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Gemini 4 Carbon is 4x cheaper per token than Fable 5.2. On a real bug it cost 2.5x more per try.
I gave them and Opus 5.5 a real fastify bug: the whole repo and the bug report, no hints. Two tries each.
What one working fix cost:
Fable 5.2: $0.90
Gemini 4 Carbon: $2.29
Opus 5.5: no working fix, $1.28 spent
Carbon took about six times as many steps as Fable. Google's own launch post says it spends more tokens exploring and verifying. Cheap tokens, just a lot of them.
And $2/$10 is the intro price. At the announced $4/$20, the same fix would cost Carbon about $4.60.
Opus had its own surprise: it reported "2,637 passed, 0 failed" on a broken fix.
The price per token is what you see on the pricing page. The steps are what ends up on the bill.
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Setup: pre-fix repo + bug report, same tools for every model (read, search, edit, run commands), no internet.
A fix counts only if the test the maintainers added with their fix passes.
Per try: Fable $0.43-0.47, Carbon $1.07-1.22, Opus $0.63-0.65.
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Qoduck, the free mystery model in Qoder, fixed real bugs in 15 of 21 tries for $0. Nobody will say who made it. People are guessing Qwen 4.
7 bugs, 3 tries each, judged by the maintainers' own tests.
The answers came in three kinds:
→ exactly right. marked (Markdown to HTML) crashed when a plugin was named "constructor". The model wrote the same one-line fix the maintainers merged
→ right idea, new side effect. axios timed requests with the system clock, which can break a Next.js build. The model switched to a stopwatch timer, but that timer returns fractions, and axios reports whole milliseconds
→ confidently wrong. fastify rejected every request when its header rules came from a shared schema. Twice the model explained the cause in detail, and the request from the bug report was still rejected
So I added one line to the fastify prompt: turn the bug report's example into a test and walk it through your fix.
It fixed the reported bug 3 times out of 3, up from 1. And all 3 times it broke the case right next to it, the one I never mentioned.
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Setup: 7 bugs (axios, hono, immer, marked x2, fastify, mobx), bug report + the file, new chat per run, Qoder app, default thinking.
Terms: docs.qoder.com/events/qoduck…
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Setup: 7 bugs (axios, hono, immer, marked x2, fastify, mobx), bug report + the file, new chat per run, Qoder app, default thinking.
Terms: docs.qoder.com/events/qoduck…
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One click in Claude Code and my test password was one commit away from GitHub.
The Claude Code team says leaked files like this were added to git by hand. I never touched mine.
The click was "Yes, and don't ask again". It saves the command you approve into a project file, passwords included. Apiiro found 1,122 of these files with real secrets on public GitHub.
what I did:
→ a curl with a test password, approved with "don't ask again"
→ Claude Code saved it to .claude/settings.local.json
→ the folder wasn't a repo yet, so no auto gitignore
→ git init, git add . and the password was staged
same click in a folder that was already a repo:
→ the password still went into the file
→ Claude Code added the file to my global gitignore, git skipped it
same password in .env:
→ Claude Code used $STAGING_PASSWORD instead
→ the password never showed up in the command
→ "don't ask again" wasn't even offered
In my runs the leak needed two things: a password typed into the chat, and a folder that became a repo later
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Fake password, Claude Code 2.1.319. To see if the file was ever in your git history, run this in the repo root:
git log --all --oneline -- .claude/settings.local.json
The team's reply on HN: news.ycombinator.com/item?id…
Apiiro's report: apiiro.com/blog/coding-agent…
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On tasks a cheap model already failed, the next model succeeds about half as often as it usually does. My old routing was built on exactly that handoff.
That's from Route Anything, a new NUS and Berkeley study with 374,401 scored runs. The drop showed up in all 42 model pairs they tested. Half is the median.
What paid off was sorting tasks before the first call. On their coding benchmark that router never once called Opus 4.6, got 25.5x Opus's score per dollar and lost under half a point.
Sending everything to the cheapest model, Qwen3-Max, got 20.1x but dropped 4.2 points.
And on wall-clock time, plain Opus beat every cheap-model-plus-checker chain. It simply answered faster.
Paper ↓
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The Claude Code tip "Sonnet writes, Haiku searches, Opus advises" does save 60%. But only without the Opus part. With Opus advising, my bill went up 2.2x.
Same bug, 3 runs per setup, every fix passed tests the model never saw. Cost of one fix:
- default, Opus does everything: $0.58, 89 s
- the tip with the usual settings: $0.41, 164 s. Haiku never searched, Opus never advised. Just Sonnet
- all three models actually working: $1.30, 389 s. Opus advising alone was $0.78 of it
- Sonnet writes, Haiku searches, no Opus: $0.23, 154 s
The cheapest setup wasn't the fastest. Opus alone finished in 89 s.
What finally got Haiku searching, for 2-3 cents a fix:
CLAUDE_CODE_SUBAGENT_MODEL=haiku CLAUDE_CODE_SUBAGENT_MODEL_FORCE=1 claude --model sonnet
plus one line in the prompt: "use the Explore subagent for searching". Without FORCE, the Haiku setting doesn't reach the built-in search agent.
Setup details and why the advisor costs so much ↓
"Usual settings" = --model sonnet --advisor opus + CLAUDE_CODE_SUBAGENT_MODEL=haiku.
The bug: one character in hono's URL decoding, reported only by its symptom, plus a check of the rest of the codebase. Hidden tests scored every fix.
Claude Code 2.1.319, API prices from claude.com/pricing. FORCE also moves custom subagents to Haiku, even ones with their own model set. One task, 3 runs each, so treat it as one data point.
Why the advisor eats the bill: xitter.twitterapi.xyz/od_chenko/status/21176…
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On a bug that needed one line, Kimi K3.1 Pro wrote one line. Opus 5.5 wrote over 30. Every time.
I gave both 4 real bugs that were just fixed in popular JavaScript libraries: axios, Hono, Immer and marked. 3 tries each. Both fixed nearly everything. They just work very differently.
Kimi changes as little as it can. On 2 of the 4 bugs its fix was basically the one the maintainers merged.
Opus fixes the bug and keeps going. Sometimes that helps: on Hono, in 2 of 3 tries, it also made the compiler catch the same mistake before the code even runs. Sometimes it's noise: on marked it added two helper functions to a one-line fix.
On axios Opus also added a backup for unusual setups, like the real fix did. Kimi didn't. Your app probably doesn't need it. A library like axios does.
Kimi codes like the maintainer. Opus codes like a careful new hire.
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One line in CLAUDE.md turned a 9-cent Claude Code bug fix into a 50-cent one.
The line tells Sonnet to consult the /advisor. Every call has Opus re-read the whole session, no cache, full price.
Opus on its own did the same fix for 19 cents. And without the rule, Sonnet never asked once.
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From December, Codex and your ChatGPT chats come out of one allowance.
OpenAI is putting Plus, Pro and Business on a single token budget for both. Instant chat stays outside it, everything else draws from the same pool.
OpenAI expects most people won't wait for resets more often than now. What it hasn't said is how big the pool is on each plan. Until it does, there's no way to tell if a heavy Codex day leaves room for the evening's chats.
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DeepSeek's new agent runs commands as you without a word, and only speaks up when it's genuinely unsure.
That design has a price. 23 million tokens a run, up to four times a normal session, by their own test, and the speedup mostly shows up on your worst days, not your average one.
It also has a blind spot. A bad instruction doesn't read as uncertainty, so the agent stays quiet and just runs it, as you, straight into your home directory. Their own docs say it plain: blocked commands are not a security boundary.
So the one run you'd want it to pause on is the one it stays quiet for.
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A perfect transcript can still miss the whole call.
Nemotron 3.5 Transcribe just hit #1 on Voice Arena, 32.43% cpWER and the fewest dropped words on the board. Reading the words is basically solved.
The voice agents I saw rarely broke on a wrong word. They broke on tone. Someone says "that's fine" in a voice that means the opposite, the agent only gets the text, and it believes them.
A better transcriber doesn't fix that. It just transcribes the flat version faster. Models that hear the mood exist now, but they cost you the clean transcript most teams still build on.
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Benchmark and the full numbers: Voice Arena's Nemotron 3.5 Transcribe results.
xitter.twitterapi.xyz/voicearena_ai/status/2…
🏆 NVIDIA Nemotron 3.5 Transcribe debuts at #1 among 14 systems on Voice Arena’s Diarization + ASR leaderboard.
Across the full benchmark, it achieves 32.43% cpWER.
This track tests whether a system can get both the words and the speakers right. We evaluated 139 held-out conversations with 2-8 speakers across in-person and online settings, including overlapping speech.
Nemotron 3.5 Transcribe is first in both settings: 34.08% cpWER in person (far field) and 22.13% on online calls.
It has the lowest word deletion rate on the leaderboard. Deletions are 8.32% of reference words, against a median near 31%.
Congratulations to @NVIDIAAI on the release ! 👏
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