diff --git a/crates/generator/Cargo.lock b/crates/generator/Cargo.lock
new file mode 100644
index 0000000..daf21d8
--- /dev/null
+++ b/crates/generator/Cargo.lock
@@ -0,0 +1,290 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "autocfg"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c4b4d0bd25bd0b74681c0ad21497610ce1b7c91b1022cd21c80c6fbdd9476b0"
+
+[[package]]
+name = "block-buffer"
+version = "0.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+dependencies = [
+ "generic-array",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53fe5e26ff1b7aef8bca9c6080520cfb8d9333c7568e1829cef191a9723e5504"
+dependencies = [
+ "libc",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88a41f105fe1d5b6b34b2055e3dc59bb79b46b48b2040b9e6c7b4b5de097aa41"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "generator"
+version = "0.1.0"
+dependencies = [
+ "fs-err",
+ "handlebars",
+]
+
+[[package]]
+name = "generic-array"
+version = "0.14.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
+[[package]]
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+checksum = "d08485b96a0e6393e9e4d1b8d48cf74ad6c063cd905eb33f42c1ce3f0377539b"
+dependencies = [
+ "log",
+ "pest",
+ "pest_derive",
+ "serde",
+ "serde_json",
+ "thiserror",
+]
+
+[[package]]
+name = "itoa"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
+
+[[package]]
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+[[package]]
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+
+[[package]]
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+
+[[package]]
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+
+[[package]]
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+dependencies = [
+ "memchr",
+ "thiserror",
+ "ucd-trie",
+]
+
+[[package]]
+name = "pest_derive"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "26293c9193fbca7b1a3bf9b79dc1e388e927e6cacaa78b4a3ab705a1d3d41459"
+dependencies = [
+ "pest",
+ "pest_generator",
+]
+
+[[package]]
+name = "pest_generator"
+version = "2.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ec22af7d3fb470a85dd2ca96b7c577a1eb4ef6f1683a9fe9a8c16e136c04687"
+dependencies = [
+ "pest",
+ "pest_meta",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "pest_meta"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7a240022f37c361ec1878d646fc5b7d7c4d28d5946e1a80ad5a7a4f4ca0bdcd"
+dependencies = [
+ "once_cell",
+ "pest",
+ "sha2",
+]
+
+[[package]]
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+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
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+checksum = "0fa76aaf39101c457836aec0ce2316dbdc3ab723cdda1c6bd4e6ad4208acaca7"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
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+
+[[package]]
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+checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
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+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
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+checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "455182ea6142b14f93f4bc5320a2b31c1f266b66a4a5c858b013302a5d8cbfc3"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "sha2"
+version = "0.10.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "793db75ad2bcafc3ffa7c68b215fee268f537982cd901d132f89c6343f3a3dc8"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c42f3f41a2de00b01c0aaad383c5a45241efc8b2d1eda5661812fda5f3cdcff5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "typenum"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed646292ffc8188ef8ea4d1e0e0150fb15a5c2e12ad9b8fc191ae7a8a7f3c4b9"
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
+
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
diff --git a/crates/generator/Cargo.toml b/crates/generator/Cargo.toml
new file mode 100644
index 0000000..cbc68e1
--- /dev/null
+++ b/crates/generator/Cargo.toml
@@ -0,0 +1,11 @@
+[workspace]
+
+[package]
+name = "generator"
+publish = false
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+fs-err = "2.11.0"
+handlebars = "5.1.2"
diff --git a/crates/generator/src/main.rs b/crates/generator/src/main.rs
new file mode 100644
index 0000000..6f0c3ca
--- /dev/null
+++ b/crates/generator/src/main.rs
@@ -0,0 +1,41 @@
+use std::{collections::BTreeMap, env, path::Path};
+
+use handlebars::Handlebars;
+
+fn main() {
+    let versions: Vec<i64> = env::args()
+        .skip(1) // skip the binary's own name, only keep explicit args
+        .map(|value| {
+            value
+                .parse()
+                .unwrap_or_else(|e| panic!("invalid version \"{value}\": {e}"))
+        })
+        .collect();
+    let mut handlebars = Handlebars::new();
+    let mut args = BTreeMap::new();
+    args.insert("version_numbers", versions.as_slice());
+
+    let template_and_output = [
+        ("../../template/parser.template.rs", "../../src/parser.rs"),
+        ("../../template/query.template.rs", "../../src/query.rs"),
+        (
+            "../../template/versioned.template.rs",
+            "../../src/versioned.rs",
+        ),
+    ];
+    for (template_file, target) in template_and_output {
+        let output = materialize(&mut handlebars, Path::new(template_file), &args);
+        fs_err::write(Path::new(target), output).expect("failed to write file");
+    }
+}
+
+fn materialize(
+    handlebars: &mut Handlebars,
+    template_file: &Path,
+    args: &BTreeMap<&str, &[i64]>,
+) -> String {
+    let template = fs_err::read_to_string(template_file).expect("failed to read file");
+    handlebars
+        .render_template(&template, args)
+        .expect("failed to render template")
+}
diff --git a/scripts/add_next_rustdoc_version.sh b/scripts/add_next_rustdoc_version.sh
new file mode 100644
index 0000000..8b943d5
--- /dev/null
+++ b/scripts/add_next_rustdoc_version.sh
@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+
+# Script requirements:
+# - python
+# - yq
+
+# Fail on first error, on undefined variables, and on failures in pipelines.
+set -euo pipefail
+
+# Go to the repo root directory.
+cd "$(git rev-parse --show-toplevel)"
+
+CURRENT_VERSIONS="$(yq '.features.default' Cargo.toml -o json | \
+    python -m json.tool --compact | \
+    sed 's/,/, /g' | \
+    sed 's/\[//g' | \
+    sed 's/]//g')"
+NEXT_VERSION_NUMBER="$(yq '.features.default.[-1] | sub("v(\d+)", "${1}") | to_number | (. + 1)' Cargo.toml -o json -r)"
+
+ALL_VERSIONS="$(yq '.features.default[] | sub("v(\d+)", "${1}")' Cargo.toml -o json -r) ${NEXT_VERSION_NUMBER}"
+
+# Generate the new Rust source for the specified versions.
+pushd crates/generator
+cargo run -- $ALL_VERSIONS
+popd
+
+# Reformat the generated Rust source code.
+cargo fmt
+
+# Update the Cargo.toml file to add the new dependency and feature number.
+
+# '1h;2,$H;$!d;g' means "look two lines at a time":
+# https://unix.stackexchange.com/questions/26284/how-can-i-use-sed-to-replace-a-multi-line-string
+sed -e '1h;2,$H;$!d;g' \
+    -e "s/\n\[features\]/trustfall-rustdoc-adapter-v${NEXT_VERSION_NUMBER} = { package = \"trustfall-rustdoc-adapter\", version = \">=${NEXT_VERSION_NUMBER}.0.0,<${NEXT_VERSION_NUMBER}.1.0\", optional = true }\n\n[features]/" \
+    -i Cargo.toml
+
+DEFAULT_MATCHER="default = \[${CURRENT_VERSIONS}\]"
+sed -e "s/$DEFAULT_MATCHER/default = [${CURRENT_VERSIONS}, \"v${NEXT_VERSION_NUMBER}\"]/" \
+    -i Cargo.toml
+
+echo "v${NEXT_VERSION_NUMBER} = [\"dep:trustfall-rustdoc-adapter-v${NEXT_VERSION_NUMBER}\"]" >>Cargo.toml
+
+# Ensure cargo regenerates the lockfile.
+cargo check
diff --git a/template/parser.template.rs b/template/parser.template.rs
new file mode 100644
index 0000000..ea1cf17
--- /dev/null
+++ b/template/parser.template.rs
@@ -0,0 +1,60 @@
+use std::path::Path;
+use std::{fs::File, io::Read};
+
+use anyhow::{bail, Context};
+use serde::Deserialize;
+
+use crate::versioned::VersionedCrate;
+
+#[derive(Deserialize)]
+struct RustdocFormatVersion {
+    format_version: u32,
+}
+
+fn detect_rustdoc_format_version(path: &Path, file_data: &str) -> anyhow::Result<u32> {
+    let version = serde_json::from_str::<RustdocFormatVersion>(file_data)
+        .with_context(|| format!("unrecognized rustdoc format for file {}", path.display()))?;
+
+    Ok(version.format_version)
+}
+
+fn parse_or_report_error<T>(path: &Path, file_data: &str, format_version: u32) -> anyhow::Result<T>
+where
+    T: for<'a> Deserialize<'a>,
+{
+    serde_json::from_str(file_data).with_context(|| {
+        format!(
+            "unexpected parse error for v{format_version} rustdoc for file {}",
+            path.display()
+        )
+    })
+}
+
+pub fn load_rustdoc(path: &Path) -> anyhow::Result<VersionedCrate> {
+    // Parsing JSON after fully reading a file into memory is much faster than
+    // parsing directly from a file, even if buffered:
+    // https://github.com/serde-rs/json/issues/160
+    let mut file_data = String::new();
+    File::open(path)
+        .with_context(|| format!("failed to open rustdoc JSON file {}", path.display()))?
+        .read_to_string(&mut file_data)
+        .with_context(|| format!("failed to read rustdoc JSON file {}", path.display()))?;
+
+    let format_version = detect_rustdoc_format_version(path, &file_data)?;
+
+    match format_version {
+        {{#each version_numbers}}
+        #[cfg(feature = "v{{this}}")]
+        {{this}} => Ok(VersionedCrate::V{{this}}(parse_or_report_error(
+            path,
+            &file_data,
+            format_version,
+        )?)),
+
+        {{/each}}
+        _ => bail!(
+            "rustdoc format v{format_version} for file {} is not supported",
+            path.display()
+        ),
+    }
+}
diff --git a/template/query.template.rs b/template/query.template.rs
new file mode 100644
index 0000000..69ba71e
--- /dev/null
+++ b/template/query.template.rs
@@ -0,0 +1,25 @@
+use std::{collections::BTreeMap, sync::Arc};
+
+use trustfall::{execute_query, FieldValue};
+
+use crate::versioned::VersionedRustdocAdapter;
+
+type QueryResult = BTreeMap<Arc<str>, FieldValue>;
+
+impl<'a> VersionedRustdocAdapter<'a> {
+    pub fn run_query<K: Into<Arc<str>>, V: Into<FieldValue>>(
+        &self,
+        query: &str,
+        vars: BTreeMap<K, V>,
+    ) -> anyhow::Result<Box<dyn Iterator<Item = QueryResult> + 'a>> {
+        match self {
+            {{#each version_numbers}}
+            #[cfg(feature = "v{{this}}")]
+            VersionedRustdocAdapter::V{{this}}(_, adapter) => {
+                execute_query(self.schema(), adapter.clone(), query, vars)
+            }
+
+            {{/each}}
+        }
+    }
+}
diff --git a/template/versioned.template.rs b/template/versioned.template.rs
new file mode 100644
index 0000000..1b3151e
--- /dev/null
+++ b/template/versioned.template.rs
@@ -0,0 +1,132 @@
+use std::{fmt::Debug, sync::Arc};
+
+use anyhow::bail;
+use trustfall::Schema;
+
+macro_rules! add_version_method {
+    () => {
+        pub fn version(&self) -> u32 {
+            match self {
+                {{#each version_numbers}}
+                #[cfg(feature = "v{{this}}")]
+                Self::V{{this}}(..) => {{this}},
+
+                {{/each}}
+            }
+        }
+    };
+}
+
+#[non_exhaustive]
+#[derive(Debug)]
+pub enum VersionedCrate {
+    {{#each version_numbers}}
+    #[cfg(feature = "v{{this}}")]
+    V{{this}}(trustfall_rustdoc_adapter_v{{this}}::Crate),
+
+    {{/each}}
+}
+
+#[non_exhaustive]
+#[derive(Debug)]
+pub enum VersionedIndexedCrate<'a> {
+    {{#each version_numbers}}
+    #[cfg(feature = "v{{this}}")]
+    V{{this}}(trustfall_rustdoc_adapter_v{{this}}::IndexedCrate<'a>),
+
+    {{/each}}
+}
+
+#[non_exhaustive]
+pub enum VersionedRustdocAdapter<'a> {
+    {{#each version_numbers}}
+    #[cfg(feature = "v{{this}}")]
+    V{{this}}(
+        Schema,
+        Arc<trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter<'a>>,
+    ),
+
+    {{/each}}
+}
+
+impl VersionedCrate {
+    pub fn crate_version(&self) -> Option<&str> {
+        match self {
+            {{#each version_numbers}}
+            #[cfg(feature = "v{{this}}")]
+            VersionedCrate::V{{this}}(c) => c.crate_version.as_deref(),
+
+            {{/each}}
+        }
+    }
+
+    add_version_method!();
+}
+
+impl<'a> VersionedIndexedCrate<'a> {
+    pub fn new(crate_: &'a VersionedCrate) -> Self {
+        match &crate_ {
+            {{#each version_numbers}}
+            #[cfg(feature = "v{{this}}")]
+            VersionedCrate::V{{this}}(c) => {
+                Self::V{{this}}(trustfall_rustdoc_adapter_v{{this}}::IndexedCrate::new(c))
+            }
+
+            {{/each}}
+        }
+    }
+
+    add_version_method!();
+}
+
+impl<'a> VersionedRustdocAdapter<'a> {
+    pub fn new(
+        current: &'a VersionedIndexedCrate,
+        baseline: Option<&'a VersionedIndexedCrate>,
+    ) -> anyhow::Result<Self> {
+        match (current, baseline) {
+            {{#each version_numbers}}
+            #[cfg(feature = "v{{this}}")]
+            (VersionedIndexedCrate::V{{this}}(c), Some(VersionedIndexedCrate::V{{this}}(b))) => {
+                let adapter = Arc::new(trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::new(
+                    c,
+                    Some(b),
+                ));
+                Ok(VersionedRustdocAdapter::V{{this}}(
+                    trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::schema(),
+                    adapter,
+                ))
+            }
+
+            #[cfg(feature = "v{{this}}")]
+            (VersionedIndexedCrate::V{{this}}(c), None) => {
+                let adapter = Arc::new(trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::new(c, None));
+                Ok(VersionedRustdocAdapter::V{{this}}(
+                    trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::schema(),
+                    adapter,
+                ))
+            }
+
+            {{/each}}
+            (c, Some(b)) => {
+                bail!(
+                    "version mismatch between current (v{}) and baseline (v{}) format versions",
+                    c.version(),
+                    b.version()
+                )
+            }
+        }
+    }
+
+    pub fn schema(&self) -> &Schema {
+        match self {
+            {{#each version_numbers}}
+            #[cfg(feature = "v{{this}}")]
+            VersionedRustdocAdapter::V{{this}}(schema, ..) => schema,
+
+            {{/each}}
+        }
+    }
+
+    add_version_method!();
+}