Implement Qwen text core

metal/qwen38.metal

@@ -0,0 +1,408 @@
+// Qwen3.8 Flash Next primitives. Rust owns the graph and all state lifetimes;
+// this file contains only the data-parallel kernels executed by Metal.
+
+struct qwen_kernel_args {
+    uint u[16];
+    float f[8];
+};
+
+static inline float qwen_bf16(ushort value) {
+    return as_type<float>((uint)value << 16);
+}
+
+static inline ushort qwen_to_bf16(float value) {
+    uint bits = as_type<uint>(value);
+    bits += 0x7fffu + ((bits >> 16) & 1u);
+    return (ushort)(bits >> 16);
+}
+
+static inline float qwen_quant_value(
+        device const uint *packed,
+        device const ushort *scales,
+        device const ushort *biases,
+        uint row,
+        uint column,
+        uint in_dim,
+        uint bits,
+        uint group_size) {
+    const uint per_word = 32u / bits;
+    const uint packed_columns = in_dim / per_word;
+    const uint groups = in_dim / group_size;
+    const uint word = packed[(ulong)row * packed_columns + column / per_word];
+    const uint mask = (1u << bits) - 1u;
+    const uint quant = (word >> ((column % per_word) * bits)) & mask;
+    const uint group = row * groups + column / group_size;
+    return fma((float)quant, qwen_bf16(scales[group]), qwen_bf16(biases[group]));
+}
+
+kernel void kernel_qwen_affine_mv(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device const uint *packed [[buffer(5)]],
+        device const ushort *scales [[buffer(6)]],
+        device const ushort *biases [[buffer(7)]],
+        uint row [[thread_position_in_grid]]) {
+    const uint in_dim = args.u[0];
+    const uint out_dim = args.u[1];
+    if (row >= out_dim) return;
+    float sum = 0.0f;
+    for (uint column = 0; column < in_dim; column++) {
+        sum = fma(qwen_quant_value(packed, scales, biases, row, column,
+                                  in_dim, args.u[2], args.u[3]), x[column], sum);
+    }
+    out[row] = sum;
+}
+
+kernel void kernel_qwen_affine_embedding(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const uint *packed [[buffer(5)]],
+        device const ushort *scales [[buffer(6)]],
+        device const ushort *biases [[buffer(7)]],
+        uint column [[thread_position_in_grid]]) {
+    if (column >= args.u[0]) return;
+    out[column] = qwen_quant_value(packed, scales, biases, args.u[4], column,
+                                   args.u[0], args.u[2], args.u[3]);
+}
+
+kernel void kernel_qwen_bf16_mv(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device const ushort *weights [[buffer(5)]],
+        uint row [[thread_position_in_grid]]) {
+    if (row >= args.u[1]) return;
+    float sum = 0.0f;
+    for (uint column = 0; column < args.u[0]; column++) {
+        sum = fma(qwen_bf16(weights[(ulong)row * args.u[0] + column]), x[column], sum);
+    }
+    out[row] = sum;
+}
+
+kernel void kernel_qwen_repeat4(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index < args.u[0] * 4u) out[index] = x[index % args.u[0]];
+}
+
+kernel void kernel_qwen_zero_rms(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device const ushort *weight [[buffer(5)]],
+        uint group [[thread_position_in_grid]]) {
+    const uint width = args.u[0];
+    const uint group_size = args.u[1];
+    if (group >= width / group_size) return;
+    const uint start = group * group_size;
+    float variance = 0.0f;
+    for (uint i = 0; i < group_size; i++) variance = fma(x[start + i], x[start + i], variance);
+    const float scale = rsqrt(variance / (float)group_size + args.f[0]);
+    for (uint i = 0; i < group_size; i++) {
+        const uint index = start + i;
+        out[index] = x[index] * scale * (1.0f + qwen_bf16(weight[index]));
+    }
+}
+
+kernel void kernel_qwen_silu_div4(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index >= args.u[0]) return;
+    const float value = x[index] * 0.25f;
+    out[index] = value / (1.0f + exp(-value));
+}
+
+kernel void kernel_qwen_sigmoid(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index < args.u[0]) out[index] = 1.0f / (1.0f + exp(-x[index]));
+}
+
+kernel void kernel_qwen_sigmoid2_div4(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index < args.u[0]) out[index] = 2.0f / (1.0f + exp(-x[index] * 0.25f));
+}
+
+kernel void kernel_qwen_hyper_mix(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *normalized [[buffer(2)]],
+        device const float *mix [[buffer(3)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index >= args.u[0]) return;
+    float value = 0.0f;
+    for (uint stream = 0; stream < 4u; stream++) {
+        const uint offset = stream * args.u[0] + index;
+        value = fma(normalized[offset], mix[offset], value);
+    }
+    out[index] = value * 0.25f;
+}
+
+kernel void kernel_qwen_hyper_inject(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *residual [[buffer(2)]],
+        device const float *block [[buffer(3)]],
+        device const float *gate [[buffer(4)]],
+        uint index [[thread_position_in_grid]]) {
+    const uint hidden = args.u[0];
+    if (index >= hidden * 4u) return;
+    out[index] = residual[index] + block[index % hidden] * gate[index / hidden];
+}
+
+kernel void kernel_qwen_conv_silu(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device ushort *state [[buffer(3)]],
+        device const ushort *weight [[buffer(5)]],
+        uint channel [[thread_position_in_grid]]) {
+    if (channel >= args.u[0]) return;
+    device ushort *history = state + (ulong)channel * 3u;
+    float value = fma(qwen_bf16(history[0]), qwen_bf16(weight[(ulong)channel * 4u]),
+                  fma(qwen_bf16(history[1]), qwen_bf16(weight[(ulong)channel * 4u + 1u]),
+                  fma(qwen_bf16(history[2]), qwen_bf16(weight[(ulong)channel * 4u + 2u]),
+                      x[channel] * qwen_bf16(weight[(ulong)channel * 4u + 3u]))));
+    history[0] = history[1];
+    history[1] = history[2];
+    history[2] = qwen_to_bf16(x[channel]);
+    out[channel] = value / (1.0f + exp(-value));
+}
+
+kernel void kernel_qwen_gdn_step(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *qkv [[buffer(2)]],
+        device const float *controls [[buffer(3)]],
+        device float *state [[buffer(4)]],
+        device const ushort *a_log [[buffer(5)]],
+        device const ushort *dt_bias [[buffer(6)]],
+        uint2 gid [[thread_position_in_grid]]) {
+    const uint value_index = gid.x;
+    const uint head = gid.y;
+    const uint dim = args.u[0];
+    const uint key_heads = args.u[1];
+    const uint value_heads = args.u[2];
+    if (value_index >= dim || head >= value_heads) return;
+    const uint key_head = head / (value_heads / key_heads);
+    device const float *q_raw = qkv + (ulong)key_head * dim;
+    device const float *k_raw = qkv + (ulong)key_heads * dim + (ulong)key_head * dim;
+    device const float *value = qkv + (ulong)key_heads * dim * 2u + (ulong)head * dim;
+    float qsum = 0.0f;
+    float ksum = 0.0f;
+    for (uint i = 0; i < dim; i++) {
+        qsum = fma(q_raw[i], q_raw[i], qsum);
+        ksum = fma(k_raw[i], k_raw[i], ksum);
+    }
+    const float qscale = rsqrt(qsum + args.f[0]) * rsqrt((float)dim);
+    const float kscale = rsqrt(ksum + args.f[0]);
+    const float beta = 1.0f / (1.0f + exp(-controls[args.u[3] + head]));
+    const float step = controls[args.u[4] + head] + qwen_bf16(dt_bias[head]);
+    const float softplus = max(step, 0.0f) + log(1.0f + exp(-abs(step)));
+    const float decay = exp(-exp(qwen_bf16(a_log[head])) * softplus);
+    device float *column = state + ((ulong)head * dim * dim) + value_index;
+    float prediction = 0.0f;
+    for (uint i = 0; i < dim; i++) {
+        prediction = fma(column[(ulong)i * dim] * decay, k_raw[i] * kscale, prediction);
+    }
+    const float delta = (value[value_index] - prediction) * beta;
+    float result = 0.0f;
+    for (uint i = 0; i < dim; i++) {
+        const ulong offset = (ulong)i * dim;
+        const float updated = column[offset] * decay + k_raw[i] * kscale * delta;
+        column[offset] = updated;
+        result = fma(updated, q_raw[i] * qscale, result);
+    }
+    device float *head_out = out + (ulong)head * dim;
+    head_out[value_index] = result;
+}
+
+kernel void kernel_qwen_gdn_norm_gate(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device const float *controls [[buffer(3)]],
+        device const ushort *weight [[buffer(5)]],
+        uint head [[thread_position_in_grid]]) {
+    const uint dim = args.u[0];
+    if (head >= args.u[1]) return;
+    device const float *row = x + (ulong)head * dim;
+    float variance = 0.0f;
+    for (uint i = 0; i < dim; i++) variance = fma(row[i], row[i], variance);
+    const float scale = rsqrt(variance / (float)dim + args.f[0]);
+    for (uint i = 0; i < dim; i++) {
+        const ulong index = (ulong)head * dim + i;
+        out[index] = row[i] * scale * qwen_bf16(weight[i]) /
+                     (1.0f + exp(-controls[index]));
+    }
+}
+
+kernel void kernel_qwen_swiglu(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *gate [[buffer(2)]],
+        device const float *up [[buffer(3)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index >= args.u[0]) return;
+    out[index] = gate[index] / (1.0f + exp(-gate[index])) * up[index];
+}
+
+kernel void kernel_qwen_route_top10(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device int *ids [[buffer(1)]],
+        device float *weights [[buffer(2)]],
+        device const float *logits [[buffer(3)]],
+        uint gid [[thread_position_in_grid]]) {
+    if (gid != 0u) return;
+    float max_value = -INFINITY;
+    for (uint i = 0; i < args.u[0]; i++) max_value = max(max_value, logits[i]);
+    float sum = 0.0f;
+    for (uint i = 0; i < args.u[0]; i++) sum += exp(logits[i] - max_value);
+    float selected_sum = 0.0f;
+    for (uint slot = 0; slot < 10u; slot++) {
+        float best = -1.0f;
+        int best_id = -1;
+        for (uint i = 0; i < args.u[0]; i++) {
+            bool used = false;
+            for (uint j = 0; j < slot; j++) used = used || ids[j] == (int)i;
+            const float probability = exp(logits[i] - max_value) / sum;
+            if (!used && probability > best) {
+                best = probability;
+                best_id = (int)i;
+            }
+        }
+        ids[slot] = best_id;
+        weights[slot] = best;
+        selected_sum += best;
+    }
+    for (uint slot = 0; slot < 10u; slot++) weights[slot] /= selected_sum;
+}
+
+kernel void kernel_qwen_accumulate(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index < args.u[0]) out[index] += x[index] * args.f[0];
+}
+
+kernel void kernel_qwen_accumulate_sigmoid_scalar(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device const float *gate [[buffer(3)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index < args.u[0]) out[index] += x[index] / (1.0f + exp(-gate[0]));
+}
+
+kernel void kernel_qwen_split_q_gate(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *q [[buffer(1)]],
+        device const float *packed [[buffer(2)]],
+        device float *gate [[buffer(3)]],
+        uint index [[thread_position_in_grid]]) {
+    const uint heads = args.u[0];
+    const uint dim = args.u[1];
+    if (index >= heads * dim) return;
+    const uint head = index / dim;
+    const uint column = index % dim;
+    q[index] = packed[(ulong)head * dim * 2u + column];
+    gate[index] = packed[(ulong)head * dim * 2u + dim + column];
+}
+
+kernel void kernel_qwen_head_norm_rope(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *x [[buffer(2)]],
+        device const ushort *weight [[buffer(5)]],
+        uint2 gid [[thread_position_in_grid]]) {
+    const uint column = gid.x;
+    const uint head = gid.y;
+    const uint dim = args.u[0];
+    const uint rotary = args.u[1];
+    if (column >= dim || head >= args.u[2]) return;
+    device const float *row = x + (ulong)head * dim;
+    float variance = 0.0f;
+    for (uint i = 0; i < dim; i++) variance = fma(row[i], row[i], variance);
+    const float scale = rsqrt(variance / (float)dim + args.f[0]);
+    float value = row[column] * scale * (1.0f + qwen_bf16(weight[column]));
+    if (column < rotary) {
+        const uint rotary_half = rotary / 2u;
+        const uint pair = column < rotary_half ? column + rotary_half : column - rotary_half;
+        const float paired = row[pair] * scale * (1.0f + qwen_bf16(weight[pair]));
+        const float theta = (float)args.u[3] * pow(args.f[1], -2.0f * (float)(column % rotary_half) / (float)rotary);
+        value = value * cos(theta) + (column < rotary_half ? -paired : paired) * sin(theta);
+    }
+    out[(ulong)head * dim + column] = value;
+}
+
+kernel void kernel_qwen_store_kv_bf16(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device ushort *cache [[buffer(1)]],
+        device const float *key [[buffer(2)]],
+        device const float *value [[buffer(3)]],
+        uint index [[thread_position_in_grid]]) {
+    const uint width = args.u[0];
+    if (index >= width) return;
+    const ulong base = (ulong)args.u[1] * width * 2u;
+    cache[base + index] = qwen_to_bf16(key[index]);
+    cache[base + width + index] = qwen_to_bf16(value[index]);
+}
+
+kernel void kernel_qwen_dense_attention(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *query [[buffer(2)]],
+        device const ushort *cache [[buffer(3)]],
+        uint head [[thread_position_in_grid]]) {
+    const uint heads = args.u[0];
+    const uint kv_heads = args.u[1];
+    const uint dim = args.u[2];
+    const uint tokens = args.u[3];
+    if (head >= heads) return;
+    const uint kv_head = head / (heads / kv_heads);
+    float max_score = -INFINITY;
+    for (uint token = 0; token < tokens; token++) {
+        const ulong base = (ulong)token * kv_heads * dim * 2u + (ulong)kv_head * dim;
+        float score = 0.0f;
+        for (uint i = 0; i < dim; i++) score = fma(query[(ulong)head * dim + i], qwen_bf16(cache[base + i]), score);
+        max_score = max(max_score, score * rsqrt((float)dim));
+    }
+    float denominator = 0.0f;
+    for (uint token = 0; token < tokens; token++) {
+        const ulong base = (ulong)token * kv_heads * dim * 2u + (ulong)kv_head * dim;
+        float score = 0.0f;
+        for (uint i = 0; i < dim; i++) score = fma(query[(ulong)head * dim + i], qwen_bf16(cache[base + i]), score);
+        denominator += exp(score * rsqrt((float)dim) - max_score);
+    }
+    for (uint column = 0; column < dim; column++) {
+        float value = 0.0f;
+        for (uint token = 0; token < tokens; token++) {
+            const ulong base = (ulong)token * kv_heads * dim * 2u + (ulong)kv_head * dim;
+            float score = 0.0f;
+            for (uint i = 0; i < dim; i++) score = fma(query[(ulong)head * dim + i], qwen_bf16(cache[base + i]), score);
+            const float probability = exp(score * rsqrt((float)dim) - max_score) / denominator;
+            value = fma(probability, qwen_bf16(cache[base + kv_heads * dim + column]), value);
+        }
+        out[(ulong)head * dim + column] = value;
+    }
+}
+
+kernel void kernel_qwen_gate_attention(
+        constant qwen_kernel_args &args [[buffer(0)]],
+        device float *out [[buffer(1)]],
+        device const float *attention [[buffer(2)]],
+        device const float *gate [[buffer(3)]],
+        uint index [[thread_position_in_grid]]) {
+    if (index < args.u[0]) out[index] = attention[index] / (1.0f + exp(-gate[index]));
+}

native/metal/ds4_gpu.h

@@ -128,6 +128,30 @@ int ds4_gpu_set_aux_model_map_range(const void *model_map,
                                     uint64_t map_offset,
                                     uint64_t map_size);
 int ds4_gpu_set_model_map_spans(const void *model_map, uint64_t model_size, const uint64_t *offsets, const uint64_t *sizes, uint32_t count, uint64_t max_tensor_bytes);
+
+typedef struct {
+    const void *map;
+    uint64_t size;
+    uint64_t offset;
+    uint64_t bytes;
+} ds4_gpu_qwen_weight_view;
+
+typedef struct {
+    uint32_t u[16];
+    float f[8];
+} ds4_gpu_qwen_kernel_args;
+
+int ds4_gpu_qwen_dispatch(
+        const char *kernel,
+        ds4_gpu_tensor *out,
+        const ds4_gpu_tensor *a,
+        const ds4_gpu_tensor *b,
+        const ds4_gpu_tensor *c,
+        const ds4_gpu_qwen_weight_view *weights,
+        uint32_t weight_count,
+        const ds4_gpu_qwen_kernel_args *args,
+        uint32_t grid_x,
+        uint32_t grid_y);
 int ds4_gpu_cache_model_range(const void *model_map, uint64_t model_size, uint64_t offset, uint64_t bytes, const char *label);
 int ds4_gpu_cache_q8_f16_range(const void *model_map, uint64_t model_size, uint64_t offset, uint64_t bytes, uint64_t in_dim, uint64_t out_dim, const char *label);
 int ds4_gpu_q8_cache_suppressed(void);

native/metal/ds4_metal.m

@@ -4359,6 +4359,7 @@ static NSString *ds4_gpu_full_source(void) {
         @[@"DS4_METAL_GLM53_BF16_SOURCE", @"metal/glm53_bf16.metal"],
         @[@"DS4_METAL_GLM53_VISION_SOURCE", @"metal/glm53_vision.metal"],
         @[@"DS4_METAL_GLM53_KDA_SOURCE",  @"metal/glm53_kda.metal"],
+        @[@"DS4_METAL_QWEN38_SOURCE",     @"metal/qwen38.metal"],
         @[@"DS4_METAL_MOE_SOURCE",        @"metal/moe.metal"],
         @[@"DS4_METAL_DSV4_HC_SOURCE",    @"metal/dsv4_hc.metal"],
         @[@"DS4_METAL_UNARY_SOURCE",      @"metal/unary.metal"],
@@ -11737,6 +11738,68 @@ static id<MTLBuffer> ds4_gpu_wrap_model_exact_range_owned(
                                                DS4_GPU_EXACT_VIEW_OWNED);
 }
 
+int ds4_gpu_qwen_dispatch(
+        const char *kernel,
+        ds4_gpu_tensor *out,
+        const ds4_gpu_tensor *a,
+        const ds4_gpu_tensor *b,
+        const ds4_gpu_tensor *c,
+        const ds4_gpu_qwen_weight_view *weights,
+        uint32_t weight_count,
+        const ds4_gpu_qwen_kernel_args *args,
+        uint32_t grid_x,
+        uint32_t grid_y) {
+    if (!kernel || !out || !args || grid_x == 0 || grid_y == 0 ||
+        weight_count > 3 || (weight_count != 0 && !weights)) {
+        return 0;
+    }
+    id<MTLComputePipelineState> pipeline = ds4_gpu_get_pipeline(kernel);
+    if (!pipeline) return 0;
+
+    int owned = 0;
+    id<MTLCommandBuffer> cb = ds4_gpu_command_buffer(&owned);
+    if (!cb) return 0;
+    id<MTLComputeCommandEncoder> enc = ds4_gpu_compute_encoder(cb);
+    if (!enc) return 0;
+    [enc setComputePipelineState:pipeline];
+    [enc setBytes:args length:sizeof(*args) atIndex:0];
+
+    const DS4MetalTensor *tensors[4] = {
+        ds4_gpu_tensor_const_obj(out),
+        a ? ds4_gpu_tensor_const_obj(a) : nil,
+        b ? ds4_gpu_tensor_const_obj(b) : nil,
+        c ? ds4_gpu_tensor_const_obj(c) : nil,
+    };
+    for (uint32_t i = 0; i < 4; i++) {
+        if (tensors[i]) {
+            [enc setBuffer:tensors[i].buffer offset:(NSUInteger)tensors[i].offset atIndex:1 + i];
+        }
+    }
+    for (uint32_t i = 0; i < weight_count; i++) {
+        uint64_t inner = 0;
+        id<MTLBuffer> weight = ds4_gpu_wrap_model_exact_range(
+            weights[i].map,
+            weights[i].size,
+            weights[i].offset,
+            weights[i].bytes,
+            &inner);
+        if (!weight) {
+            ds4_gpu_end_compute_encoder(cb, enc);
+            if (owned) [cb commit];
+            return 0;
+        }
+        [enc setBuffer:weight offset:(NSUInteger)inner atIndex:5 + i];
+    }
+
+    const NSUInteger width = pipeline.threadExecutionWidth;
+    const NSUInteger max_threads = pipeline.maxTotalThreadsPerThreadgroup;
+    const NSUInteger threads = MIN(MAX(width, 1u), max_threads);
+    [enc dispatchThreads:MTLSizeMake(grid_x, grid_y, 1)
+      threadsPerThreadgroup:MTLSizeMake(threads, 1, 1)];
+    ds4_gpu_end_compute_encoder(cb, enc);
+    return owned ? ds4_gpu_finish_command_buffer(cb, 1, kernel) : 1;
+}
+
 uint32_t ds4_gpu_stream_expert_cache_configured_count(void) {
     uint32_t budget = ds4_gpu_stream_expert_cache_configured_budget();
     if (budget > DS4_METAL_STREAM_EXPERT_CACHE_MAX_ENTRIES) {

src/engine.rs

@@ -53,6 +53,7 @@ pub(crate) fn checkpoint_model(path: &Path) -> Option<ModelChoice> {
     let model_size_offset = match &magic {
         b"DS4RKV01" => 40,
         b"DS4GLM01" => 44,
+        b"DS4QWN01" => return Some(ModelChoice::Qwen38FlashNext),
         _ => return None,
     };
     file.seek(SeekFrom::Start(model_size_offset)).ok()?;
@@ -301,6 +302,115 @@ pub(crate) struct Model {
     tokenizer: Tokenizer,
 }
 
+enum LoadedModel {
+    Gguf(Box<Model>),
+    Qwen(Box<qwen::QwenModel>),
+}
+
+impl From<Model> for LoadedModel {
+    fn from(model: Model) -> Self {
+        Self::Gguf(Box::new(model))
+    }
+}
+
+#[derive(Clone, Copy)]
+enum ModelRef<'a> {
+    Gguf(&'a Model),
+    Qwen(&'a qwen::QwenModel),
+}
+
+impl LoadedModel {
+    fn open(settings: &EngineSettings) -> Result<Self, String> {
+        if settings.model.is_qwen38() {
+            validate_engine_artifacts(
+                settings.model,
+                settings.speculative.dspark,
+                &settings.artifacts,
+            )?;
+            let context = u32::try_from(settings.context_tokens)
+                .map_err(|_| "Qwen context must be a positive whole number")?;
+            qwen::QwenModel::open(&settings.artifacts.model, context)
+                .map(Box::new)
+                .map(Self::Qwen)
+        } else {
+            Model::open(settings).map(Box::new).map(Self::Gguf)
+        }
+    }
+}
+
+impl ModelRef<'_> {
+    fn summary(self) -> ModelSummary {
+        match self {
+            Self::Gguf(model) => model.summary(),
+            Self::Qwen(model) => model.summary(),
+        }
+    }
+
+    fn render_conversation(
+        self,
+        system: &str,
+        messages: &[ChatTurn],
+        reasoning: ReasoningMode,
+    ) -> Vec<i32> {
+        match self {
+            Self::Gguf(model) => model.render_conversation(system, messages, reasoning),
+            Self::Qwen(model) => model.render_conversation(system, messages, reasoning),
+        }
+    }
+
+    fn render_history(
+        self,
+        system: &str,
+        messages: &[ChatTurn],
+        reasoning: ReasoningMode,
+    ) -> Vec<i32> {
+        match self {
+            Self::Gguf(model) => model.render_history(system, messages, reasoning),
+            Self::Qwen(model) => model.render_history(system, messages, reasoning),
+        }
+    }
+
+    fn render_continuation(
+        self,
+        prompt: &str,
+        reasoning: ReasoningMode,
+        skip_previous_eos: bool,
+    ) -> Vec<i32> {
+        match self {
+            Self::Gguf(model) => model.render_continuation(prompt, reasoning, skip_previous_eos),
+            Self::Qwen(model) => model.render_continuation(prompt, reasoning, skip_previous_eos),
+        }
+    }
+
+    fn token_bytes(self, token: i32) -> Option<Vec<u8>> {
+        match self {
+            Self::Gguf(model) => model.token_bytes(token),
+            Self::Qwen(model) => model.token_bytes(token),
+        }
+    }
+
+    fn is_stop_token_for_reasoning(self, token: i32, reasoning: ReasoningMode) -> bool {
+        match self {
+            Self::Gguf(model) => model.is_stop_token_for_reasoning(token, reasoning),
+            Self::Qwen(model) => model.is_stop_token_for_reasoning(token, reasoning),
+        }
+    }
+
+    fn is_think_start_token(self, token: i32) -> bool {
+        match self {
+            Self::Gguf(model) => model.is_think_start_token(token),
+            Self::Qwen(model) => model.is_think_start_token(token),
+        }
+    }
+
+    fn is_think_end_token(self, token: i32) -> bool {
+        match self {
+            Self::Gguf(model) => model.is_think_end_token(token),
+            Self::Qwen(model) => model.is_think_end_token(token),
+        }
+    }
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub(crate) struct ModelSummary {
     pub(crate) model: ModelChoice,
@@ -320,18 +430,7 @@ impl Model {
             &settings.artifacts,
         )?;
         if settings.model.is_qwen38() {
-            let context = u32::try_from(settings.context_tokens)
+            return Err("Qwen must be opened through its dedicated safetensors loader".into());
-                .map_err(|_| "Qwen context must be a positive whole number")?;
-            let loaded = qwen::load(&settings.artifacts.model, context, false)?;
-            return Err(format!(
-                "Qwen3.8 artifacts are valid, but its Rust Metal execution backend is not available until issue #95. Memory plan: {} resident core bytes, {} mapped PLE bytes, {} optional MTP bytes, {} KV/recurrent bytes, {} prefill transient bytes, {} admitted bytes.",
-                loaded.memory.resident_core,
-                loaded.memory.mapped_ple,
-                loaded.memory.optional_mtp,
-                loaded.memory.kv_and_recurrent,
-                loaded.memory.prefill_transient,
-                loaded.memory.admission,
-            ));
         }
         let mut model = Self::open_main(&settings.artifacts.model, settings.model)?;
         if settings.execution.warm_weights {
@@ -622,7 +721,7 @@ impl Generator {
     pub(crate) fn open(settings: &EngineSettings, metrics: Arc<Metrics>) -> Result<Self, String> {
         let simulated_memory =
             SimulatedMemory::acquire(settings.diagnostics.simulated_used_memory_bytes)?;
-        let model = Model::open(settings)?;
+        let model = LoadedModel::open(settings)?;
         let executor = metal::Executor::open_configured(
             model,
             settings.context_tokens.max(1) as u32,

src/engine/metal.rs

@@ -3,16 +3,18 @@ mod glm;
 mod gpu;
 mod hotlist;
 mod profile;
+mod qwen;
 mod vision;
 pub(super) use vision::VisionEmbedding;
 
 use glm::GlmExecutor;
 use gpu::*;
 use profile::ExpertProfile;
+use qwen::QwenExecutor;
 
 use super::gguf::{BF16, F16, F32, Gguf, IQ2_XXS, MXFP4, Q2_K, Q4_K, Q8_0, Tensor as GgufTensor};
 use super::validation::{DsparkConfig, SupportKind, dspark_config};
-use super::{Model, ModelFamily, Rng, exact_delta_sample};
+use super::{LoadedModel, Model, ModelFamily, ModelRef, Rng, exact_delta_sample};
 use crate::model::ModelChoice;
 use crate::settings::{
     EngineSpeculativeSettings, EngineSsdSettings, EngineSteeringSettings, ReasoningMode,
@@ -44,7 +46,7 @@ fn environment_present(name: &CStr) -> bool {
     !unsafe { getenv(name.as_ptr()) }.is_null()
 }
 
-const SOURCES: [(&str, &str); 22] = [
+const SOURCES: [(&str, &str); 23] = [
     ("DS4_METAL_FLASH_ATTN_SOURCE", "flash_attn.metal"),
     ("DS4_METAL_DENSE_SOURCE", "dense.metal"),
     ("DS4_METAL_MOE_SOURCE", "moe.metal"),
@@ -67,6 +69,7 @@ const SOURCES: [(&str, &str); 22] = [
     ("DS4_METAL_GLM53_BF16_SOURCE", "glm53_bf16.metal"),
     ("DS4_METAL_GLM53_VISION_SOURCE", "glm53_vision.metal"),
     ("DS4_METAL_GLM53_KDA_SOURCE", "glm53_kda.metal"),
+    ("DS4_METAL_QWEN38_SOURCE", "qwen38.metal"),
 ];
 
 // The Metal boundary uses this only to decide whether diagnostic logs get ANSI
@@ -4360,15 +4363,17 @@ impl DeepSeekExecutor {
     }
 }
 
-/// Model-family dispatch over the two Rust-owned Metal graphs.
+/// Model-family dispatch over the Rust-owned Metal graphs.
 pub(super) enum Executor {
     DeepSeek(Box<DeepSeekExecutor>),
     Glm(Box<GlmExecutor>),
+    Qwen(Box<QwenExecutor>),
 }
 
 pub(super) enum ResidentState {
     DeepSeek(Box<DeepSeekResidentState>),
     Glm(Box<glm::GlmResidentState>),
+    Qwen(Box<qwen::QwenResidentState>),
 }
 
 impl Executor {
@@ -4380,7 +4385,7 @@ impl Executor {
         prefill_chunk: u32,
     ) -> Result<Self, String> {
         Self::open_configured(
-            model,
+            LoadedModel::from(model),
             context,
             quality,
             prefill_chunk,
@@ -4415,7 +4420,7 @@ impl Executor {
 
     #[allow(clippy::too_many_arguments)]
     pub(super) fn open_configured(
-        model: Model,
+        model: impl Into<LoadedModel>,
         context: u32,
         quality: bool,
         prefill_chunk: u32,
@@ -4425,32 +4430,39 @@ impl Executor {
         steering: EngineSteeringSettings,
         expert_profile_path: Option<&str>,
     ) -> Result<Self, String> {
-        match model.shape.family {
+        match model.into() {
-            ModelFamily::DeepSeek => DeepSeekExecutor::open_profile(
+            LoadedModel::Gguf(model) if model.shape.family == ModelFamily::DeepSeek => {
-                model,
+                DeepSeekExecutor::open_profile(
-                context,
+                    *model,
-                quality,
+                    context,
-                prefill_chunk,
+                    quality,
-                power_percent,
+                    prefill_chunk,
-                speculative,
+                    power_percent,
-                ssd,
+                    speculative,
-                steering,
+                    ssd,
-                expert_profile_path,
+                    steering,
-            )
+                    expert_profile_path,
-            .map(Box::new)
+                )
-            .map(Self::DeepSeek),
+                .map(Box::new)
-            ModelFamily::Glm => GlmExecutor::open_profile(
+                .map(Self::DeepSeek)
-                model,
+            }
-                context,
+            LoadedModel::Gguf(model) if model.shape.family == ModelFamily::Glm => {
-                quality,
+                GlmExecutor::open_profile(
-                ssd,
+                    *model,
-                speculative,
+                    context,
-                steering,
+                    quality,
-                expert_profile_path,
+                    ssd,
-            )
+                    speculative,
-            .map(Box::new)
+                    steering,
-            .map(Self::Glm),
+                    expert_profile_path,
-            ModelFamily::Qwen => unreachable!("Qwen uses its dedicated executor"),
+                )
+                .map(Box::new)
+                .map(Self::Glm)
+            }
+            LoadedModel::Gguf(_) => unreachable!("Qwen never uses a GGUF model"),
+            LoadedModel::Qwen(model) => QwenExecutor::open(*model, context)
+                .map(Box::new)
+                .map(Self::Qwen),
         }
     }
 
@@ -4483,6 +4495,10 @@ impl Executor {
                 executor.eval(token)?;
                 Ok(vec![token])
             }
+            Self::Qwen(executor) => {
+                executor.eval(token)?;
+                Ok(vec![token])
+            }
         }
     }
 
@@ -4490,6 +4506,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.eval(token),
             Self::Glm(executor) => executor.eval(token),
+            Self::Qwen(executor) => executor.eval(token),
         }
     }
 
@@ -4499,7 +4516,7 @@ impl Executor {
     ) -> Result<Vec<vision::VisionEmbedding>, String> {
         match self {
             Self::Glm(executor) => executor.encode_visions(encoded),
-            Self::DeepSeek(_) => Err("vision input requires GLM 5.3 Flash".into()),
+            Self::DeepSeek(_) | Self::Qwen(_) => Err("vision input requires GLM 5.3 Flash".into()),
         }
     }
 
@@ -4510,7 +4527,8 @@ impl Executor {
         match self {
             Self::Glm(executor) => executor.set_vision_overlays(overlays),
             Self::DeepSeek(_) if overlays.is_empty() => Ok(()),
-            Self::DeepSeek(_) => Err("vision input requires GLM 5.3 Flash".into()),
+            Self::Qwen(_) if overlays.is_empty() => Ok(()),
+            Self::DeepSeek(_) | Self::Qwen(_) => Err("vision input requires GLM 5.3 Flash".into()),
         }
     }
 
@@ -4529,6 +4547,11 @@ impl Executor {
                 let _ = reasoning;
                 executor.eval_speculative_greedy(token, max_tokens, cancelled)
             }
+            Self::Qwen(executor) => {
+                let _ = (max_tokens, reasoning, cancelled);
+                executor.eval(token)?;
+                Ok(vec![token])
+            }
         }
     }
 
@@ -4540,6 +4563,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.prefill(tokens, progress),
             Self::Glm(executor) => executor.prefill(tokens, progress),
+            Self::Qwen(executor) => executor.prefill(tokens, progress),
         }
     }
 
@@ -4547,6 +4571,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.logits(),
             Self::Glm(executor) => executor.logits(),
+            Self::Qwen(executor) => executor.logits(),
         }
     }
 
@@ -4554,13 +4579,15 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.execution_stats(),
             Self::Glm(executor) => executor.execution_stats(),
+            Self::Qwen(executor) => executor.execution_stats(),
         }
     }
 
-    pub(super) fn model(&self) -> &Model {
+    pub(super) fn model(&self) -> ModelRef<'_> {
         match self {
-            Self::DeepSeek(executor) => executor.model(),
+            Self::DeepSeek(executor) => ModelRef::Gguf(executor.model()),
-            Self::Glm(executor) => executor.model(),
+            Self::Glm(executor) => ModelRef::Gguf(executor.model()),
+            Self::Qwen(executor) => ModelRef::Qwen(executor.model()),
         }
     }
 
@@ -4568,6 +4595,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.context(),
             Self::Glm(executor) => executor.context(),
+            Self::Qwen(executor) => executor.context(),
         }
     }
 
@@ -4575,6 +4603,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.position(),
             Self::Glm(executor) => executor.position(),
+            Self::Qwen(executor) => executor.position(),
         }
     }
 
@@ -4582,6 +4611,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.reset(),
             Self::Glm(executor) => executor.reset(),
+            Self::Qwen(executor) => executor.reset(),
         }
     }
 
@@ -4596,6 +4626,9 @@ impl Executor {
                     Some(ResidentState::Glm(_)) => {
                         return Err("resident session belongs to a different model family".into());
                     }
+                    Some(ResidentState::Qwen(_)) => {
+                        return Err("resident session belongs to a different model family".into());
+                    }
                     None => None,
                 };
                 executor.swap_resident_state(&mut inner)?;
@@ -4607,11 +4640,25 @@ impl Executor {
                     Some(ResidentState::DeepSeek(_)) => {
                         return Err("resident session belongs to a different model family".into());
                     }
+                    Some(ResidentState::Qwen(_)) => {
+                        return Err("resident session belongs to a different model family".into());
+                    }
                     None => None,
                 };
                 executor.swap_resident_state(&mut inner)?;
                 *state = inner.map(|state| ResidentState::Glm(Box::new(state)));
             }
+            Self::Qwen(executor) => {
+                let mut inner = match state.take() {
+                    Some(ResidentState::Qwen(state)) => Some(*state),
+                    Some(ResidentState::DeepSeek(_) | ResidentState::Glm(_)) => {
+                        return Err("resident session belongs to a different model family".into());
+                    }
+                    None => None,
+                };
+                executor.swap_resident_state(&mut inner)?;
+                *state = inner.map(|state| ResidentState::Qwen(Box::new(state)));
+            }
         }
         Ok(())
     }
@@ -4620,6 +4667,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.align_prompt(tokens),
             Self::Glm(executor) => executor.align_prompt(tokens),
+            Self::Qwen(executor) => executor.align_prompt(tokens),
         }
     }
 
@@ -4627,6 +4675,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.tokens(),
             Self::Glm(executor) => executor.tokens(),
+            Self::Qwen(executor) => executor.tokens(),
         }
     }
 
@@ -4634,6 +4683,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.checkpoint_tag(),
             Self::Glm(executor) => executor.checkpoint_tag(),
+            Self::Qwen(executor) => executor.checkpoint_tag(),
         }
     }
 
@@ -4641,6 +4691,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.note_checkpoint_tag(tag),
             Self::Glm(executor) => executor.note_checkpoint_tag(tag),
+            Self::Qwen(executor) => executor.note_checkpoint_tag(tag),
         }
     }
 }

src/engine/metal/checkpoint.rs

@@ -320,6 +320,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.save_checkpoint(path, tag, progress),
             Self::Glm(executor) => executor.save_checkpoint(path, tag, progress),
+            Self::Qwen(executor) => executor.save_checkpoint(path, tag, progress),
         }
     }
 
@@ -331,6 +332,7 @@ impl Executor {
         match self {
             Self::DeepSeek(executor) => executor.load_checkpoint(path, progress),
             Self::Glm(executor) => executor.load_checkpoint(path, progress),
+            Self::Qwen(executor) => executor.load_checkpoint(path, progress),
         }
     }
 }

src/engine/metal/gpu.rs

@@ -5,6 +5,22 @@ pub(super) struct GpuTensor {
     _private: [u8; 0],
 }
 
+#[derive(Clone, Copy)]
+#[repr(C)]
+pub(super) struct QwenWeightView {
+    pub(super) map: *const c_void,
+    pub(super) size: u64,
+    pub(super) offset: u64,
+    pub(super) bytes: u64,
+}
+
+#[derive(Clone, Copy, Default)]
+#[repr(C)]
+pub(super) struct QwenKernelArgs {
+    pub(super) u: [u32; 16],
+    pub(super) f: [f32; 8],
+}
+
 #[derive(Clone, Copy, Default)]
 #[repr(C)]
 pub(super) struct Glm53VisionLayerWeights {
@@ -81,6 +97,18 @@ unsafe extern "C" {
         map_size: u64,
         max_tensor_bytes: u64,
     ) -> i32;
+    pub(super) fn ds4_gpu_qwen_dispatch(
+        kernel: *const c_char,
+        out: *mut GpuTensor,
+        a: *const GpuTensor,
+        b: *const GpuTensor,
+        c: *const GpuTensor,
+        weights: *const QwenWeightView,
+        weight_count: u32,
+        args: *const QwenKernelArgs,
+        grid_x: u32,
+        grid_y: u32,
+    ) -> i32;
     pub(super) fn ds4_gpu_set_transient_model_map_range(
         model_map: *const c_void,
         model_size: u64,
@@ -1804,7 +1832,7 @@ unsafe extern "C" {
 }
 
 pub(super) struct Context {
-    _model_file: File,
+    _model_file: Option<File>,
 }
 
 impl Context {
@@ -1908,9 +1936,29 @@ impl Context {
             }
         }
         Ok(Self {
-            _model_file: model_file,
+            _model_file: Some(model_file),
         })
     }
+
+    pub(super) fn open_qwen(admission_bytes: u64) -> Result<Self, String> {
+        check(unsafe { ds4_gpu_init() }, "Metal initialization")?;
+        unsafe {
+            ds4_gpu_set_glm_model(false);
+            ds4_gpu_set_ssd_streaming(false);
+            ds4_gpu_set_decode_pipeline_fast_lookup(0);
+        }
+        let recommended = unsafe { ds4_gpu_recommended_working_set_size() };
+        if admission_bytes != 0 && recommended != 0 && admission_bytes > recommended {
+            unsafe { ds4_gpu_cleanup() };
+            return Err(format!(
+                "Qwen model load needs {:.1} GiB including context and scratch, but Metal recommends at most {:.1} GiB",
+                admission_bytes as f64 / 1_073_741_824.0,
+                recommended as f64 / 1_073_741_824.0,
+            ));
+        }
+        unsafe { ds4_gpu_set_quality(true) };
+        Ok(Self { _model_file: None })
+    }
 }
 
 impl Drop for Context {

src/engine/qwen.rs

@@ -1,8 +1,13 @@
 use super::tokenizer::Tokenizer;
+use super::{ChatTurn, ModelSummary};
+use crate::model::ModelChoice;
+use crate::settings::ReasoningMode;
+use memmap2::{Mmap, MmapOptions};
 use serde::de::{MapAccess, Visitor};
 use serde::{Deserialize, Deserializer};
 use serde_json::Value;
-use std::collections::{BTreeMap, BTreeSet};
+use sha2::{Digest, Sha256};
+use std::collections::{BTreeMap, BTreeSet, HashMap};
 use std::fmt;
 use std::fs::{self, File};
 use std::io::Read;
@@ -88,6 +93,158 @@ pub(super) struct ArtifactBindings {
     pub(super) mtp: Vec<TensorBinding>,
 }
 
+pub(super) struct QwenMap {
+    path: PathBuf,
+    map: Mmap,
+}
+
+#[derive(Clone)]
+pub(super) struct QwenTensor {
+    pub(super) map: usize,
+    pub(super) name: String,
+    pub(super) dtype: String,
+    pub(super) shape: Vec<u64>,
+    pub(super) quant_bits: Option<u32>,
+    pub(super) group_size: Option<u64>,
+    pub(super) range: std::ops::Range<u64>,
+}
+
+pub(super) struct QwenModel {
+    tokenizer: Tokenizer,
+    memory: MemoryPlan,
+    maps: Vec<QwenMap>,
+    tensors: HashMap<String, QwenTensor>,
+    identity: [u8; 32],
+}
+
+impl QwenModel {
+    pub(super) fn open(root: &Path, context: u32) -> Result<Self, String> {
+        let loaded = load(root, context, false)?;
+        let mut paths = loaded
+            .bindings
+            .core
+            .iter()
+            .map(|binding| binding.file.clone())
+            .collect::<Vec<_>>();
+        paths.sort();
+        paths.dedup();
+        let mut maps = Vec::with_capacity(paths.len());
+        let mut map_indices = HashMap::with_capacity(paths.len());
+        for path in paths {
+            let file = File::open(&path).map_err(|error| format!("{}: {error}", path.display()))?;
+            // SAFETY: verified managed artifacts remain read-only while the model owns each mapping.
+            let map = unsafe { MmapOptions::new().map(&file) }
+                .map_err(|error| format!("cannot map {}: {error}", path.display()))?;
+            map_indices.insert(path.clone(), maps.len());
+            maps.push(QwenMap { path, map });
+        }
+        let tensors = loaded
+            .bindings
+            .core
+            .into_iter()
+            .map(|binding| {
+                let tensor = QwenTensor {
+                    map: map_indices[&binding.file],
+                    name: binding.name.clone(),
+                    dtype: binding.dtype,
+                    shape: binding.shape,
+                    quant_bits: binding.quant_bits,
+                    group_size: binding.group_size,
+                    range: binding.range,
+                };
+                (binding.name, tensor)
+            })
+            .collect::<HashMap<_, _>>();
+        let mut hash = Sha256::new();
+        hash.update(b"DS4Server Qwen3.8 checkpoint identity v1");
+        hash.update(MANIFEST);
+        let identity = hash.finalize().into();
+        Ok(Self {
+            tokenizer: loaded.tokenizer,
+            memory: loaded.memory,
+            maps,
+            tensors,
+            identity,
+        })
+    }
+
+    pub(super) fn tensor(&self, name: &str) -> Result<&QwenTensor, String> {
+        self.tensors
+            .get(name)
+            .ok_or_else(|| format!("Qwen core tensor is missing: {name}"))
+    }
+
+    pub(super) fn map(&self, index: usize) -> (&[u8], &Path) {
+        (&self.maps[index].map, &self.maps[index].path)
+    }
+
+    pub(super) fn checkpoint_identity(&self) -> [u8; 32] {
+        self.identity
+    }
+
+    pub(super) fn summary(&self) -> ModelSummary {
+        ModelSummary {
+            model: ModelChoice::Qwen38FlashNext,
+            mapped_bytes: self.maps.iter().map(|item| item.map.len() as u64).sum(),
+            tensor_count: self.tensors.len(),
+            vocabulary_size: self.tokenizer.vocab_size(),
+            support_loaded: false,
+            vision_loaded: false,
+        }
+    }
+
+    pub(super) fn render_conversation(
+        &self,
+        system: &str,
+        messages: &[ChatTurn],
+        reasoning: ReasoningMode,
+    ) -> Vec<i32> {
+        self.tokenizer
+            .encode_conversation(system, messages, reasoning)
+    }
+
+    pub(super) fn render_history(
+        &self,
+        system: &str,
+        messages: &[ChatTurn],
+        reasoning: ReasoningMode,
+    ) -> Vec<i32> {
+        self.tokenizer.encode_history(system, messages, reasoning)
+    }
+
+    pub(super) fn render_continuation(
+        &self,
+        prompt: &str,
+        reasoning: ReasoningMode,
+        skip_previous_eos: bool,
+    ) -> Vec<i32> {
+        self.tokenizer
+            .encode_continuation(prompt, reasoning, skip_previous_eos)
+    }
+
+    pub(super) fn token_bytes(&self, token: i32) -> Option<Vec<u8>> {
+        self.tokenizer.token_bytes(token)
+    }
+
+    pub(super) fn is_stop_token_for_reasoning(&self, token: i32, reasoning: ReasoningMode) -> bool {
+        self.tokenizer.is_stop(token)
+            || (reasoning == ReasoningMode::Direct
+                && (self.tokenizer.is_think_start(token) || self.tokenizer.is_think_end(token)))
+    }
+
+    pub(super) fn is_think_start_token(&self, token: i32) -> bool {
+        self.tokenizer.is_think_start(token)
+    }
+
+    pub(super) fn is_think_end_token(&self, token: i32) -> bool {
+        self.tokenizer.is_think_end(token)
+    }
+
+    pub(super) fn memory(&self) -> &MemoryPlan {
+        &self.memory
+    }
+}
+
 pub(crate) fn validate_artifacts(root: &Path) -> Result<(), String> {
     load(root, 262_144, true).map(|_| ())
 }