diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6745667c..090aaad9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -278,11 +278,34 @@ jobs:
           flags: python
           token: ${{ secrets.CODECOV_TOKEN }}
 
+  # Ensure that serialized extensions match rust implementation
+  tket2-extensions:
+    needs: [changes, tests-rs-stable-all-features]
+    if: ${{ needs.changes.outputs.rust == 'true' && github.event_name != 'merge_group' }}
+    name: Check standard extensions
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: mozilla-actions/sccache-action@v0.0.5
+      - name: Install stable toolchain
+        uses: dtolnay/rust-toolchain@stable
+      - uses: extractions/setup-just@v2
+      - name: Generate the updated definitions
+        run: just gen-extensions
+      - name: Check if the declarations are up to date
+        run: |
+          git diff --exit-code --name-only tket2-py/tket2/extensions/_json_defs
+          if [ $? -ne 0 ]; then
+            echo "The serialized standard extensions are not up to date"
+            echo "Please run 'just gen-extensions' and commit the changes"
+            exit 1
+          fi
+
   # This is a meta job to mark successful completion of the required checks,
   # even if they are skipped due to no changes in the relevant files.
   required-checks:
     name: Required checks 🦀+🐍
-    needs: [changes, check-rs, check-py, tests-rs-stable-no-features, tests-rs-stable-all-features, tests-py]
+    needs: [changes, check-rs, check-py, tests-rs-stable-no-features, tests-rs-stable-all-features, tests-py, tket2-extensions]
     if: ${{ !cancelled() }}
     runs-on: ubuntu-latest
     steps:
diff --git a/Cargo.lock b/Cargo.lock
index 79cc6812..79fcca75 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -261,6 +261,16 @@ dependencies = [
  "clap_derive",
 ]
 
+[[package]]
+name = "clap-verbosity-flag"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63d19864d6b68464c59f7162c9914a0b569ddc2926b4a2d71afe62a9738eff53"
+dependencies = [
+ "clap",
+ "log",
+]
+
 [[package]]
 name = "clap_builder"
 version = "4.5.17"
@@ -291,6 +301,21 @@ version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4b82cf0babdbd58558212896d1a4272303a57bdb245c2bf1147185fb45640e70"
 
+[[package]]
+name = "clio"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7fc6734af48458f72f5a3fa7b840903606427d98a710256e808f76a965047d9"
+dependencies = [
+ "cfg-if",
+ "clap",
+ "is-terminal",
+ "libc",
+ "tempfile",
+ "walkdir",
+ "windows-sys 0.42.0",
+]
+
 [[package]]
 name = "colorchoice"
 version = "1.0.1"
@@ -567,6 +592,22 @@ dependencies = [
  "typeid",
 ]
 
+[[package]]
+name = "errno"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "534c5cf6194dfab3db3242765c03bbe257cf92f22b38f6bc0c58d59108a820ba"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "fastrand"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8c02a5121d4ea3eb16a80748c74f5549a5665e4c21333c6098f283870fbdea6"
+
 [[package]]
 name = "fixedbitset"
 version = "0.4.2"
@@ -760,6 +801,21 @@ dependencies = [
  "hugr-passes",
 ]
 
+[[package]]
+name = "hugr-cli"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6df2f78a68df30280cc351522dee4d537707478d216758aa7404cbeb13aa770"
+dependencies = [
+ "clap",
+ "clap-verbosity-flag",
+ "clio",
+ "hugr-core",
+ "serde",
+ "serde_json",
+ "thiserror",
+]
+
 [[package]]
 name = "hugr-core"
 version = "0.9.1"
@@ -955,9 +1011,15 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
-version = "0.2.155"
+version = "0.2.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"
+checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
+
+[[package]]
+name = "linux-raw-sys"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78b3ae25bc7c8c38cec158d1f2757ee79e9b3740fbc7ccf0e59e4b08d793fa89"
 
 [[package]]
 name = "lock_api"
@@ -1516,6 +1578,19 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.38.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f55e80d50763938498dd5ebb18647174e0c76dc38c5505294bb224624f30f36"
+dependencies = [
+ "bitflags",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.17"
@@ -1682,6 +1757,19 @@ version = "0.12.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4873307b7c257eddcb50c9bedf158eb669578359fb28428bef438fec8e6ba7c2"
 
+[[package]]
+name = "tempfile"
+version = "3.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04cbcdd0c794ebb0d4cf35e88edd2f7d2c4c3e9a5a6dab322839b321c6a87a64"
+dependencies = [
+ "cfg-if",
+ "fastrand",
+ "once_cell",
+ "rustix",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "thiserror"
 version = "1.0.63"
@@ -1848,8 +1936,10 @@ dependencies = [
 name = "tket2-hseries"
 version = "0.2.0"
 dependencies = [
+ "clap",
  "cool_asserts",
  "hugr",
+ "hugr-cli",
  "itertools 0.13.0",
  "lazy_static",
  "petgraph",
@@ -2191,6 +2281,21 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a3e1820f08b8513f676f7ab6c1f99ff312fb97b553d30ff4dd86f9f15728aa7"
+dependencies = [
+ "windows_aarch64_gnullvm 0.42.2",
+ "windows_aarch64_msvc 0.42.2",
+ "windows_i686_gnu 0.42.2",
+ "windows_i686_msvc 0.42.2",
+ "windows_x86_64_gnu 0.42.2",
+ "windows_x86_64_gnullvm 0.42.2",
+ "windows_x86_64_msvc 0.42.2",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.45.0"
@@ -2209,6 +2314,15 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.59.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.42.2"
diff --git a/Cargo.toml b/Cargo.toml
index 7d503b6a..7da38922 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,7 @@ missing_docs = "warn"
 # Make sure to run `just recompile-eccs` if the hugr serialisation format changes.
 hugr = "0.12.1"
 hugr-core = "0.9.1"
+hugr-cli = "0.6.0"
 portgraph = "0.12"
 pyo3 = "0.21.2"
 itertools = "0.13.0"
diff --git a/justfile b/justfile
index 0ab0d9c3..7e33e32f 100644
--- a/justfile
+++ b/justfile
@@ -44,6 +44,9 @@ coverage language="[rust|python]": (_run_lang language \
 recompile-eccs:
     scripts/compile-test-eccs.sh
 
+# Generate serialized declarations for the tket2 extensions
+gen-extensions:
+    cargo run -p tket2-hseries gen-extensions -o tket2-py/tket2/extensions/_json_defs
 
 # Runs a rust and a python command, depending on the `language` variable.
 #
diff --git a/tket2-hseries/Cargo.toml b/tket2-hseries/Cargo.toml
index 5534a985..04568cf2 100644
--- a/tket2-hseries/Cargo.toml
+++ b/tket2-hseries/Cargo.toml
@@ -13,6 +13,14 @@ description = "TKET2 tool for preparing and validating `Hugr`s for compilation t
 keywords = ["Quantum", "Quantinuum"]
 categories = ["compilers"]
 
+[features]
+default = ["cli"]
+cli = ["dep:clap", "dep:hugr-cli"]
+
+[[bin]]
+name = "tket2-hseries"
+required-features = ["cli"]
+
 [dependencies]
 hugr.workspace = true
 tket2 = { path = "../tket2", version = "0.2.0" }
@@ -24,6 +32,8 @@ strum.workspace = true
 strum_macros.workspace = true
 thiserror.workspace = true
 itertools.workspace = true
+clap = { workspace = true, optional = true}
+hugr-cli = { workspace = true, optional = true }
 
 [dev-dependencies]
 cool_asserts.workspace = true
diff --git a/tket2-hseries/src/bin/tket2-hseries.rs b/tket2-hseries/src/bin/tket2-hseries.rs
new file mode 100644
index 00000000..a610603c
--- /dev/null
+++ b/tket2-hseries/src/bin/tket2-hseries.rs
@@ -0,0 +1,26 @@
+//! CLI for tket2-hseries
+
+use clap::Parser as _;
+use hugr::extension::ExtensionRegistry;
+use tket2_hseries::cli::CliArgs;
+
+fn main() {
+    match CliArgs::parse() {
+        CliArgs::GenExtensions(args) => {
+            let reg = ExtensionRegistry::try_new([
+                tket2::extension::TKET2_EXTENSION.to_owned(),
+                tket2::extension::angle::ANGLE_EXTENSION.to_owned(),
+                tket2_hseries::extension::hseries::EXTENSION.to_owned(),
+                tket2_hseries::extension::futures::EXTENSION.to_owned(),
+                tket2_hseries::extension::result::EXTENSION.to_owned(),
+            ])
+            .unwrap();
+
+            args.run_dump(&reg);
+        }
+        _ => {
+            eprintln!("Unknown command");
+            std::process::exit(1);
+        }
+    };
+}
diff --git a/tket2-hseries/src/cli.rs b/tket2-hseries/src/cli.rs
new file mode 100644
index 00000000..2bbb41af
--- /dev/null
+++ b/tket2-hseries/src/cli.rs
@@ -0,0 +1,14 @@
+//! CLI tools for tket2-hseries.
+
+use clap::Parser;
+
+/// CLI arguments.
+#[derive(Parser, Debug)]
+#[clap(version = "1.0", long_about = None)]
+#[clap(about = "tket2-hseries CLI tools.")]
+#[group(id = "tket2-hseries")]
+#[non_exhaustive]
+pub enum CliArgs {
+    /// Generate serialized extensions.
+    GenExtensions(hugr_cli::extensions::ExtArgs),
+}
diff --git a/tket2-hseries/src/lib.rs b/tket2-hseries/src/lib.rs
index f53fb643..777b7c28 100644
--- a/tket2-hseries/src/lib.rs
+++ b/tket2-hseries/src/lib.rs
@@ -15,6 +15,8 @@ use thiserror::Error;
 use extension::{futures::FutureOpDef, hseries::HSeriesOp};
 use lazify_measure::{LazifyMeasurePass, LazifyMeasurePassError};
 
+#[cfg(feature = "cli")]
+pub mod cli;
 pub mod extension;
 
 pub mod lazify_measure;
diff --git a/tket2-py/tket2/extensions/_json_defs/tket2/angle.json b/tket2-py/tket2/extensions/_json_defs/tket2/angle.json
new file mode 100644
index 00000000..fba13689
--- /dev/null
+++ b/tket2-py/tket2/extensions/_json_defs/tket2/angle.json
@@ -0,0 +1,396 @@
+{
+  "version": "0.1.0",
+  "name": "tket2.angle",
+  "extension_reqs": [],
+  "types": {
+    "angle": {
+      "extension": "tket2.angle",
+      "name": "angle",
+      "params": [],
+      "description": "angle type expressed as dyadic rational multiples of 2π",
+      "bound": {
+        "b": "Explicit",
+        "bound": "C"
+      }
+    }
+  },
+  "values": {},
+  "operations": {
+    "aadd": {
+      "extension": "tket2.angle",
+      "name": "aadd",
+      "description": "addition of angles",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "adiv": {
+      "extension": "tket2.angle",
+      "name": "adiv",
+      "description": "Divide angle by an integer. If the integer is not a power of 2, or if the resulting denominator would exceed 2^64, the result is rounded to the nearest multiple of 2 pi / 2^ 64",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "I"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "aeq": {
+      "extension": "tket2.angle",
+      "name": "aeq",
+      "description": "check angle equality",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Sum",
+              "s": "Unit",
+              "size": 2
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "afromrad": {
+      "extension": "tket2.angle",
+      "name": "afromrad",
+      "description": "construct angle from radians, rounding given a log-denominator",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "I"
+            },
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "amul": {
+      "extension": "tket2.angle",
+      "name": "amul",
+      "description": "multiply angle by a scalar",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "I"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "aneg": {
+      "extension": "tket2.angle",
+      "name": "aneg",
+      "description": "negation of an angle",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "anew": {
+      "extension": "tket2.angle",
+      "name": "anew",
+      "description": "construct angle from numerator and log-denominator, returning an error if invalid",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "I"
+            },
+            {
+              "t": "I"
+            }
+          ],
+          "output": [
+            {
+              "t": "Sum",
+              "s": "General",
+              "rows": [
+                [
+                  {
+                    "t": "Opaque",
+                    "extension": "prelude",
+                    "id": "error",
+                    "args": [],
+                    "bound": "C"
+                  }
+                ],
+                [
+                  {
+                    "t": "Opaque",
+                    "extension": "tket2.angle",
+                    "id": "angle",
+                    "args": [],
+                    "bound": "C"
+                  }
+                ]
+              ]
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "aparts": {
+      "extension": "tket2.angle",
+      "name": "aparts",
+      "description": "decompose angle into numerator and log-denominator",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "I"
+            },
+            {
+              "t": "I"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "asub": {
+      "extension": "tket2.angle",
+      "name": "asub",
+      "description": "subtraction of the second angle from the first",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "atorad": {
+      "extension": "tket2.angle",
+      "name": "atorad",
+      "description": "convert angle to radians",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "atrunc": {
+      "extension": "tket2.angle",
+      "name": "atrunc",
+      "description": "truncate an angle to one with a lower log-denominator with the nearest value, rounding down in [0, 2π) if necessary",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "I"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    }
+  }
+}
diff --git a/tket2-py/tket2/extensions/_json_defs/tket2/futures.json b/tket2-py/tket2/extensions/_json_defs/tket2/futures.json
new file mode 100644
index 00000000..7263042b
--- /dev/null
+++ b/tket2-py/tket2/extensions/_json_defs/tket2/futures.json
@@ -0,0 +1,172 @@
+{
+  "version": "0.1.0",
+  "name": "tket2.futures",
+  "extension_reqs": [],
+  "types": {
+    "Future": {
+      "extension": "tket2.futures",
+      "name": "Future",
+      "params": [
+        {
+          "tp": "Type",
+          "b": "A"
+        }
+      ],
+      "description": "A value that is computed asynchronously",
+      "bound": {
+        "b": "Explicit",
+        "bound": "A"
+      }
+    }
+  },
+  "values": {},
+  "operations": {
+    "Dup": {
+      "extension": "tket2.futures",
+      "name": "Dup",
+      "description": "Duplicate a Future. The original Future is consumed and two Futures are returned",
+      "signature": {
+        "params": [
+          {
+            "tp": "Type",
+            "b": "A"
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.futures",
+              "id": "Future",
+              "args": [
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "V",
+                    "i": 0,
+                    "b": "A"
+                  }
+                }
+              ],
+              "bound": "A"
+            }
+          ],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.futures",
+              "id": "Future",
+              "args": [
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "V",
+                    "i": 0,
+                    "b": "A"
+                  }
+                }
+              ],
+              "bound": "A"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.futures",
+              "id": "Future",
+              "args": [
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "V",
+                    "i": 0,
+                    "b": "A"
+                  }
+                }
+              ],
+              "bound": "A"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Free": {
+      "extension": "tket2.futures",
+      "name": "Free",
+      "description": "Consume a future without reading it.",
+      "signature": {
+        "params": [
+          {
+            "tp": "Type",
+            "b": "A"
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.futures",
+              "id": "Future",
+              "args": [
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "V",
+                    "i": 0,
+                    "b": "A"
+                  }
+                }
+              ],
+              "bound": "A"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Read": {
+      "extension": "tket2.futures",
+      "name": "Read",
+      "description": "Read a value from a Future, consuming it",
+      "signature": {
+        "params": [
+          {
+            "tp": "Type",
+            "b": "A"
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.futures",
+              "id": "Future",
+              "args": [
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "V",
+                    "i": 0,
+                    "b": "A"
+                  }
+                }
+              ],
+              "bound": "A"
+            }
+          ],
+          "output": [
+            {
+              "t": "V",
+              "i": 0,
+              "b": "A"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    }
+  }
+}
diff --git a/tket2-py/tket2/extensions/_json_defs/tket2/hseries.json b/tket2-py/tket2/extensions/_json_defs/tket2/hseries.json
new file mode 100644
index 00000000..700ddefa
--- /dev/null
+++ b/tket2-py/tket2/extensions/_json_defs/tket2/hseries.json
@@ -0,0 +1,265 @@
+{
+  "version": "0.1.0",
+  "name": "tket2.hseries",
+  "extension_reqs": [
+    "arithmetic.float.types",
+    "prelude",
+    "tket2.angle",
+    "tket2.futures"
+  ],
+  "types": {},
+  "values": {},
+  "operations": {
+    "LazyMeasure": {
+      "extension": "tket2.hseries",
+      "name": "LazyMeasure",
+      "description": "LazyMeasure",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.futures",
+              "id": "Future",
+              "args": [
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "Sum",
+                    "s": "Unit",
+                    "size": 2
+                  }
+                }
+              ],
+              "bound": "A"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Measure": {
+      "extension": "tket2.hseries",
+      "name": "Measure",
+      "description": "Measure",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Sum",
+              "s": "Unit",
+              "size": 2
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "PhasedX": {
+      "extension": "tket2.hseries",
+      "name": "PhasedX",
+      "description": "PhasedX",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            },
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "QAlloc": {
+      "extension": "tket2.hseries",
+      "name": "QAlloc",
+      "description": "QAlloc",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "QFree": {
+      "extension": "tket2.hseries",
+      "name": "QFree",
+      "description": "QFree",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Reset": {
+      "extension": "tket2.hseries",
+      "name": "Reset",
+      "description": "Reset",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Rz": {
+      "extension": "tket2.hseries",
+      "name": "Rz",
+      "description": "Rz",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "ZZMax": {
+      "extension": "tket2.hseries",
+      "name": "ZZMax",
+      "description": "ZZMax",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "ZZPhase": {
+      "extension": "tket2.hseries",
+      "name": "ZZPhase",
+      "description": "ZZPhase",
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    }
+  }
+}
diff --git a/tket2-py/tket2/extensions/_json_defs/tket2/quantum.json b/tket2-py/tket2/extensions/_json_defs/tket2/quantum.json
new file mode 100644
index 00000000..bf48f5f2
--- /dev/null
+++ b/tket2-py/tket2/extensions/_json_defs/tket2/quantum.json
@@ -0,0 +1,664 @@
+{
+  "version": "0.1.0",
+  "name": "tket2.quantum",
+  "extension_reqs": [],
+  "types": {},
+  "values": {},
+  "operations": {
+    "CRz": {
+      "extension": "tket2.quantum",
+      "name": "CRz",
+      "description": "CRz",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "CX": {
+      "extension": "tket2.quantum",
+      "name": "CX",
+      "description": "CX",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ],
+          [
+            1,
+            "X"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "CY": {
+      "extension": "tket2.quantum",
+      "name": "CY",
+      "description": "CY",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "CZ": {
+      "extension": "tket2.quantum",
+      "name": "CZ",
+      "description": "CZ",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ],
+          [
+            1,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "H": {
+      "extension": "tket2.quantum",
+      "name": "H",
+      "description": "H",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Measure": {
+      "extension": "tket2.quantum",
+      "name": "Measure",
+      "description": "Measure",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Sum",
+              "s": "Unit",
+              "size": 2
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "QAlloc": {
+      "extension": "tket2.quantum",
+      "name": "QAlloc",
+      "description": "QAlloc",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "QFree": {
+      "extension": "tket2.quantum",
+      "name": "QFree",
+      "description": "QFree",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Reset": {
+      "extension": "tket2.quantum",
+      "name": "Reset",
+      "description": "Reset",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Rx": {
+      "extension": "tket2.quantum",
+      "name": "Rx",
+      "description": "Rx",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "X"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Ry": {
+      "extension": "tket2.quantum",
+      "name": "Ry",
+      "description": "Ry",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Rz": {
+      "extension": "tket2.quantum",
+      "name": "Rz",
+      "description": "Rz",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "S": {
+      "extension": "tket2.quantum",
+      "name": "S",
+      "description": "S",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Sdg": {
+      "extension": "tket2.quantum",
+      "name": "Sdg",
+      "description": "Sdg",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "T": {
+      "extension": "tket2.quantum",
+      "name": "T",
+      "description": "T",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Tdg": {
+      "extension": "tket2.quantum",
+      "name": "Tdg",
+      "description": "Tdg",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Toffoli": {
+      "extension": "tket2.quantum",
+      "name": "Toffoli",
+      "description": "Toffoli",
+      "misc": {
+        "commutation": []
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            },
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "X": {
+      "extension": "tket2.quantum",
+      "name": "X",
+      "description": "X",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "X"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Y": {
+      "extension": "tket2.quantum",
+      "name": "Y",
+      "description": "Y",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Y"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "Z": {
+      "extension": "tket2.quantum",
+      "name": "Z",
+      "description": "Z",
+      "misc": {
+        "commutation": [
+          [
+            0,
+            "Z"
+          ]
+        ]
+      },
+      "signature": {
+        "params": [],
+        "body": {
+          "input": [
+            {
+              "t": "Q"
+            }
+          ],
+          "output": [
+            {
+              "t": "Q"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "symbolic_angle": {
+      "extension": "tket2.quantum",
+      "name": "symbolic_angle",
+      "description": "Store a sympy expression that can be evaluated to an angle.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          }
+        ],
+        "body": {
+          "input": [],
+          "output": [
+            {
+              "t": "Opaque",
+              "extension": "tket2.angle",
+              "id": "angle",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    }
+  }
+}
diff --git a/tket2-py/tket2/extensions/_json_defs/tket2/result.json b/tket2-py/tket2/extensions/_json_defs/tket2/result.json
new file mode 100644
index 00000000..85ed4bc4
--- /dev/null
+++ b/tket2-py/tket2/extensions/_json_defs/tket2/result.json
@@ -0,0 +1,360 @@
+{
+  "version": "0.1.0",
+  "name": "tket2.result",
+  "extension_reqs": [
+    "arithmetic.float.types",
+    "arithmetic.int.types"
+  ],
+  "types": {},
+  "values": {},
+  "operations": {
+    "result_array_bool": {
+      "extension": "tket2.result",
+      "name": "result_array_bool",
+      "description": "Report an array of boolean results.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": null
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "prelude",
+              "id": "array",
+              "args": [
+                {
+                  "tya": "Variable",
+                  "idx": 1,
+                  "cached_decl": {
+                    "tp": "BoundedNat",
+                    "bound": null
+                  }
+                },
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "Sum",
+                    "s": "Unit",
+                    "size": 2
+                  }
+                }
+              ],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_array_f64": {
+      "extension": "tket2.result",
+      "name": "result_array_f64",
+      "description": "Report an array of floating-point results.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": null
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "prelude",
+              "id": "array",
+              "args": [
+                {
+                  "tya": "Variable",
+                  "idx": 1,
+                  "cached_decl": {
+                    "tp": "BoundedNat",
+                    "bound": null
+                  }
+                },
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "Opaque",
+                    "extension": "arithmetic.float.types",
+                    "id": "float64",
+                    "args": [],
+                    "bound": "C"
+                  }
+                }
+              ],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_array_int": {
+      "extension": "tket2.result",
+      "name": "result_array_int",
+      "description": "Report an array of signed integer results.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": null
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": 7
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "prelude",
+              "id": "array",
+              "args": [
+                {
+                  "tya": "Variable",
+                  "idx": 1,
+                  "cached_decl": {
+                    "tp": "BoundedNat",
+                    "bound": null
+                  }
+                },
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "Opaque",
+                    "extension": "arithmetic.int.types",
+                    "id": "int",
+                    "args": [
+                      {
+                        "tya": "Variable",
+                        "idx": 2,
+                        "cached_decl": {
+                          "tp": "BoundedNat",
+                          "bound": 7
+                        }
+                      }
+                    ],
+                    "bound": "C"
+                  }
+                }
+              ],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_array_uint": {
+      "extension": "tket2.result",
+      "name": "result_array_uint",
+      "description": "Report an array of unsigned integer results.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": null
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": 7
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "prelude",
+              "id": "array",
+              "args": [
+                {
+                  "tya": "Variable",
+                  "idx": 1,
+                  "cached_decl": {
+                    "tp": "BoundedNat",
+                    "bound": null
+                  }
+                },
+                {
+                  "tya": "Type",
+                  "ty": {
+                    "t": "Opaque",
+                    "extension": "arithmetic.int.types",
+                    "id": "int",
+                    "args": [
+                      {
+                        "tya": "Variable",
+                        "idx": 2,
+                        "cached_decl": {
+                          "tp": "BoundedNat",
+                          "bound": 7
+                        }
+                      }
+                    ],
+                    "bound": "C"
+                  }
+                }
+              ],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_bool": {
+      "extension": "tket2.result",
+      "name": "result_bool",
+      "description": "Report a boolean result.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Sum",
+              "s": "Unit",
+              "size": 2
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_f64": {
+      "extension": "tket2.result",
+      "name": "result_f64",
+      "description": "Report a floating-point result.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.float.types",
+              "id": "float64",
+              "args": [],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_int": {
+      "extension": "tket2.result",
+      "name": "result_int",
+      "description": "Report a signed integer result.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": 7
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.int.types",
+              "id": "int",
+              "args": [
+                {
+                  "tya": "Variable",
+                  "idx": 1,
+                  "cached_decl": {
+                    "tp": "BoundedNat",
+                    "bound": 7
+                  }
+                }
+              ],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    },
+    "result_uint": {
+      "extension": "tket2.result",
+      "name": "result_uint",
+      "description": "Report an unsigned integer result.",
+      "signature": {
+        "params": [
+          {
+            "tp": "String"
+          },
+          {
+            "tp": "BoundedNat",
+            "bound": 7
+          }
+        ],
+        "body": {
+          "input": [
+            {
+              "t": "Opaque",
+              "extension": "arithmetic.int.types",
+              "id": "int",
+              "args": [
+                {
+                  "tya": "Variable",
+                  "idx": 1,
+                  "cached_decl": {
+                    "tp": "BoundedNat",
+                    "bound": 7
+                  }
+                }
+              ],
+              "bound": "C"
+            }
+          ],
+          "output": [],
+          "extension_reqs": []
+        }
+      },
+      "binary": false
+    }
+  }
+}