diff --git a/Cargo.lock b/Cargo.lock
index 1908f060..2b6932a3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -24,7 +24,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
 dependencies = [
  "crypto-common",
- "generic-array",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -87,18 +87,17 @@ dependencies = [
 
 [[package]]
 name = "ai00-core"
-version = "0.5.2"
+version = "0.5.3"
 dependencies = [
  "anyhow",
- "bit-set",
- "bnf_sampler",
  "bytemuck",
  "cbor4ii",
  "derivative",
  "fastrand",
  "flume",
  "half",
- "itertools 0.13.0",
+ "itertools",
+ "kbnf",
  "log",
  "memmap2",
  "qp-trie",
@@ -113,7 +112,7 @@ dependencies = [
 
 [[package]]
 name = "ai00-server"
-version = "0.5.2"
+version = "0.5.3"
 dependencies = [
  "ai00-core",
  "anyhow",
@@ -121,7 +120,7 @@ dependencies = [
  "derivative",
  "flume",
  "futures-util",
- "itertools 0.13.0",
+ "itertools",
  "jsonwebtoken",
  "log",
  "memmap2",
@@ -385,39 +384,7 @@ version = "0.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
 dependencies = [
- "generic-array",
-]
-
-[[package]]
-name = "bnf"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14c09ea5795b3dd735ff47c4b8adf64c46e3ce056fa3c4880b865a352e4c40a2"
-dependencies = [
- "getrandom",
- "nom",
- "rand",
- "serde",
- "serde_json",
-]
-
-[[package]]
-name = "bnf_sampler"
-version = "0.3.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f672b04599d545028652564805fdfbf6c3a035b971ed8006b68cb9c647ef67e7"
-dependencies = [
- "anyhow",
- "bit-set",
- "bnf",
- "itertools 0.12.1",
- "lazy_static",
- "memchr",
- "mimalloc",
- "nohash-hasher",
- "qp-trie",
- "regex",
- "rustc-hash",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -707,7 +674,7 @@ checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
 [[package]]
 name = "converter"
-version = "0.5.2"
+version = "0.5.3"
 dependencies = [
  "anyhow",
  "clap",
@@ -795,7 +762,7 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
  "rand_core",
  "typenum",
 ]
@@ -970,6 +937,12 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9fc0510504f03c51ada170672ac806f1f105a88aa97a5281117e1ddc3368e51a"
 
+[[package]]
+name = "fixedbitset-stack"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d498da3487b4ea426e370276db9e93c29624b667855b415ccd01da983dd1237"
+
 [[package]]
 name = "flate2"
 version = "1.0.30"
@@ -1154,6 +1127,15 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "generic-array"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe739944a5406424e080edccb6add95685130b9f160d5407c639c7df0c5836b0"
+dependencies = [
+ "typenum",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.14"
@@ -1395,6 +1377,15 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "html-escape"
+version = "0.2.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d1ad449764d627e22bfd7cd5e8868264fc9236e07c752972b4080cd351cb476"
+dependencies = [
+ "utf8-width",
+]
+
 [[package]]
 name = "http"
 version = "1.1.0"
@@ -1567,7 +1558,7 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a0c10553d664a4d0bcff9f4215d0aac67a639cc68ef660840afe309b807bc9f5"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -1600,15 +1591,6 @@ version = "1.70.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8478577c03552c21db0e2724ffb8986a5ce7af88107e6be5d2ee6e158c12800"
 
-[[package]]
-name = "itertools"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba291022dbbd398a455acf126c1e341954079855bc60dfdda641363bd6922569"
-dependencies = [
- "either",
-]
-
 [[package]]
 name = "itertools"
 version = "0.13.0"
@@ -1624,6 +1606,18 @@ version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
 
+[[package]]
+name = "jaggedarray"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d18d4d488e472f5e805edd8d7e710c255ff19511e3f5fbb0932932bee0e804d5"
+dependencies = [
+ "generic-array 1.0.0",
+ "num",
+ "tinyvec",
+ "typenum",
+]
+
 [[package]]
 name = "jni-sys"
 version = "0.3.0"
@@ -1663,6 +1657,55 @@ dependencies = [
  "simple_asn1",
 ]
 
+[[package]]
+name = "kbnf"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6d1722638274535080c14a131457152942c92534ed8989980d53aab4cf9da8a"
+dependencies = [
+ "ahash 0.8.11",
+ "displaydoc",
+ "fixedbitset-stack",
+ "jaggedarray",
+ "kbnf-regex-automata",
+ "kbnf-syntax",
+ "nom",
+ "nonmax",
+ "num",
+ "serde",
+ "string-interner",
+ "strum",
+ "thiserror",
+ "tinyvec",
+]
+
+[[package]]
+name = "kbnf-regex-automata"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "499fe4f128763db90782429ea71d01a5503d177d53118589a36e41611286d8a0"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "kbnf-syntax"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ef4c575a961efe76523068d29c9362744f6185e6a8d0de7d4563079fc7e0365b"
+dependencies = [
+ "kbnf-regex-automata",
+ "nom",
+ "parse-hyperlinks",
+ "regex-syntax",
+ "rustc-hash",
+ "serde",
+ "string-interner",
+ "thiserror",
+]
+
 [[package]]
 name = "khronos-egl"
 version = "6.0.0"
@@ -1712,16 +1755,6 @@ dependencies = [
  "windows-targets 0.52.5",
 ]
 
-[[package]]
-name = "libmimalloc-sys"
-version = "0.1.37"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81eb4061c0582dedea1cbc7aff2240300dd6982e0239d1c99e65c1dbf4a30ba7"
-dependencies = [
- "cc",
- "libc",
-]
-
 [[package]]
 name = "linux-raw-sys"
 version = "0.4.13"
@@ -1789,15 +1822,6 @@ dependencies = [
  "paste",
 ]
 
-[[package]]
-name = "mimalloc"
-version = "0.1.41"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f41a2280ded0da56c8cf898babb86e8f10651a34adcfff190ae9a1159c6908d"
-dependencies = [
- "libmimalloc-sys",
-]
-
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -1941,12 +1965,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "nohash-hasher"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2bf50223579dc7cdcfb3bfcacf7069ff68243f8c363f62ffa99cf000a6b9c451"
-
 [[package]]
 name = "nom"
 version = "7.1.3"
@@ -1957,17 +1975,45 @@ dependencies = [
  "minimal-lexical",
 ]
 
+[[package]]
+name = "nonmax"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "610a5acd306ec67f907abe5567859a3c693fb9886eb1f012ab8f2a47bef3db51"
+
+[[package]]
+name = "num"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35bd024e8b2ff75562e5f34e7f4905839deb4b22955ef5e73d2fea1b9813cb23"
+dependencies = [
+ "num-bigint",
+ "num-complex",
+ "num-integer",
+ "num-iter",
+ "num-rational",
+ "num-traits",
+]
+
 [[package]]
 name = "num-bigint"
-version = "0.4.4"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "608e7659b5c3d7cba262d894801b9ec9d00de989e8a82bd4bef91d08da45cdc0"
+checksum = "c165a9ab64cf766f73521c0dd2cfdff64f488b8f0b3e621face3462d3db536d7"
 dependencies = [
- "autocfg",
  "num-integer",
  "num-traits",
 ]
 
+[[package]]
+name = "num-complex"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73f88a1307638156682bada9d7604135552957b7818057dcef22705b4d509495"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "num-conv"
 version = "0.1.0"
@@ -1983,6 +2029,28 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-iter"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1429034a0490724d0075ebb2bc9e875d6503c3cf69e235a8941aa757d83ef5bf"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f83d14da390562dca69fc84082e73e548e1ad308d24accdedd2720017cb37824"
+dependencies = [
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -2117,6 +2185,18 @@ dependencies = [
  "windows-targets 0.52.5",
 ]
 
+[[package]]
+name = "parse-hyperlinks"
+version = "0.23.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0181d37c4d5ae35cc8be7cf823c1a933005661da6a08bcb2855aa392c9a54b8e"
+dependencies = [
+ "html-escape",
+ "nom",
+ "percent-encoding",
+ "thiserror",
+]
+
 [[package]]
 name = "password-hash"
 version = "0.4.2"
@@ -2771,6 +2851,12 @@ dependencies = [
  "untrusted 0.9.0",
 ]
 
+[[package]]
+name = "rustversion"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "955d28af4278de8121b7ebeb796b6a45735dc01436d898801014aced2773a3d6"
+
 [[package]]
 name = "ryu"
 version = "1.0.17"
@@ -3107,9 +3193,9 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.200"
+version = "1.0.203"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddc6f9cc94d67c0e21aaf7eda3a010fd3af78ebf6e096aa6e2e13c79749cce4f"
+checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
 dependencies = [
  "serde_derive",
 ]
@@ -3137,9 +3223,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.200"
+version = "1.0.203"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "856f046b9400cee3c8c94ed572ecdb752444c24528c035cd35882aad6f492bcb"
+checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3322,12 +3408,45 @@ version = "3.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ceb97b7225c713c2fd4db0153cb6b3cab244eb37900c3f634ed4d43310d8c34"
 
+[[package]]
+name = "string-interner"
+version = "0.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1c6a0d765f5807e98a091107bae0a56ea3799f66a5de47b2c84c94a39c09974e"
+dependencies = [
+ "cfg-if",
+ "hashbrown 0.14.5",
+ "serde",
+]
+
 [[package]]
 name = "strsim"
 version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
+[[package]]
+name = "strum"
+version = "0.26.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d8cec3501a5194c432b2b7976db6b7d10ec95c253208b45f83f7136aa985e29"
+dependencies = [
+ "strum_macros",
+]
+
+[[package]]
+name = "strum_macros"
+version = "0.26.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c6bee85a5a24955dc440386795aa378cd9cf82acd5f764469152d2270e581be"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn 2.0.60",
+]
+
 [[package]]
 name = "subtle"
 version = "2.5.0"
@@ -3441,18 +3560,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.59"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0126ad08bff79f29fc3ae6a55cc72352056dfff61e3ff8bb7129476d44b23aa"
+checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.59"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d1cd413b5d558b4c5bf3680e324a6fa5014e7b7c067a51e69dbdf47eb7148b66"
+checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3848,6 +3967,12 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09cc8ee72d2a9becf2f2febe0205bbed8fc6615b7cb429ad062dc7b7ddd036a9"
 
+[[package]]
+name = "utf8-width"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86bd8d4e895da8537e5315b8254664e6b769c4ff3db18321b297a1e7004392e3"
+
 [[package]]
 name = "utf8parse"
 version = "0.2.1"
@@ -3988,9 +4113,9 @@ dependencies = [
 
 [[package]]
 name = "web-rwkv"
-version = "0.8.11"
+version = "0.8.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a8974a3084c612cc10e0d7e1b7f947b9951360f322977f6f9d344e7271e99a97"
+checksum = "cf8c1d41f4ca9a792c17e1744a38646282fce55de19936fbaf7017b88691794e"
 dependencies = [
  "ahash 0.8.11",
  "anyhow",
@@ -4002,7 +4127,7 @@ dependencies = [
  "gpp",
  "half",
  "instant",
- "itertools 0.13.0",
+ "itertools",
  "log",
  "regex",
  "rustc-hash",
@@ -4065,9 +4190,9 @@ dependencies = [
 
 [[package]]
 name = "wgpu"
-version = "0.20.0"
+version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32ff1bfee408e1028e2e3acbf6d32d98b08a5a059ccbf5f33305534453ba5d3e"
+checksum = "90e37c7b9921b75dfd26dd973fdcbce36f13dfa6e2dc82aece584e0ed48c355c"
 dependencies = [
  "arrayvec",
  "cfg-if",
@@ -4091,9 +4216,9 @@ dependencies = [
 
 [[package]]
 name = "wgpu-core"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac6a86eaa5e763e59c73cf9e97d55fffd4dfda69fd8bda19589fcf851ddfef1f"
+checksum = "d59e0d5fc509601c69e4e1fa06c1eb3c4c9f12956a5e30c79b61ef1c1be7daf0"
 dependencies = [
  "arrayvec",
  "bit-vec",
@@ -4118,9 +4243,9 @@ dependencies = [
 
 [[package]]
 name = "wgpu-hal"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d71c8ae05170583049b65ee562fd839fdc0b3e9ddb84f4e40c9d5f8ea0d4c8c"
+checksum = "6aa24c3889f885a3fb9133b454c8418bfcfaadcfe4ed3be96ac80e76703b863b"
 dependencies = [
  "android_system_properties",
  "arrayvec",
diff --git a/Cargo.toml b/Cargo.toml
index 68a645a9..b2479de9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,7 @@ keywords = ["LLM", "deep-learning", "model", "rwkv"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/cgisky1980/ai00_rwkv_server"
 rust-version = "1.76"
-version = "0.5.2"
+version = "0.5.3"
 
 [workspace.dependencies]
 anyhow = "1"
@@ -34,7 +34,7 @@ path = "crates/ai00-core"
 # path = "../web-rwkv"
 default-features = false
 features = ["native"]
-version = "0.8.11"
+version = "0.8.12"
 
 [profile.release]
 lto = false
diff --git a/crates/ai00-core/Cargo.toml b/crates/ai00-core/Cargo.toml
index d0184956..f3a3c119 100644
--- a/crates/ai00-core/Cargo.toml
+++ b/crates/ai00-core/Cargo.toml
@@ -12,12 +12,11 @@ rust-version.workspace = true
 version.workspace = true
 
 [dependencies]
-bit-set = "0.5.3"
-bnf_sampler = "0.3.7"
 bytemuck = "1"
 cbor4ii = { version = "0.3.2", features = ["serde1"] }
 fastrand = "2"
 half = "2.4"
+kbnf = "0.1.2"
 qp-trie = "0.8"
 rustc-hash = "1.1.0"
 uuid = { version = "1.8.0", features = ["serde", "v4"] }
diff --git a/crates/ai00-core/src/lib.rs b/crates/ai00-core/src/lib.rs
index 54725627..ec4dc5ee 100644
--- a/crates/ai00-core/src/lib.rs
+++ b/crates/ai00-core/src/lib.rs
@@ -5,7 +5,6 @@ use std::{
 };
 
 use anyhow::{anyhow, bail, Result};
-use bnf_sampler::{utils::U8ArrayWrapper, vocabulary::Vocabulary};
 use derivative::Derivative;
 use flume::{Receiver, Sender};
 use half::f16;
@@ -267,24 +266,6 @@ async fn load_tokenizer(path: impl AsRef<Path>) -> Result<Tokenizer> {
     Ok(Tokenizer::new(&contents)?)
 }
 
-fn load_vocab(tokenizer: &Tokenizer) -> Vocabulary {
-    let vocab = tokenizer.bytes_to_token_index();
-    let token_to_id = vocab
-        .iter()
-        .map(|(k, v)| (U8ArrayWrapper(k.clone().into_boxed_slice()), *v as u32))
-        .collect();
-    let id_to_token = vocab.iter().map(|(k, v)| (*v as u32, k.clone())).collect();
-    let id_to_token_string = vocab
-        .iter()
-        .map(|(k, v)| (*v as u32, String::from_utf8_lossy(k).to_string()))
-        .collect();
-    Vocabulary {
-        token_to_id,
-        id_to_token,
-        id_to_token_string,
-    }
-}
-
 async fn load_init_state<R: Reader>(
     context: &Context,
     info: &ModelInfo,
@@ -317,7 +298,6 @@ async fn load_runtime(
     } = reload.clone();
 
     let tokenizer = load_tokenizer(tokenizer_path).await?;
-    let vocab = load_vocab(&tokenizer);
 
     let file = File::open(model_path).await?;
     let data = unsafe { Mmap::map(&file) }?;
@@ -406,7 +386,7 @@ async fn load_runtime(
                             ($version, $precision) => {
                                 let model = Build::<$model>::build(builder).await?;
                                 let builder = <$runtime>::new(model, max_batch);
-                                Runtime::new(context, builder, reload, states, tokenizer, vocab).await
+                                Runtime::new(context, builder, reload, states, tokenizer).await
                             }
                         )+
                     }
@@ -441,7 +421,7 @@ async fn load_runtime(
                                 let seed: Seed<_, $model> = Seed::new(&context);
                                 let model = seed.deserialize(&mut deserializer)?;
                                 let builder = <$runtime>::new(model, reload.max_batch);
-                                Runtime::new(context, builder, reload, states, tokenizer, vocab).await
+                                Runtime::new(context, builder, reload, states, tokenizer).await
                             }
                         )+
                     }
diff --git a/crates/ai00-core/src/run.rs b/crates/ai00-core/src/run.rs
index 9c06f894..aee164b9 100644
--- a/crates/ai00-core/src/run.rs
+++ b/crates/ai00-core/src/run.rs
@@ -8,7 +8,6 @@ use std::{
 };
 
 use anyhow::Result;
-use bnf_sampler::{grammar::Grammar, vocabulary::Vocabulary};
 use derivative::Derivative;
 use flume::{Receiver, Sender};
 use itertools::Itertools;
@@ -36,8 +35,6 @@ use crate::{
 const END_OF_LINE_TOKEN: u16 = 261;
 const MIN_PROMPT_CACHE_TOKENS: usize = 32;
 const MAX_CACHE_ITEMS: usize = 256;
-const SAMPLER_ARENA_CAPACITY: usize = 1048576;
-const GRAMMAR_ARENA_CAPACITY: usize = 1024;
 
 #[derive(Debug)]
 pub enum SlotResult {
@@ -401,7 +398,6 @@ pub struct Runtime {
     model: Arc<dyn ModelSerialize + Send + Sync>,
     runtime: JobRuntime<InferInput, InferOutput>,
     tokenizer: Arc<Tokenizer>,
-    vocab: Arc<Vocabulary>,
     slots: Mutex<Vec<SlotState>>,
     caches: Mutex<CacheHub>,
 }
@@ -413,7 +409,6 @@ impl Runtime {
         reload: ReloadRequest,
         states: Vec<InitState>,
         tokenizer: Tokenizer,
-        vocab: Vocabulary,
     ) -> Self
     where
         J: Job<Info = InferInfo, Input = InferChunk, Output = InferOutput>,
@@ -441,7 +436,7 @@ impl Runtime {
         let info = builder.info();
         let state = Arc::new(builder.state());
         let model = Arc::new(Model(builder.model()));
-        let runtime = JobRuntime::new(builder).await;
+        let runtime = JobRuntime::<InferInput, InferOutput>::new(builder).await;
 
         Self {
             context,
@@ -451,7 +446,6 @@ impl Runtime {
             model,
             runtime,
             tokenizer: Arc::new(tokenizer),
-            vocab: Arc::new(vocab),
             slots: Mutex::new(slots),
             caches: Mutex::new(caches),
         }
@@ -571,16 +565,7 @@ impl Runtime {
 
     /// Compile and cache the given schema into a BNF sampler.
     async fn compile_bnf_schema(&self, schema: String) -> Result<BnfSampler> {
-        let grammar = Grammar::new(&schema, self.vocab.clone(), GRAMMAR_ARENA_CAPACITY)?;
-        let start_nonterminal = self.reload.bnf.start_nonterminal.clone();
-        let sampler = bnf_sampler::sampler::Sampler::new(
-            grammar,
-            start_nonterminal,
-            self.vocab.clone(),
-            SAMPLER_ARENA_CAPACITY,
-            self.reload.bnf.enable_bytes_cache,
-        )?;
-        Ok(BnfSampler::new(sampler))
+        BnfSampler::new(&self.tokenizer, &schema)
     }
 
     /// Queue an inference task.
@@ -950,10 +935,10 @@ impl Runtime {
             };
 
             // update the transformer (BNF) state
-            let mut exhausted = false;
+            let mut halt = false;
             for transformer in context.transformers.iter() {
                 let mut transformer = transformer.write().await;
-                exhausted |= transformer.update(token);
+                halt |= transformer.update(token);
             }
 
             // here we detect if there is a stop word in our buffer
@@ -1045,7 +1030,7 @@ impl Runtime {
                 }
                 let _ = context.sender.send(Token::Choose(perplexities));
                 done = true;
-            } else if exhausted || stop_matched {
+            } else if halt || stop_matched {
                 let output = String::from_utf8_lossy(head);
                 let _ = context.sender.send(Token::Content(output.into()));
                 stop(FinishReason::Stop);
diff --git a/crates/ai00-core/src/sampler/bnf.rs b/crates/ai00-core/src/sampler/bnf.rs
index df490aa8..bb048db1 100644
--- a/crates/ai00-core/src/sampler/bnf.rs
+++ b/crates/ai00-core/src/sampler/bnf.rs
@@ -1,65 +1,46 @@
-use bit_set::BitSet;
-use bnf_sampler::sampler::{AcceptTokenResult, PossibleTokensResult, Sampler};
+use anyhow::Result;
+use kbnf::{
+    engine_like::AcceptTokenError, AcceptTokenResult, Engine, EngineLike, Token, Vocabulary,
+};
+use web_rwkv::tokenizer::Tokenizer;
 
 use super::Transformer;
 
 #[derive(Debug)]
-pub struct BnfSampler {
-    sampler: Sampler,
-    current_token_ids: BitSet,
-}
+pub struct BnfSampler(Engine);
 
 impl BnfSampler {
-    pub fn new(mut sampler: Sampler) -> Self {
-        let current_token_ids = match sampler.all_possible_next_tokens(None) {
-            Ok(PossibleTokensResult::Continue(tokens)) => tokens.clone(),
-            _ => BitSet::new(),
-        };
-        Self {
-            sampler,
-            current_token_ids,
-        }
-    }
-
-    #[inline]
-    pub fn current_token_ids(&self) -> &BitSet {
-        &self.current_token_ids
-    }
-}
-
-impl std::ops::Deref for BnfSampler {
-    type Target = Sampler;
-
-    fn deref(&self) -> &Self::Target {
-        &self.sampler
-    }
-}
-
-impl std::ops::DerefMut for BnfSampler {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.sampler
+    pub fn new(tokenizer: &Tokenizer, schema: &str) -> Result<Self> {
+        let tokens = tokenizer
+            .token_index_to_bytes()
+            .iter()
+            .enumerate()
+            .map(|(k, v)| (k as u32, Token(v.clone().into_boxed_slice())))
+            .collect();
+        let strings = tokenizer
+            .token_index_to_bytes()
+            .iter()
+            .enumerate()
+            .map(|(k, v)| (k as u32, String::from_utf8_lossy(v).to_string()))
+            .collect();
+        let vocab = Vocabulary::new(tokens, strings)?;
+        let engine = Engine::new(schema, vocab)?;
+        Ok(Self(engine))
     }
 }
 
 impl Transformer for BnfSampler {
     fn transform(&self, output: &mut [f32]) {
-        output
-            .iter_mut()
-            .enumerate()
-            .filter(|&(token, _)| !self.current_token_ids().contains(token))
-            .for_each(|(_, logits)| *logits = f32::MIN)
+        self.0.mask_logits(output).expect("bnf transform error")
     }
 
     fn update(&mut self, token: u16) -> bool {
-        let token = Some(token as u32);
-        let accept = self.accept_a_token(token).expect("invalid input token");
-        self.current_token_ids = match self.sampler.all_possible_next_tokens(None) {
-            Ok(PossibleTokensResult::Continue(tokens)) => tokens.clone(),
-            _ => BitSet::new(),
+        let halt = match self.0.try_accept_new_token(token as u32) {
+            Ok(AcceptTokenResult::Finished) | Err(AcceptTokenError::Finished) => true,
+            Ok(AcceptTokenResult::Ongoing) => false,
+            Err(_) => self.0.is_finished(),
         };
-        match accept {
-            AcceptTokenResult::Continue => false,
-            AcceptTokenResult::End | AcceptTokenResult::Failed => true,
-        }
+        self.0.compute_allowed_token_ids();
+        halt
     }
 }