Abstract
Salience 1.5 Pro is a sparse Mixture-of-Experts vision-language model: 35B total parameters,
but only ~3B active per token across 256 experts (8 routed + 1 shared). It decodes at the speed
of a small dense model while reasoning with the capacity of a 35B one — built for hard, practical
engineering work: writing and debugging real code, repo-scale edits, robust backend systems, and
driving tools and agents through long-horizon tasks, with native vision and a 262K-token context
window.
It is the flagship tier of the Salience family — engineered for people who care less about chat
pleasantries and more about whether the model can do the thing: ship the function, find the bug,
call the right tool, land the pull request.
Highlights
- Bigger and faster at once. Sparse activation means ~3B of compute for 35B of knowledge — and
a hybrid linear+full attention stack keeps long contexts fast.
- SWE-agent first. Tuned to produce runnable code, repo-scale edits, methodical debugging, and
well-formed native tool calls.
- Long-horizon agentic execution. Multi-step planning and tool orchestration that hold up across
extended task chains.
- Reasoning that shows its work. Structured, inspectable chains of thought — with a one-token
switch to turn them off when you want instant answers.
- Genuinely multimodal. Images and video are first-class inputs — read a diagram, a UI
screenshot, a stack-trace screenshot, or a whiteboard photo mid-task.
- Long context. 262,144 tokens native — whole repos and long specifications in a single prompt.
- Open weights. Apache-2.0,
transformers-native, single-file deployment.
Model overview
Table | |
|---|
| Parameters | 35B total / ~3B active (256 experts, 8 routed + 1 shared) |
| Modalities | text, image, video -> text |
| Context window | 262,144 tokens native |
| Attention | hybrid linear + full attention (full every 4th layer) |
| Precision | bfloat16 (float32 SSM components preserved) |
| Architecture | Qwen3.5 MoE (35B-A3B) + native vision encoder |
| License | Apache-2.0 |
| Library |
Multimodal MoE sibling: Salience-1.5-Flash
(30B-A3B, vision + video + 1M context).
Capabilities
Salience 1.5 Pro routes only ~3B parameters per token through a 35B expert network. Its
capability profile is built around four pillars:
- Code & SWE execution - runnable code, repo-scale edits, methodical debugging, robust backends.
- Agentic tool-use - multi-step planning, tool orchestration, long-horizon task execution.
- Deep reasoning - structured, inspectable chains of thought for hard, multi-step problems.
- Multimodal perception - diagrams, screenshots, documents, and video as first-class inputs.
Thinking
Thinking is on by default: the model reasons inside <think>...</think> before answering,
and serving stacks expose it as reasoning_content. Pass enable_thinking=False to
apply_chat_template for instant direct answers.
The model emits XML-style tool calls (<tool_call><function=...><parameter=...>), parsed
natively by vLLM / SGLang tool parsers for this model family. Provide tool schemas via the chat
template tools argument.
Intended use
Salience 1.5 Pro targets software engineering, coding agents, and technical research:
- Code generation, explanation, debugging, review, and repo-scale tasks.
- Agentic / tool-using workflows (terminal agents, browsing, ML engineering).
- Backend and systems design.
- Step-by-step reasoning and quantitative problem solving.
- Screenshot / diagram / document understanding inside engineering workflows.
It is not intended for high-stakes decisions without human review, nor as a source of truth for
medical, legal, or financial advice.
Quickstart
from transformers import AutoModelForImageTextToText, AutoProcessor
import torch
repo = "vectionlabs/Salience-1.5-Pro"
proc = AutoProcessor.from_pretrained(repo)
model = AutoModelForImageTextToText.from_pretrained(
repo, dtype="auto", device_map="auto"
)
messages = [{
"role": "user",
"content": [{"type": "text", "text": "Implement an LRU cache in Python with O(1) get/put."}],
}]
text = proc.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = proc(text=[text], return_tensors="pt").to(model.device)
out = model.generate(**inputs, max_new_tokens=2048)
print(proc.batch_decode(out[:, inputs.input_ids.shape[1]:], skip_special_tokens=True)[0])
Requires a recent transformers (>= 5.8). Vision works the same way with
{"type": "image", "image": ...} content items. Pass enable_thinking=False to
apply_chat_template for direct answers.
Quantized GGUF (recommended for local)
This is a sparse MoE (~3B active). Use Q6_K minimum (Q5_K_M acceptable) - Q4 and below
corrupt the router and cause loops / degeneration. Dense-model Q4 intuition does not apply here.
Prompting tips
- Code: specify language, constraints ("no external libraries"), and the exact I/O contract.
- Agentic / tools: pass real tool schemas via the template; the model emits XML-style calls.
- Reasoning: thinking is on by default; let it externalize its work on hard problems.
- Vision: put the image before the question in the message content.
- Sampling:
temperature=0.6-0.85, top_p=0.95, top_k=20, presence_penalty=1.1 (lower
temperature for precise code edits, higher for long agentic sessions).
Deployment
- Single / multi GPU: loads with
device_map="auto"; keep dtype="auto" so float32
components stay float32.
- Serving: vLLM / SGLang with the model family's reasoning parser (
<think> ->
reasoning_content) and XML tool-call parser.
- Quantized formats: GGUF and other community quantizations are supported (Q6_K+ for MoE).
Limitations & responsible use
- Salience 1.5 Pro can be confidently wrong. Verify factual and mathematical claims.
- Generated code may be insecure or incorrect - review before running, never execute untrusted output.
- Long-context and video inputs increase latency and memory substantially.
- Do not use it for surveillance, manipulation, or any use that violates applicable law or the
Apache-2.0 terms.
- No audio modality.
Citation
@misc{vectionlabs2026salience15pro,
title = {Salience 1.5 Pro: A Sparse-MoE Software-Engineering Agent},
author = {Vection Labs},
year = {2026},
url = {https://huggingface.co/vectionlabs/Salience-1.5-Pro}
}