Model anatomy
Qwen3.8-Flash-Next
A multimodal ultra-sparse MoE preview of the Qwen4 architecture: a 125B main model, 51B bigram/trigram PLE capacity and a separately published 4B MTP auxiliary parameter pool, with 6B parameters active per token, 48 language blocks repeating 3 × Gated DeltaNet + 1 × Qwen Sparse Attention, and four-branch Gated Residual.
Token path
From token id to next-token logits
Follow the structural path first, then inspect one decoder block at full resolution.
Per-Layer Embedding is a side-memory injection, not part of the ordinary token-embedding matrix: hashed 2-gram + 3-gram features from a 51B published parameter pool enter decoder layer 2. The released implementation supports host-memory offload for this deterministic lookup table.
Decoder microscope
Layer 1
Select any layer to see the checkpoint-backed attention, feed-forward and residual anatomy.
- Key heads
- 16
- Value heads
- 48
- Key / value dim
- 128 / 128
- Short conv
- kernel 4
Recurrent state: token history is compressed into a fixed-size state update rather than a full KV history for this layer.
- Routed experts
- 512
- Active routed
- 10 / token
- Shared experts
- 1
- Expert width
- 640
- Routing
- learned
router logits → softmax → top-10 routed experts → selected-weight normalization; one shared expert is computed alongside the routed path and modulated by its own sigmoid gate
- Topology
- GR
- Expansion
- 4 streams
- Mixer rank
- 320
- Gate
- input-dependent
Four residual branches are read and written through fine-grained dynamic gates around each sublayer.
Parameter & memory surface
What is stored, and what participates per token?
Source-backed parameter pools and active-path quantities; stored inventory is not assumed to be read in full for every token.
125B main model + 51B N-gram embedding + 4.0B MTP (outside ordinary inference graph). Stored inventory is a deployment/storage boundary; pools outside ordinary inference are not counted as per-token execution.
Published active-per-token count for the main model. Side-memory lookups and auxiliary pools are accounted separately.
Recurrent state: token history is compressed into a fixed-size state update rather than a full KV history for this layer.
Active routed + shared experts for the selected layer.
Evidence for layer 1
Trace every structural claim back to source
3 sources currently support this layer view.
Official release description: early Qwen4 architecture preview, 125B main model + 51B N-gram embeddings, 6B active parameters, GDN + QSA, four-branch Gated Residual, N-gram Embedding, 262,144 native context and optional YaRN extension to 1M.
config · rev 34567a4Qwen3.8-Flash-Next released config.jsonConcrete 48-layer 3:1 linear/full schedule, 2,560d hidden width, QSA 4×128d indexer with 4× compression and 2,048-token budget, 16-key/48-value-head GDN, 512 routed experts with top-10 activation, GR hc_count=4/hc_lowrank=320, PLE layer 2, and the 27-block vision encoder.
implementation · rev fc5c5bdTransformers Qwen4-Exp implementation contractPublic Qwen4-Exp model definition and forward contract, including QSA compressed-block selection, one-key-head indexer, incomplete trailing-block handling, Gated Residual elementwise input mixing plus branch-wise injection, PLE one-based layer IDs, sigmoid-gated shared-expert execution and cached-generation state behavior.