | | print f"At Claude Opus 5.5 list prices: ${cost:,.0f} on the standard tier " | | | f" ${out tokens PRICE 4 / 1e6:,.0f} of it output , ${2 cost:,.0f} on fast mode" | | | m share, a share = model / clock, model / model + tool | | | print f"A model 2.5x faster would save about {100 m share 0.6:.0f}% of your session clock, " | | | f"and about {100 a share 0.6:.0f}% of an agent's solo run time, " | | | f"at most {model 0.6 / 3600:.0f} hours of model time fast mode speeds up streaming, " | | | f"not the wait for the first token, so read these as ceilings " | | | if name == " main ": | | | main |