my new favorite of way of using fable:
step 1. ask it to write a plan
step 2: "please get second opinions from codex CLI using gpt-5.6-sol @ max effort and kimi CLI using kimi 3. Revise your plan with any sound findings. repeat until convergence or up to 5 rounds."
I have a report full of security issues of a software I'm working on.
Codex won't fix them because of Cyber guardrails
Fable won't fix them because of Cyber guardrails
Kimi K3 fixed them all. No restrictions, just gets the job done.
This will end badly for OpenAI & Anthropic.
We tested Kimi K3 and Fable on a real bug from the Cline repo, and found that while both models were able to fix it - Fable wins on speed & Kimi wins on cost.
- Kimi used 1.7x more tokens than Fable (1.2M vs. 730K)
- Fable finished 3.4x faster - 3.5 min and 18 tool calls vs. Kimi’s 12 min and 34 tool calls.
- Kimi cost 2.3x less ($0.92 vs. $2.13) thanks to its 3.3x per-token discount
Both runs used the same Cline harness, and the traces indicate that Kimi is RL trained to spend more tokens thinking and verifying before completing.
This is the first time we've seen an open weight model compete head to head with SOTA. Congratulations to the @Kimi_Moonshot team on this milestone!
Started with the $39 plan and used it up, @Kimi_Moonshot is a user-aligned company I'm happy to send money to. GLM-5.2 feels Opus tier, Kimi K3 feels Fable tier!
🧵 DeepSeek appear to have engaged, or be engaging in, a large-scale operation to collect outputs from proprietary models (including Claude Fable 5) for certain requests via their API as part of a distillation effort.
After seeing such claims circulating earlier today, we conducted an investigation into them on our Discord. We found that, when "Deepseek V4" was used within OpenCode - via their official API - for complex prompts (i.e. 3D games) and combined with a knowledge-related query, the model provides virtually identical outputs to Fable 5. CoT structure is also very different from what is typically expected from Deepseek models. Both of these behaviours revert to what is expected for V4 when simpler prompts were used.
When "Deepseek V4" was asked to incorporate answers to questions related to cyber or bio tasks that we verified hit Fable's classifiers into its 3D games, outputs tanked in quality. This is very difficult to explain unless the request was routed to Fable and fell back after hitting a classifier.
For complex code prompts without anything else mixed in, like 3D games, outputs were remarkably similar to those produced by Fable 5.
We were able to produce these results most consistently via OpenCode and the official Deepseek API combined with a prompt that specifies a complex code task. Deepseek have continued to modify their routing system since, as we have observed changes in behaviour and CoT style compared to those seen previously. Our investigation was conducted from 7AM-8AM PT.
Another pattern is agent-to-agent communication, allowing Claude to coordinate and delegate tasks.
Claude Managed Agents supports this with multi-agent: agents can use different models, prompts, and tools while sharing sandboxes or vault credentials.
I think I finally figured out how to use AI at scale
of course, the fact Fable is good is part of it. but I also changed how I work, and it all comes down to one key realization: you don't need to audit the code, but you NEED to audit the *choices* it made. if you just do that, things will work out, and you'll never lose a codebase to chaos. with Fable at least, the following seems to hold:
if I give it a good decision:
Fable implements it PERFECTLY
if I let it decide instead:
Fable may make some bad choices
that's how I see Fable: as a perfect execution machine capable of converting good decisions into good codebases, no matter how large. given a concrete plan, it lands its implementation. but when anything is underspecified, it can, and will, make bad choices. that's what you must audit.
"while working on this, which choices did you make that you're not confident of? list all."
then, you just review that. not the git diff, not 1000's of lines of code. just the choices it made along the way.
below is a fresh example. overnight, I asked Fable to fix an issue related to MatMul parallelizing worse than expected. it tracked the culprit with perfection, and landed a solution that DID work. but the solution was not general. it just doubled a buffer, which coincidently fixed the program at hands, but the underlying issue was still present.
when it completed the job, it declared success. if I just merged it blindly, the issue would still be dormant. that's the main mistake one can do with AI. instead, I asked it to spell out all decisions it made, spotted the bad one, corrected its course, and now the codebase is clean, correct and the issue is gone for good
I really think that if you do that religiously - i.e., NEVER merge without this "which decisions you made?" audit - you can go VERY far without ever reading a single line of code. at least on Bend, this is working incredibly well. despite heavy use of AI to implement an ungodly amount of features I could never dream of, the codebase is still in a superb state, with no signs of degradation
fresh example below ↓
As much as I'm happy that Fable 5 is staying, I'm equally concerned that Opus 5 will be an underwhelming release, similar to Sonnet 5.
What gives me hope, however, is that Mythos preview rumors surfaced back in March, and Fable 5 is known to be Mythos with heavy guardrails. Therefore, I expect the next version, Fable 5.6 or at least 6, to arrive soon.
OH: “i’ve switched to Kimi from claude for a bunch of work. it’s just so much more fun because it just does the thing instead of lecturing you”
Woke lobotomized models are the enemy of American competitiveness.
Claude Code 2.1.214 has been released.
47 CLI changes
Highlights:
• Added EndConversation tool to end sessions with abusive users or jailbreak attempts and halt interaction
• Added permission prompts for Docker/Podman daemon-redirect flags to prevent accidental remote daemon access
• Edit tool makes literal string replacements in files so edits affect only exact specified text, not patterns
Complete details available in thread ↓