diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 5b19eb8c..29ff6d45 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -41,6 +41,10 @@ jobs:
           components: rustfmt, clippy
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+      - name: Clean unused files
+        run: |
+          sudo rm -rf /usr/local/lib/android # will release about 10 GB if you don't need Android
+          sudo rm -rf /usr/share/dotnet # will release about 20GB if you don't need .NET
       - name: Install sccache
         run: |
           curl -fsSL https://github.com/mozilla/sccache/releases/download/v$SCCACHE/sccache-v$SCCACHE-x86_64-unknown-linux-musl.tar.gz | tar -xzv --strip-components=1 -C /usr/local/bin sccache-v$SCCACHE-x86_64-unknown-linux-musl/sccache
diff --git a/Cargo.lock b/Cargo.lock
index f8151731..ccccdf3c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -24,7 +24,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42cd52102d3df161c77a887b608d7a4897d7cc112886a9537b738a887a03aaff"
 dependencies = [
  "cfg-if",
+ "getrandom",
  "once_cell",
+ "serde",
  "version_check",
  "zerocopy",
 ]
@@ -265,6 +267,21 @@ version = "0.21.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
 
+[[package]]
+name = "bit-set"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0700ddab506f33b20a03b13996eccd309a48e5ff77d0d95926aa0210fb4e95f1"
+dependencies = [
+ "bit-vec",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "349f9b6a179ed607305526ca489b34ad0a41aed5f7980fa90eb03160b69598fb"
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -716,6 +733,16 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "fancy-regex"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b95f7c0680e4142284cf8b22c14a476e87d61b004a3a0861872b32ef7ead40a2"
+dependencies = [
+ "bit-set",
+ "regex",
+]
+
 [[package]]
 name = "fastrand"
 version = "2.0.1"
@@ -780,6 +807,16 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "fraction"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3027ae1df8d41b4bed2241c8fdad4acc1e7af60c8e17743534b545e77182d678"
+dependencies = [
+ "lazy_static",
+ "num",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.30"
@@ -895,8 +932,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "190092ea657667030ac6a35e305e62fc4dd69fd98ac98631e5d3a2b1575a12b5"
 dependencies = [
  "cfg-if",
+ "js-sys",
  "libc",
  "wasi",
+ "wasm-bindgen",
 ]
 
 [[package]]
@@ -1181,6 +1220,15 @@ version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f518f335dce6725a761382244631d86cf0ccb2863413590b31338feb467f9c3"
 
+[[package]]
+name = "iso8601"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "924e5d73ea28f59011fec52a0d12185d496a9b075d360657aed2a5707f701153"
+dependencies = [
+ "nom",
+]
+
 [[package]]
 name = "itertools"
 version = "0.10.5"
@@ -1223,6 +1271,36 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "jsonschema"
+version = "0.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a071f4f7efc9a9118dfb627a0a94ef247986e1ab8606a4c806ae2b3aa3b6978"
+dependencies = [
+ "ahash",
+ "anyhow",
+ "base64 0.21.7",
+ "bytecount",
+ "clap",
+ "fancy-regex",
+ "fraction",
+ "getrandom",
+ "iso8601",
+ "itoa",
+ "memchr",
+ "num-cmp",
+ "once_cell",
+ "parking_lot",
+ "percent-encoding",
+ "regex",
+ "reqwest",
+ "serde",
+ "serde_json",
+ "time",
+ "url",
+ "uuid",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -1574,12 +1652,84 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b05180d69e3da0e530ba2a1dae5110317e49e3b7f3d41be227dc5f92e49ee7af"
+dependencies = [
+ "num-bigint",
+ "num-complex",
+ "num-integer",
+ "num-iter",
+ "num-rational",
+ "num-traits",
+]
+
+[[package]]
+name = "num-bigint"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "608e7659b5c3d7cba262d894801b9ec9d00de989e8a82bd4bef91d08da45cdc0"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-cmp"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63335b2e2c34fae2fb0aa2cecfd9f0832a1e24b3b32ecec612c3426d46dc8aaa"
+
+[[package]]
+name = "num-complex"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23c6602fda94a57c990fe0df199a035d83576b496aa29f4e634a8ac6004e68a6"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "num-conv"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "51d515d32fb182ee37cda2ccdcb92950d6a3c2893aa280e540671c2cd0f3b1d9"
 
+[[package]]
+name = "num-integer"
+version = "0.1.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7969661fd2958a5cb096e56c8e1ad0444ac2bbcd0061bd28660485a44879858f"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "num-iter"
+version = "0.1.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d869c01cc0c455284163fd0092f1f93835385ccab5a98a0dcc497b2f8bf055a9"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0638a1c9d0a3c0914158145bc76cff373a75a627e6ecbfb71cbe6f453a5a19b0"
+dependencies = [
+ "autocfg",
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.18"
@@ -2874,6 +3024,7 @@ dependencies = [
  "futures-util",
  "hf-hub",
  "init-tracing-opentelemetry",
+ "jsonschema",
  "metrics",
  "metrics-exporter-prometheus",
  "minijinja",
@@ -3530,6 +3681,12 @@ dependencies = [
  "zip",
 ]
 
+[[package]]
+name = "uuid"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f00cc9702ca12d3c81455259621e676d0f7251cec66a21e98fe2e9a37db93b2a"
+
 [[package]]
 name = "valuable"
 version = "0.1.0"
diff --git a/docs/openapi.json b/docs/openapi.json
index d72d32e9..fad01aec 100644
--- a/docs/openapi.json
+++ b/docs/openapi.json
@@ -1022,6 +1022,57 @@
           }
         }
       },
+      "GrammarType": {
+        "oneOf": [
+          {
+            "type": "object",
+            "required": [
+              "type",
+              "value"
+            ],
+            "properties": {
+              "type": {
+                "type": "string",
+                "enum": [
+                  "json"
+                ]
+              },
+              "value": {
+                "type": "string",
+                "description": "A string that represents a [JSON Schema](https://json-schema.org/).\n\nJSON Schema is a declarative language that allows to annotate JSON documents\nwith types and descriptions.",
+                "example": {
+                  "properties": {
+                    "location": {
+                      "type": "string"
+                    }
+                  }
+                }
+              }
+            }
+          },
+          {
+            "type": "object",
+            "required": [
+              "type",
+              "value"
+            ],
+            "properties": {
+              "type": {
+                "type": "string",
+                "enum": [
+                  "regex"
+                ]
+              },
+              "value": {
+                "type": "string"
+              }
+            }
+          }
+        ],
+        "discriminator": {
+          "propertyName": "type"
+        }
+      },
       "Info": {
         "type": "object",
         "required": [
diff --git a/integration-tests/models/__snapshots__/test_grammar_llama/test_flash_llama_grammar_json.json b/integration-tests/models/__snapshots__/test_grammar_llama/test_flash_llama_grammar_json.json
index 7b12b158..d7fb620d 100644
--- a/integration-tests/models/__snapshots__/test_grammar_llama/test_flash_llama_grammar_json.json
+++ b/integration-tests/models/__snapshots__/test_grammar_llama/test_flash_llama_grammar_json.json
@@ -135,129 +135,129 @@
         "special": false,
         "text": "\",\""
       },
-      {
-        "id": 4230,
-        "logprob": -0.020492554,
-        "special": false,
-        "text": "last"
-      },
-      {
-        "id": 1170,
-        "logprob": -0.0013818741,
-        "special": false,
-        "text": "Name"
-      },
-      {
-        "id": 4710,
-        "logprob": -0.0067749023,
-        "special": false,
-        "text": "\":\""
-      },
-      {
-        "id": 29950,
-        "logprob": -0.11578369,
-        "special": false,
-        "text": "H"
-      },
-      {
-        "id": 14339,
-        "logprob": -0.004131317,
-        "special": false,
-        "text": "olt"
-      },
-      {
-        "id": 29920,
-        "logprob": -0.0033359528,
-        "special": false,
-        "text": "z"
-      },
-      {
-        "id": 3284,
-        "logprob": -0.20471191,
-        "special": false,
-        "text": "\",\""
-      },
       {
         "id": 29882,
-        "logprob": -0.0069274902,
+        "logprob": -0.08862305,
         "special": false,
         "text": "h"
       },
       {
-        "id": 20838,
-        "logprob": -0.19580078,
+        "id": 711,
+        "logprob": -0.66259766,
         "special": false,
-        "text": "obb"
+        "text": "ob"
       },
       {
-        "id": 29891,
-        "logprob": -2.2649765e-06,
+        "id": 1609,
+        "logprob": -5.51939e-05,
         "special": false,
-        "text": "y"
+        "text": "by"
       },
       {
         "id": 4710,
-        "logprob": -0.32080078,
+        "logprob": -0.23120117,
         "special": false,
         "text": "\":\""
       },
       {
         "id": 29911,
-        "logprob": -2.1035156,
+        "logprob": -2.3730469,
         "special": false,
         "text": "T"
       },
       {
         "id": 11003,
-        "logprob": -0.020767212,
+        "logprob": -0.032104492,
         "special": false,
         "text": "rees"
       },
       {
         "id": 3284,
-        "logprob": -0.6010742,
+        "logprob": -0.22021484,
+        "special": false,
+        "text": "\",\""
+      },
+      {
+        "id": 4230,
+        "logprob": -0.06726074,
+        "special": false,
+        "text": "last"
+      },
+      {
+        "id": 1170,
+        "logprob": -0.003501892,
+        "special": false,
+        "text": "Name"
+      },
+      {
+        "id": 4710,
+        "logprob": -0.0045661926,
+        "special": false,
+        "text": "\":\""
+      },
+      {
+        "id": 29950,
+        "logprob": -0.12512207,
+        "special": false,
+        "text": "H"
+      },
+      {
+        "id": 14339,
+        "logprob": -0.009552002,
+        "special": false,
+        "text": "olt"
+      },
+      {
+        "id": 29920,
+        "logprob": -0.00042438507,
+        "special": false,
+        "text": "z"
+      },
+      {
+        "id": 3284,
+        "logprob": -0.11651611,
         "special": false,
         "text": "\",\""
       },
       {
         "id": 29876,
-        "logprob": -0.57666016,
+        "logprob": -0.29736328,
         "special": false,
         "text": "n"
       },
       {
         "id": 398,
-        "logprob": -0.0061073303,
+        "logprob": -0.003030777,
         "special": false,
         "text": "um"
       },
       {
         "id": 29907,
-        "logprob": -0.45703125,
+        "logprob": -0.3774414,
         "special": false,
         "text": "C"
       },
       {
         "id": 1446,
-        "logprob": -0.0002872944,
+        "logprob": -0.0003130436,
         "special": false,
         "text": "ats"
       },
       {
         "id": 1115,
-        "logprob": -0.0021018982,
+        "logprob": -0.0021514893,
         "special": false,
         "text": "\":"
       },
       {
         "id": 29906,
-        "logprob": -0.08996582,
+        "logprob": -0.071899414,
         "special": false,
         "text": "2"
       },
       {
         "id": 29913,
-        "logprob": -0.021697998,
+        "logprob": -0.018997192,
         "special": false,
         "text": "}"
       },
@@ -270,5 +270,5 @@
     ],
     "top_tokens": null
   },
-  "generated_text": "{\"firstName\":\"David\",\"lastName\":\"Holtz\",\"hobby\":\"Trees\",\"numCats\":2}"
+  "generated_text": "{\"firstName\":\"David\",\"hobby\":\"Trees\",\"lastName\":\"Holtz\",\"numCats\":2}"
 }
diff --git a/integration-tests/models/test_flash_awq.py b/integration-tests/models/test_flash_awq.py
index 62a95f48..ead918c3 100644
--- a/integration-tests/models/test_flash_awq.py
+++ b/integration-tests/models/test_flash_awq.py
@@ -18,7 +18,6 @@ async def flash_llama_awq(flash_llama_awq_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_awq(flash_llama_awq, response_snapshot):
     response = await flash_llama_awq.generate(
         "What is Deep Learning?", max_new_tokens=10, decoder_input_details=True
@@ -33,7 +32,6 @@ async def test_flash_llama_awq(flash_llama_awq, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_awq_all_params(flash_llama_awq, response_snapshot):
     response = await flash_llama_awq.generate(
         "What is Deep Learning?",
@@ -55,7 +53,6 @@ async def test_flash_llama_awq_all_params(flash_llama_awq, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_awq_load(flash_llama_awq, generate_load, response_snapshot):
     responses = await generate_load(
         flash_llama_awq, "What is Deep Learning?", max_new_tokens=10, n=4
diff --git a/integration-tests/models/test_flash_awq_sharded.py b/integration-tests/models/test_flash_awq_sharded.py
index 1c687fc9..a83614ac 100644
--- a/integration-tests/models/test_flash_awq_sharded.py
+++ b/integration-tests/models/test_flash_awq_sharded.py
@@ -18,7 +18,6 @@ async def flash_llama_awq_sharded(flash_llama_awq_handle_sharded):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_awq_sharded(flash_llama_awq_sharded, response_snapshot):
     response = await flash_llama_awq_sharded.generate(
         "What is Deep Learning?", max_new_tokens=10, decoder_input_details=True
@@ -33,7 +32,6 @@ async def test_flash_llama_awq_sharded(flash_llama_awq_sharded, response_snapsho
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_awq_load_sharded(
     flash_llama_awq_sharded, generate_load, response_snapshot
 ):
diff --git a/integration-tests/models/test_flash_medusa.py b/integration-tests/models/test_flash_medusa.py
index a0ce0570..e0cc1039 100644
--- a/integration-tests/models/test_flash_medusa.py
+++ b/integration-tests/models/test_flash_medusa.py
@@ -14,7 +14,6 @@ async def flash_medusa(flash_medusa_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_medusa_simple(flash_medusa, response_snapshot):
     response = await flash_medusa.generate(
         "What is Deep Learning?", max_new_tokens=10, decoder_input_details=True
@@ -25,7 +24,6 @@ async def test_flash_medusa_simple(flash_medusa, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_medusa_all_params(flash_medusa, response_snapshot):
     response = await flash_medusa.generate(
         "What is Deep Learning?",
@@ -48,7 +46,6 @@ async def test_flash_medusa_all_params(flash_medusa, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_medusa_load(flash_medusa, generate_load, response_snapshot):
     responses = await generate_load(
         flash_medusa, "What is Deep Learning?", max_new_tokens=10, n=4
diff --git a/integration-tests/models/test_flash_mistral.py b/integration-tests/models/test_flash_mistral.py
index ace3328b..52b51928 100644
--- a/integration-tests/models/test_flash_mistral.py
+++ b/integration-tests/models/test_flash_mistral.py
@@ -14,7 +14,6 @@ async def flash_mistral(flash_mistral_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_mistral(flash_mistral, response_snapshot):
     response = await flash_mistral.generate(
         "Test request", max_new_tokens=10, decoder_input_details=True
@@ -26,7 +25,6 @@ async def test_flash_mistral(flash_mistral, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_mistral_all_params(flash_mistral, response_snapshot):
     response = await flash_mistral.generate(
         "Test request",
@@ -49,7 +47,6 @@ async def test_flash_mistral_all_params(flash_mistral, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_mistral_load(flash_mistral, generate_load, response_snapshot):
     responses = await generate_load(
         flash_mistral, "Test request", max_new_tokens=10, n=4
diff --git a/integration-tests/models/test_flash_phi.py b/integration-tests/models/test_flash_phi.py
index 0987b3a1..9d6ca566 100644
--- a/integration-tests/models/test_flash_phi.py
+++ b/integration-tests/models/test_flash_phi.py
@@ -14,7 +14,6 @@ async def flash_phi(flash_phi_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_phi(flash_phi, response_snapshot):
     response = await flash_phi.generate(
         "Test request", max_new_tokens=10, decoder_input_details=True
@@ -26,7 +25,6 @@ async def test_flash_phi(flash_phi, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_phi_all_params(flash_phi, response_snapshot):
     response = await flash_phi.generate(
         "Test request",
@@ -50,7 +48,6 @@ async def test_flash_phi_all_params(flash_phi, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_phi_load(flash_phi, generate_load, response_snapshot):
     responses = await generate_load(flash_phi, "Test request", max_new_tokens=10, n=4)
 
diff --git a/integration-tests/models/test_flash_starcoder_gptq.py b/integration-tests/models/test_flash_starcoder_gptq.py
index 5e448d55..329158b7 100644
--- a/integration-tests/models/test_flash_starcoder_gptq.py
+++ b/integration-tests/models/test_flash_starcoder_gptq.py
@@ -14,7 +14,6 @@ async def flash_starcoder_gptq(flash_starcoder_gptq_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_starcoder_gptq(flash_starcoder_gptq, generous_response_snapshot):
     response = await flash_starcoder_gptq.generate(
         "def geometric_mean(L: List[float]):",
@@ -26,7 +25,6 @@ async def test_flash_starcoder_gptq(flash_starcoder_gptq, generous_response_snap
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_starcoder_gptq_default_params(
     flash_starcoder_gptq, generous_response_snapshot
 ):
@@ -43,7 +41,6 @@ async def test_flash_starcoder_gptq_default_params(
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_starcoder_gptq_load(
     flash_starcoder_gptq, generate_load, generous_response_snapshot
 ):
diff --git a/integration-tests/models/test_grammar_llama.py b/integration-tests/models/test_grammar_llama.py
index f068496c..585d0656 100644
--- a/integration-tests/models/test_grammar_llama.py
+++ b/integration-tests/models/test_grammar_llama.py
@@ -19,7 +19,6 @@ async def flash_llama_grammar(flash_llama_grammar_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_grammar(flash_llama_grammar, response_snapshot):
     response = await flash_llama_grammar.generate(
         "Test request", max_new_tokens=10, decoder_input_details=True
@@ -30,7 +29,6 @@ async def test_flash_llama_grammar(flash_llama_grammar, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_grammar_regex(flash_llama_grammar, response_snapshot):
     response = await flash_llama_grammar.generate(
         "Whats Googles DNS",
@@ -49,7 +47,6 @@ async def test_flash_llama_grammar_regex(flash_llama_grammar, response_snapshot)
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_grammar_json(flash_llama_grammar, response_snapshot):
     response = await flash_llama_grammar.generate(
         "info: david holtz like trees and has two cats. ",
@@ -92,13 +89,12 @@ async def test_flash_llama_grammar_json(flash_llama_grammar, response_snapshot):
     assert response.details.generated_tokens == 30
     assert (
         response.generated_text
-        == '{"firstName":"David","lastName":"Holtz","hobby":"Trees","numCats":2}'
+        == '{"firstName":"David","hobby":"Trees","lastName":"Holtz","numCats":2}'
     )
     assert response == response_snapshot
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_grammar_load(
     flash_llama_grammar, generate_load, response_snapshot
 ):
@@ -130,7 +126,6 @@ async def test_flash_llama_grammar_load(
 # this is the same as the above test, but only fires off a single request
 # this is only to ensure that the parallel and single inference produce the same result
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_flash_llama_grammar_single_load_instance(
     flash_llama_grammar, generate_load, response_snapshot
 ):
diff --git a/integration-tests/models/test_mamba.py b/integration-tests/models/test_mamba.py
index 5ec2ec31..bf3701b4 100644
--- a/integration-tests/models/test_mamba.py
+++ b/integration-tests/models/test_mamba.py
@@ -14,7 +14,6 @@ async def fused_kernel_mamba(fused_kernel_mamba_handle):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_mamba(fused_kernel_mamba, response_snapshot):
     response = await fused_kernel_mamba.generate(
         "What is Deep Learning?", max_new_tokens=10
@@ -26,7 +25,6 @@ async def test_mamba(fused_kernel_mamba, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_mamba_all_params(fused_kernel_mamba, response_snapshot):
     response = await fused_kernel_mamba.generate(
         "blue, red, yellow, ",
@@ -53,7 +51,6 @@ async def test_mamba_all_params(fused_kernel_mamba, response_snapshot):
 
 
 @pytest.mark.asyncio
-@pytest.mark.private
 async def test_mamba_load(
     fused_kernel_mamba, generate_load, generous_response_snapshot
 ):
diff --git a/router/Cargo.toml b/router/Cargo.toml
index 7d6dc017..170debda 100644
--- a/router/Cargo.toml
+++ b/router/Cargo.toml
@@ -22,6 +22,7 @@ text-generation-client = { path = "client" }
 clap = { version = "4.4.5", features = ["derive", "env"] }
 futures = "0.3.28"
 hf-hub = { version = "0.3.0", features = ["tokio"] }
+jsonschema = { version = "0.17.1", features = ["draft202012"] }
 metrics = "0.21.1"
 metrics-exporter-prometheus = { version = "0.12.1", features = [] }
 nohash-hasher = "0.2.0"
diff --git a/router/src/lib.rs b/router/src/lib.rs
index b7285e65..c6928a5a 100644
--- a/router/src/lib.rs
+++ b/router/src/lib.rs
@@ -64,39 +64,16 @@ impl HubTokenizerConfig {
     }
 }
 
-mod json_object_or_string_to_string {
-    use serde::{Deserialize, Deserializer};
-    use serde_json::Value;
-
-    // A custom deserializer that treats both strings and objects as strings.
-    // This provides flexibility with input formats for the 'grammar' field.
-    pub fn deserialize<'de, D>(deserializer: D) -> Result<String, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        let value = Value::deserialize(deserializer)?;
-
-        match value {
-            Value::String(s) => Ok(s),
-            // Safely handle serialization and return an error if it fails
-            Value::Object(o) => {
-                serde_json::to_string(&o).map_err(|e| serde::de::Error::custom(e.to_string()))
-            }
-            _ => Err(serde::de::Error::custom(
-                "expected string or object for grammar",
-            )),
-        }
-    }
-}
-
 #[derive(Clone, Debug, Deserialize, ToSchema)]
 #[serde(tag = "type", content = "value")]
 pub(crate) enum GrammarType {
-    #[serde(
-        rename = "json",
-        deserialize_with = "json_object_or_string_to_string::deserialize"
-    )]
-    Json(String),
+    /// A string that represents a [JSON Schema](https://json-schema.org/).
+    ///
+    /// JSON Schema is a declarative language that allows to annotate JSON documents
+    /// with types and descriptions.
+    #[serde(rename = "json")]
+    #[schema(example = json ! ({"properties": {"location":{"type": "string"}}}))]
+    Json(serde_json::Value),
     #[serde(rename = "regex")]
     Regex(String),
 }
diff --git a/router/src/server.rs b/router/src/server.rs
index 054ba5a2..ebde7133 100644
--- a/router/src/server.rs
+++ b/router/src/server.rs
@@ -893,6 +893,7 @@ pub async fn run(
     Info,
     CompatGenerateRequest,
     GenerateRequest,
+    GrammarType,
     ChatRequest,
     Message,
     ChatCompletionChoice,
diff --git a/router/src/validation.rs b/router/src/validation.rs
index bf85b12f..204dbf92 100644
--- a/router/src/validation.rs
+++ b/router/src/validation.rs
@@ -1,7 +1,9 @@
 /// Payload validation logic
 use crate::validation::ValidationError::{BestOfSampling, BestOfSeed, EmptyInput};
 use crate::{GenerateParameters, GenerateRequest, GrammarType};
+use jsonschema::{Draft, JSONSchema};
 use rand::{thread_rng, Rng};
+use serde_json::Value;
 use text_generation_client::{
     GrammarType as ProtoGrammarType, NextTokenChooserParameters, StoppingCriteriaParameters,
 };
@@ -313,8 +315,29 @@ impl Validation {
                     return Err(ValidationError::Grammar);
                 }
                 match grammar {
-                    // currently both are handled the same way since compilation is done in Python
-                    GrammarType::Json(json) => (json, ProtoGrammarType::Json.into()),
+                    GrammarType::Json(json) => {
+                        let json = match json {
+                            // if value is a string, we need to parse it again to make sure its
+                            // a valid json
+                            Value::String(s) => serde_json::from_str(&s)
+                                .map_err(|e| ValidationError::InvalidGrammar(e.to_string())),
+                            Value::Object(_) => Ok(json),
+                            _ => Err(ValidationError::Grammar),
+                        }?;
+
+                        // Check if the json is a valid JSONSchema
+                        JSONSchema::options()
+                            .with_draft(Draft::Draft202012)
+                            .compile(&json)
+                            .map_err(|e| ValidationError::InvalidGrammar(e.to_string()))?;
+
+                        (
+                            // Serialize json to string
+                            serde_json::to_string(&json)
+                                .map_err(|e| ValidationError::InvalidGrammar(e.to_string()))?,
+                            ProtoGrammarType::Json.into(),
+                        )
+                    }
                     GrammarType::Regex(regex) => (regex, ProtoGrammarType::Regex.into()),
                 }
             }
@@ -486,6 +509,8 @@ pub enum ValidationError {
     Tokenizer(String),
     #[error("grammar is not supported")]
     Grammar,
+    #[error("grammar is not valid: {0}")]
+    InvalidGrammar(String),
 }
 
 #[cfg(test)]
diff --git a/server/text_generation_server/utils/tokens.py b/server/text_generation_server/utils/tokens.py
index 72c6c21c..32789850 100644
--- a/server/text_generation_server/utils/tokens.py
+++ b/server/text_generation_server/utils/tokens.py
@@ -328,7 +328,6 @@ class HeterogeneousNextTokenChooser:
             scores = scores.view(B, S, -1)
 
         next_ids = torch.zeros((B, S), device=scores.device, dtype=torch.long)
-        mask = torch.full((scores.shape[-1],), -math.inf, device=self.device)
 
         for j in range(S):
             _scores = scores[:, j]
@@ -338,10 +337,10 @@ class HeterogeneousNextTokenChooser:
                 _scores = self.repetition_processor(input_ids, _scores)
             if self.frequency_processor is not None:
                 _scores = self.frequency_processor(input_ids, _scores)
-            for warper in self.warpers:
-                _scores = warper(input_ids, _scores)
             if self.grammar_processor is not None:
                 _scores = self.grammar_processor(_scores, self.fsm_grammar_states)
+            for warper in self.warpers:
+                _scores = warper(input_ids, _scores)
             _next_ids = self.choice(_scores)
             scores[:, j] = _scores
             next_ids[:, j] = _next_ids