[Session R3] Add routed_experts_start_len for absolute routing slice control (#24851)

Co-authored-by: Byron Hsu <byron@periodiclabs.ai>
Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: zyzshishui <zyzshishui@gmail.com>
Co-authored-by: Yuzhen Zhou <82826991+zyzshishui@users.noreply.github.com>
This commit is contained in:
Byron Hsu
2026-05-10 10:04:43 -07:00
committed by GitHub
co-authored by Byron Hsu Cursor zyzshishui Yuzhen Zhou
parent 9150e77399
commit d82e339ce2
16 changed files with 288 additions and 11 deletions
@@ -374,7 +374,7 @@
"source": [
"#### Returning Routed Experts (MoE Models)\n",
"\n",
"For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`."
"For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`. By default this returns `[0, seqlen - 1)`, the full available sequence, because RL workflows need routed experts for the full sequence. Set `routed_experts_start_len` in `extra_body` to an absolute prefix length to return only `[routed_experts_start_len, seqlen - 1)`. For example, in multi-turn RL rollouts, routed experts for tokens from previous turns have already been collected, so setting this value avoids unnecessary transfer that cause bottlenecks."
]
},
{
@@ -468,7 +468,7 @@
"source": [
"#### Returning Routed Experts (MoE Models)\n",
"\n",
"For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`."
"For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`. By default this returns `[0, seqlen - 1)`, the full available sequence, because RL workflows need routed experts for the full sequence. Set `routed_experts_start_len` in `extra_body` to an absolute prefix length to return only `[routed_experts_start_len, seqlen - 1)`. For example, in multi-turn RL rollouts, routed experts for tokens from previous turns have already been collected, so setting this value avoids unnecessary transfer that cause bottlenecks."
]
},
{
@@ -342,7 +342,7 @@ for chunk in stream:
#### Returning Routed Experts (MoE Models)
For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`.
For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`. By default this returns `[0, seqlen - 1)`, the full available sequence, because RL workflows need routed experts for the full sequence. Set `routed_experts_start_len` in `extra_body` to an absolute prefix length to return only `[routed_experts_start_len, seqlen - 1)`. For example, in multi-turn RL rollouts, routed experts for tokens from previous turns have already been collected, so setting this value avoids unnecessary transfer that cause bottlenecks.
```python Example
# Example with logit_bias parameter for completions API
@@ -406,7 +406,7 @@ print_highlight(f"Response: {response}")
#### Returning Routed Experts (MoE Models)
For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`.
For MoE models, set `return_routed_experts: true` in `extra_body` to return expert routing data. Requires `--enable-return-routed-experts` server flag. The `routed_experts` field will be returned in the `sgl_ext` object on each choice, containing base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`. By default this returns `[0, seqlen - 1)`, the full available sequence, because RL workflows need routed experts for the full sequence. Set `routed_experts_start_len` in `extra_body` to an absolute prefix length to return only `[routed_experts_start_len, seqlen - 1)`. For example, in multi-turn RL rollouts, routed experts for tokens from previous turns have already been collected, so setting this value avoids unnecessary transfer that cause bottlenecks.
## Structured Outputs (JSON, Regex, EBNF)
@@ -107,7 +107,12 @@ The `/generate` endpoint accepts the following parameters in JSON format. For de
<tr>
<td style={{padding: "9px 12px", fontWeight: 500, backgroundColor: "rgba(255,255,255,0.02)"}}>return_routed_experts</td>
<td style={{padding: "9px 12px", backgroundColor: "rgba(255,255,255,0.05)"}}>`bool = False`</td>
<td style={{padding: "9px 12px", backgroundColor: "rgba(255,255,255,0.02)"}}>Whether to return routed experts for MoE models. Requires `--enable-return-routed-experts` server flag. Returns base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`.</td>
<td style={{padding: "9px 12px", backgroundColor: "rgba(255,255,255,0.02)"}}>Whether to return routed experts for MoE models. Requires `--enable-return-routed-experts` server flag. With the default `routed_experts_start_len=0`, returns the full available sequence `[0, seqlen - 1)` because RL workflows need routed experts for the full sequence. The result is base64-encoded int32 expert IDs as a flattened array with logical shape `[num_tokens, num_layers, top_k]`.</td>
</tr>
<tr>
<td style={{padding: "9px 12px", fontWeight: 500, backgroundColor: "rgba(255,255,255,0.02)"}}>routed_experts_start_len</td>
<td style={{padding: "9px 12px", backgroundColor: "rgba(255,255,255,0.05)"}}>`int = 0`</td>
<td style={{padding: "9px 12px", backgroundColor: "rgba(255,255,255,0.02)"}}>If `return_routed_experts`, the absolute start position for returned routed-experts rows. `0` preserves the default full sequence; set it to an accumulated prefix length to return only `[routed_experts_start_len, seqlen - 1)`. For example, in multi-turn RL rollouts, routed experts for tokens from previous turns have already been collected, so setting this value avoids unnecessary transfer that cause bottlenecks. Must be in `[0, prompt_tokens]`.</td>
</tr>
</tbody>
</table>