Certo v1
Four 421M-parameter checkpoints for typed decisions, tool routing, web computer
use, and breadth classification. Each is a ModernBERT-large encoder with a shared
option scorer over (state, question, option) items; the checkpoints differ only
in what they were last trained on.
Checkpoints
| folder | skill | held-out result |
|---|---|---|
typed-decisions/ |
typed decisions, 2,000 decisions | 0.7715 overall; choice 0.7383, score 0.7475, noul 0.8367 |
routing/ |
tool routing, 5,575 cases | 0.8872 route; 0.9883 needs_tool |
computer-use/ |
Mind2Web Cross-Domain, 3,911 steps | 0.6863 element; 0.9665 operation; 0.8264 overall |
breadth/ |
four-epoch breadth fine-tune for the classification rows | see questions.json for the question bank |
The first three numbers are re-read from each run's score_*.json /
td_*.meta.json; the full write-up, including the external comparisons and their
caveats, is reports/MODEL_RELEASE.md in the training repository.
Files
Every folder contains the same layout:
model.safetensorsβ full checkpoint, 421.3M parameters, F16 (804 MB)rl_agent_config.jsonβ encoder, sequence budgets, fitted temperatures, abstention thresholdstokenizer/β fast tokenizerencoder/config.jsonβ ModernBERT-large configurationquestions.jsonβ the question bank the checkpoint was fitted againsttrain_report.jsonβ the run's own in-sample calibration report
Loading
# laya 0.4.2 (Apache-2.0), the package these checkpoints were trained with
from laya.train import load_checkpoint
model, tokenizer, cfg = load_checkpoint("typed-decisions")
The base encoder is answerdotai/ModernBERT-large (Apache-2.0); its configuration
is included in each folder. laya pulls its own torch, transformers and
huggingface_hub dependencies.
What these are not
- Computer use is candidate reranking. Mind2Web supplies eight candidates and the checkpoint ranks them; a deployed agent still needs a recall stage.
- Routing's edge is the decline option. On rows where a tool is gold the
checkpoint is level with a zero-shot 421M specialist; the gain is in
no_tool. - Fitted, in-distribution numbers. The external rows in the release note are zero-shot and are not like-for-like wins.
- No destructive-action or confirmation label was trained. Mind2Web has no such label; that is separate work.
License
The weight files in this repository are released under the Apache License 2.0.
Copyright 2026 the Certo authors.
The base encoder is answerdotai/ModernBERT-large (Apache-2.0); its configuration
is included in each folder. Training sources are xLAM-60k, xLAM-irrelevance,
ToolACE, Seal-Tools, Mind2Web and this project's gold corpus. Their licenses are
permissive: Apache-2.0, MIT and CC-BY-4.0.
If you redistribute these weights, keep the license and copyright notice with them.