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October 20, 2026

The Diff No. 017: For weeks a free model called Space Bunny quietly burned through 200 trillion tokens. This morning it got a name.

For weeks a free model called Space Bunny quietly burned through 200 trillion tokens. This morning it got a name, and Hacker News got suspicious. Plus the quiet ones nobody talks about.
View in browser: The Diff No. 017
The Diff  No. 017
Tuesday, 20 October 2026  ·  AI dev news, only what is verified
whatmodel.sh share card
For weeks a free model called Space Bunny quietly burned through 200 trillion tokens. This morning it got a name, and Hacker News got suspicious.

Three launches in four days, all priced like a rounding error, all with benchmark tables, and a front-page thread full of people asking who checks them. Plus: a 209M-parameter forecaster that runs on a laptop CPU, a diffusion LLM that claims 1,000+ tokens a second, and a Google Research harness that rewrites itself between tries.

Today: Space Bunny unmasked, Mistral’s time-series model, Mercury 3, recursive harnessing, a site that audits the labs’ own scores, and the Meta engineer who said what everyone was thinking.

Every lab says it is first and cheapest. The interesting question this week is who checks.

IN THIS ISSUE
01
🐰 Space Bunny gets a name
MiniMax M3.1 Flash: the mystery model from OpenCode Go is official, cheap, and already being called benchmaxed.
02
📈 A forecaster that fits on your CPU
Mistral Timestral: four time-series models, 5M to 209M parameters, zero-shot, with covariates.
03
⚡ A language model that drafts in parallel
Mercury 3 from Inception: a diffusion LLM claiming 1,068 tokens a second, 1M context and $0.20/$0.70 pricing.
04
🔁 Agents that rewrite their own harness
Harness²: Google Research code that proposes, probes and composes edits to an agent’s prompts, tools and memory, with weights fixed.
05
🧾 Do the labs inflate their own scores?
whatmodel.sh matches 611 lab-reported scores against independent measurements and prints the gap.
06
😬 The Meta engineer and the black box
An Ask HN about shipping AI-written code you do not understand drew 130 replies. The answers are practical.
🔥 VIRAL
The loud ones on Hacker News. Numbers are a morning snapshot.
MiniMax M3.1 Flash announcement graphic
01  HN: 402 points · MiniMax blog, Oct 19 · image: MiniMax

🐰 Space Bunny gets a name

MiniMax M3.1 Flash: the mystery model from OpenCode Go is official, cheap, and already being called benchmaxed.
SCENE

For a while, people using OpenCode Go got a free model called "Space Bunny." Nobody was told what it was. This morning MiniMax said it was an early version of M3.1 Flash and that it had processed more than 200 trillion tokens while anonymous. On Hacker News, a commenter called DCKing was unimpressed: it was served free for a while, they wrote, and "failed to impress anyone as far as I can tell." Another, mawadev, asked the question under the whole thread: is anyone independently verifying any of this?

THE THING

MiniMax’s own numbers: 73.7% on DeepSWE v1.1, 61.7 on OSWorld V2, 82% on CyberGym, 200+ output tokens a second (median 170+), and a flat $0.15 per million input tokens, $0.60 output, $0.015 cached input. They say that is 70% cheaper than the previous model for agentic tasks. All of that is the vendor’s table, run by the vendor. The post says the model is on the MiniMax API, M Plan and MiniMax Code, and that weights "will be released later," with no date.

✂️ STEAL IT

The stealth-model trick is the useful part. A free anonymous model gives a lab real usage data with no brand bias, and gives you a free taste test. If your coding tool offers an unnamed model, you can run your own ten tasks against it before you know whose it is.

Watch  VERDICT

Weights are promised, not shipped, and the one commenter who used it as Space Bunny was cold on it. If you want to try, the price is low enough to spend a few dollars on your own tasks. It fails you if you pick it off the vendor table instead of off your own repo.

MiniMax announcement  ·  HN discussion

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Mistral Timestral announcement image
02  HN: 563 points · Mistral blog, Oct 15 · repo Apache-2.0 · image: Mistral

📈 A forecaster that fits on your CPU

Mistral Timestral: four time-series models, 5M to 209M parameters, zero-shot, with covariates.
SCENE

A commenter on the Timestral thread, logancbrown, put the real use case plainly: you could train an XGBoost model on one series with holiday covariates, but what if you have 10,000 different series to forecast? Ten thousand separate models each have little history. One generic model has to cope with everything. That gap is where a pre-trained forecaster is supposed to help. Another commenter, davedx, said they were migrating their macro team to it. Others, like beernet, called the whole idea marketing and noted Mistral’s post has an imaginary customer, not a real one.

THE THING

Mistral says its largest model, 209M parameters, ranks first on three public forecasting benchmarks, GIFT-Eval, TIME and fev-bench, among pre-trained zero-shot models, from a single checkpoint with no ensembling. The family has four sizes. It handles multivariate series and both past and known-future covariates (production schedules, weather forecasts). Mistral’s CPU numbers: on 8 threads, forecasting one day ahead from three weeks of 15-minute history takes 10 ms with the 5M model and 140 ms with the 209M one. Those are Mistral’s measurements. The mistralai/timestral repo, created October 15, had 582 stars and an Apache-2.0 license on the repository this morning. We read the post and the repo page; we ran nothing.

✂️ STEAL IT

Time series is the least glamorous data in most companies: metrics, sensors, queues, cost. A model you can run on a CPU next to the data is a different proposition from another chat model.

Try today  VERDICT

If you have a pile of related series (capacity, traffic, spend), run Timestral zero-shot against your last month and compare to whatever you use now, a naive baseline included. It fails if your series are unusual or short on structure; leaderboard wins are not your data.

Mistral announcement  ·  The repository  ·  HN discussion

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Inception Mercury 3 announcement image
03  HN: 226 points · Inception blog, Oct 15 · image: Inception

⚡ A language model that drafts in parallel

Mercury 3 from Inception: a diffusion LLM claiming 1,068 tokens a second, 1M context and $0.20/$0.70 pricing.
SCENE

Inception’s co-founder and chief scientist, Volodymyr, showed up in the HN thread himself as volodia: Mercury 3 is "our most capable production diffusion LLM." Simon Willison, in the same thread, wondered why Google did "effectively nothing" with last year’s Gemini Diffusion demo, then drew pelicans with it through OpenRouter and the Inception API and called them "a little quirky."

THE THING

A diffusion LLM refines a whole draft in parallel instead of writing one token at a time. Inception says Mercury 3 outperforms GPT-6 Luna and Claude Haiku 5.5 on a range of benchmarks at matched reasoning effort, runs 1,000+ tokens a second (1,068 on NVIDIA Blackwell, in their words) which is 4 to 8 times faster, and holds 1M tokens of context, up from 260K. Price: $0.20 per million input and $0.70 per million output, with 50% off at launch. All speed and quality claims are Inception’s own. Simon’s pelicans are the only independent output in the thread, and they are an SVG toy, not an eval.

✂️ STEAL IT

Speed changes what you build. At a thousand tokens a second, an agent can retry five times in the time a normal model writes one answer. That is a design choice, not a benchmark.

Watch  VERDICT

Interesting where latency is the product: voice, autocomplete, tight agent loops. It fails if "on par with small frontier models" is not enough for your task, and nobody outside Inception has published a head-to-head we could find this morning.

Inception announcement  ·  HN discussion

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🔭 UNDER THE RADAR
Quiet tools and field reports worth your time.
google-research/harness2 repository card
04  GitHub: 12.3k stars · repo created Oct 6 · arXiv Oct 9 · Apache-2.0 · card: GitHub

🔁 Agents that rewrite their own harness

Harness²: Google Research code that proposes, probes and composes edits to an agent’s prompts, tools and memory, with weights fixed.
SCENE

Picture the part of agent work nobody likes: you tune the system prompt, the tool descriptions and the memory rules by hand, run the agent, squint at transcripts, and edit again. A group led by Ruiyao Xu, with Chen-Yu Lee and others, published code under google-research that tries to do that loop automatically, on tasks it has never seen, without a ground-truth checker.

THE THING

The paper calls it recursive harnessing. Task-level recursion runs a Propose, Probe, Compose step: a harness editor proposes edits, candidates are tried on the same task, and a composer builds a refined harness from the contrast between runs. A second level keeps a persistent improvement harness that learns from each task. It edits eight components: system prompt, guardrails, memory, tool guidance, subagents, skills, scripts and plugins. The authors report that one step improves GLM-5 and Gemini 3.5 Flash on three professional benchmarks, by up to 11.5 points on WorkBuddy-Bench, 4.5 on JobBench and 11.8 percentage points on LAB partial pass rate. Those are the authors’ numbers on their chosen benchmarks. The repo supports OpenCode and Codex as executors.

✂️ STEAL IT

Steal the contrast trick: when you tune a prompt, compare two runs of the same task and ask what differed in behaviour, instead of reading one transcript. It works on paper with no framework at all.

Try today  VERDICT

The README promises a local demo that needs no model credentials: Linux, Python 3.12, uv, then harness2-demo --output runs/demo --k 2. We did not run it. The real benchmarks need model access and more setup. It fails you if your tasks have a checker you could use directly; then plain optimisation is simpler.

The repository  ·  The paper (arXiv)

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whatmodel.sh share card
05  whatmodel.sh/claims · read Oct 20 · card: whatmodel.sh

🧾 Do the labs inflate their own scores?

whatmodel.sh matches 611 lab-reported scores against independent measurements and prints the gap.
SCENE

Someone got tired of the same question the MiniMax thread asked. They collected every case where a lab published a score and someone independent, a leaderboard, a paper or another lab, measured the same model on the same test, and put the result on one page with a dot for each pair. The site is whatmodel.sh. It is one page and the method is printed on it.

THE THING

By its own count: 611 pairs, 180 models, 103 tests. Lab scores are 6.4% higher on average, with a median gap of 1.2% and a 95% interval of 3.8% to 9.5% for the mean. When the numbers differ, the lab’s is higher 63% of the time: 375 lab higher, 216 independent higher, 20 ties. The gap depends on the test. Fixed-format tests like MMLU, WinoGrande, ARC and HumanEval barely move. Tests where the setup is part of the result, like the agent harness on SWE-bench Verified or the sampling budget on AIME, show the biggest gaps. We did not recompute any of this.

✂️ STEAL IT

Read it as a prior, not a verdict. If a launch table is mostly agent-harness benchmarks, discount it more than if it is mostly fixed-format ones.

Try today  VERDICT

Five minutes with the page changes how you read launch tables. It fails as a precise tool: it only covers pairs where an independent number exists, and it is one site’s collection.

whatmodel.sh/claims

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parthh01/sphinx repository card
06  Ask HN: 298 points · 130 comments · Oct 19

😬 The Meta engineer and the black box

An Ask HN about shipping AI-written code you do not understand drew 130 replies. The answers are practical.
SCENE

A user posting as rzk quoted a LinkedIn post from a Meta engineer: "I never felt this uncomfortable doing my job." The code feels like a black box, checking every line would take forever, and the engineer asks how much understanding is enough. The Ask HN got 298 points. It is not a launch, which is why it is here.

THE THING

Three answers stood out. bitwizeshift: do not let the model design, let it implement a design you drew, so you know how the pieces fit even if you did not write each unit. spacedcowboy, who works on an autovectorising compiler, has the model write a huge pile of tests and runs a release gate that takes hours across five architectures. edwin0 named the gap: when the AI writes both the code and the tests, they can agree with each other and miss the same thing. These are commenters’ practices and claims, not studies.

✂️ STEAL IT

Steal the split: you design, the model implements, and something other than the model decides if it passes. Last issue’s Sphinx hook is one version of that idea.

Watch  VERDICT

Nothing to install. Use the thread as a checklist for your own review habits. It fails if "tests pass" becomes the whole policy, since edwin0’s point holds when one model wrote both sides.

The Ask HN thread

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📊 THE ATTENTION GAP
HN points at 06:30 IDT. Attention, not quality.
Timestral
563 HN
MiniMax M3.1 Flash
402 HN
Ask HN: AI code you don’t understand
298 HN
Mercury 3
226 HN
RuneScape Bench talk
167 HN
ALSO ON THE RADAR

CERN and Mistral sign a statement of intent. A strategic partnership to apply AI to science. HN had it at 304 points. A statement of intent, so no product yet. CERN →

Laminar, an RL-trained model that finds errors in agent traces. Launch HN, YC S24. We read the headline and the thread title only; unverified beyond that. HN thread →

Plex vulnerabilities exploited to drop a cryptominer. Reported as exploited in the wild. HN had it at 148 points. If you run Plex, check your version. HN thread →

📺 VIDEO OF THE DAY
RuneScape Bench talk thumbnail
RuneScape Bench: MMOs for Agents
Max Bittker at Recurse Center · about 47 min · 165,665 views on YouTube this morning · title and description read, not watched

Max Bittker’s RS-sdk turns LostCity, an open source implementation of RuneScape, into a testbed for AI experiments. The HN thread (167 points) is mostly people recalling writing RuneScape bots as kids. Confiks described a bot that broke when the game randomised colours. We read the video description and the HN thread; we did not watch the talk and have no transcript, so this is a pointer, not a review.

Watch on YouTube →

🗂️ THE BORING STUFF

Oct 19 · Copilot model policy API. REST API with GET and PATCH endpoints to read and update Copilot model policies for enterprises, teams, apps and organisations. GitHub Changelog →

Oct 19 · Copilot models deprecated today. Several models retired across most Copilot experiences: Chat, inline edits, ask and agent modes, completions. The post lists which. GitHub Changelog →

Oct 19 · Git over HTTPS may ask for authentication. During unusual traffic GitHub may temporarily require authentication for some clones and fetches of public repos over HTTPS. GitHub Changelog →

Oct 19 · CodeQL changes for macOS 27, Xcode 27 and Swift 6.4. Apple no longer ships Intel code in some system binaries CodeQL relies on to trace builds, so the Swift setup changes. GitHub Changelog →

Official pages and feed read this morning. Nothing installed or run; their numbers are theirs.
🧪 ONE THING TO TRY TONIGHT
Check the launch table against your own task.
Take one task you do every week and run it on the cheapest model from this issue and the one you use now. Read the outputs, not the chart. If you cannot tell them apart, the table was not the point.
What this issue could not see. HN (front page and comment threads), GitHub, Lobsters, dev.to, the GitHub changelog feed, and the linked primary sources were read, including the MiniMax, Mistral and Inception posts, the Harness² README and arXiv abstract, and whatmodel.sh. Reddit and X were not covered, Bluesky refused anonymous reads and LinkedIn is a login wall. The video was read through its description and the HN thread, not watched. Nothing was installed or run. Benchmark and speed numbers are vendor or author claims as labeled. Deduped against every published issue.
Talk to the editor 💬

Reply to this email with anything: what to chase, what to drop, what you want more of. Every reply shapes the next issue.

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Images: credited in each report; source screenshots and announcement artwork, not our tests.
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