diff --git a/tools/aconfig/aconfig_protos/Android.bp b/tools/aconfig/aconfig_protos/Android.bp
new file mode 100644
index 0000000..1cc4e41
--- /dev/null
+++ b/tools/aconfig/aconfig_protos/Android.bp
@@ -0,0 +1,62 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+// proto libraries for consumers of `aconfig dump --format=protobuf` output
+
+java_library {
+    name: "libaconfig_java_proto_lite",
+    host_supported: true,
+    srcs: ["protos/aconfig.proto"],
+    static_libs: ["libprotobuf-java-lite"],
+    proto: {
+        type: "lite",
+    },
+    sdk_version: "current",
+    min_sdk_version: "UpsideDownCake",
+    apex_available: [
+        "com.android.configinfrastructure",
+        "//apex_available:platform",
+    ]
+}
+
+java_library_host {
+    name: "libaconfig_java_proto_full",
+    srcs: ["protos/aconfig.proto"],
+    static_libs: ["libprotobuf-java-full"],
+    proto: {
+        type: "full",
+    },
+}
+
+python_library_host {
+    name: "libaconfig_python_proto",
+    srcs: ["protos/aconfig.proto"],
+    proto: {
+        canonical_path_from_root: false,
+    },
+}
+
+rust_protobuf {
+    name: "libaconfig_rust_proto",
+    protos: ["protos/aconfig.proto"],
+    crate_name: "aconfig_rust_proto",
+    source_stem: "aconfig_rust_proto",
+    host_supported: true,
+}
+
+rust_library {
+    name: "libaconfig_protos",
+    srcs: ["src/lib.rs"],
+    crate_name: "aconfig_protos",
+    host_supported: true,
+    lints: "none",
+    rustlibs: [
+        "libaconfig_rust_proto",
+        "libanyhow",
+        "libprotobuf",
+    ],
+    proc_macros: [
+        "libpaste",
+    ]
+}
diff --git a/tools/aconfig/aconfig_protos/Cargo.toml b/tools/aconfig/aconfig_protos/Cargo.toml
new file mode 100644
index 0000000..114cf80
--- /dev/null
+++ b/tools/aconfig/aconfig_protos/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "aconfig_protos"
+version = "0.1.0"
+edition = "2021"
+build = "build.rs"
+
+[features]
+default = ["cargo"]
+cargo = []
+
+[dependencies]
+anyhow = "1.0.69"
+paste = "1.0.11"
+protobuf = "3.2.0"
+
+[build-dependencies]
+protobuf-codegen = "3.2.0"
diff --git a/tools/aconfig/aconfig_protos/build.rs b/tools/aconfig/aconfig_protos/build.rs
new file mode 100644
index 0000000..5ef5b60
--- /dev/null
+++ b/tools/aconfig/aconfig_protos/build.rs
@@ -0,0 +1,17 @@
+use protobuf_codegen::Codegen;
+
+fn main() {
+    let proto_files = vec!["protos/aconfig.proto"];
+
+    // tell cargo to only re-run the build script if any of the proto files has changed
+    for path in &proto_files {
+        println!("cargo:rerun-if-changed={}", path);
+    }
+
+    Codegen::new()
+        .pure()
+        .include("protos")
+        .inputs(proto_files)
+        .cargo_out_dir("aconfig_proto")
+        .run_from_script();
+}
diff --git a/tools/aconfig/aconfig_protos/protos/aconfig.proto b/tools/aconfig/aconfig_protos/protos/aconfig.proto
new file mode 100644
index 0000000..ed4b24c
--- /dev/null
+++ b/tools/aconfig/aconfig_protos/protos/aconfig.proto
@@ -0,0 +1,104 @@
+// Copyright (C) 2023 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License
+
+// This is the schema definition for aconfig files. Modifications need to be
+// either backwards compatible, or include updates to all aconfig files in the
+// Android tree.
+
+syntax = "proto2";
+
+package android.aconfig;
+
+// messages used in both aconfig input and output
+
+enum flag_state {
+  ENABLED = 1;
+  DISABLED = 2;
+}
+
+enum flag_permission {
+  READ_ONLY = 1;
+  READ_WRITE = 2;
+}
+
+// aconfig input messages: flag declarations and values
+
+message flag_declaration {
+  optional string name = 1;
+  optional string namespace = 2;
+  optional string description = 3;
+  repeated string bug = 4;
+  optional bool is_fixed_read_only = 5;
+  optional bool is_exported = 6;
+  optional flag_metadata metadata = 7;
+};
+
+// Optional metadata about the flag, such as its purpose and its intended form factors.
+// Can influence the applied policies and testing strategy.
+message flag_metadata {
+  enum flag_purpose {
+    PURPOSE_UNSPECIFIED = 0;
+    PURPOSE_FEATURE = 1;
+    PURPOSE_BUGFIX = 2;
+  }
+
+  optional flag_purpose purpose = 1;
+
+  // TODO(b/315025930): Add field to designate intended target device form factor(s), such as phone, watch or other.
+}
+
+message flag_declarations {
+  optional string package = 1;
+  repeated flag_declaration flag = 2;
+  optional string container = 3;
+};
+
+message flag_value {
+  optional string package = 1;
+  optional string name = 2;
+  optional flag_state state = 3;
+  optional flag_permission permission = 4;
+};
+
+message flag_values {
+  repeated flag_value flag_value = 1;
+};
+
+// aconfig output messages: parsed and verified flag declarations and values
+
+message tracepoint {
+  // path to declaration or value file relative to $TOP
+  optional string source = 1;
+  optional flag_state state = 2;
+  optional flag_permission permission = 3;
+}
+
+message parsed_flag {
+  optional string package = 1;
+  optional string name = 2;
+  optional string namespace = 3;
+  optional string description = 4;
+  repeated string bug = 5;
+  optional flag_state state = 6;
+  optional flag_permission permission = 7;
+  repeated tracepoint trace = 8;
+  optional bool is_fixed_read_only = 9;
+  optional bool is_exported = 10;
+  optional string container = 11;
+  optional flag_metadata metadata = 12;
+}
+
+message parsed_flags {
+  repeated parsed_flag parsed_flag = 1;
+}
diff --git a/tools/aconfig/aconfig_protos/src/lib.rs b/tools/aconfig/aconfig_protos/src/lib.rs
new file mode 100644
index 0000000..f0d27d6
--- /dev/null
+++ b/tools/aconfig/aconfig_protos/src/lib.rs
@@ -0,0 +1,1011 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// When building with the Android tool-chain
+//
+//   - an external crate `aconfig_protos` will be generated
+//   - the feature "cargo" will be disabled
+//
+// When building with cargo
+//
+//   - a local sub-module will be generated in OUT_DIR and included in this file
+//   - the feature "cargo" will be enabled
+//
+// This module hides these differences from the rest of aconfig.
+
+// ---- When building with the Android tool-chain ----
+#[cfg(not(feature = "cargo"))]
+mod auto_generated {
+    pub use aconfig_rust_proto::aconfig::flag_metadata::Flag_purpose as ProtoFlagPurpose;
+    pub use aconfig_rust_proto::aconfig::Flag_declaration as ProtoFlagDeclaration;
+    pub use aconfig_rust_proto::aconfig::Flag_declarations as ProtoFlagDeclarations;
+    pub use aconfig_rust_proto::aconfig::Flag_metadata as ProtoFlagMetadata;
+    pub use aconfig_rust_proto::aconfig::Flag_permission as ProtoFlagPermission;
+    pub use aconfig_rust_proto::aconfig::Flag_state as ProtoFlagState;
+    pub use aconfig_rust_proto::aconfig::Flag_value as ProtoFlagValue;
+    pub use aconfig_rust_proto::aconfig::Flag_values as ProtoFlagValues;
+    pub use aconfig_rust_proto::aconfig::Parsed_flag as ProtoParsedFlag;
+    pub use aconfig_rust_proto::aconfig::Parsed_flags as ProtoParsedFlags;
+    pub use aconfig_rust_proto::aconfig::Tracepoint as ProtoTracepoint;
+}
+
+// ---- When building with cargo ----
+#[cfg(feature = "cargo")]
+mod auto_generated {
+    // include! statements should be avoided (because they import file contents verbatim), but
+    // because this is only used during local development, and only if using cargo instead of the
+    // Android tool-chain, we allow it
+    include!(concat!(env!("OUT_DIR"), "/aconfig_proto/mod.rs"));
+    pub use aconfig::flag_metadata::Flag_purpose as ProtoFlagPurpose;
+    pub use aconfig::Flag_declaration as ProtoFlagDeclaration;
+    pub use aconfig::Flag_declarations as ProtoFlagDeclarations;
+    pub use aconfig::Flag_metadata as ProtoFlagMetadata;
+    pub use aconfig::Flag_permission as ProtoFlagPermission;
+    pub use aconfig::Flag_state as ProtoFlagState;
+    pub use aconfig::Flag_value as ProtoFlagValue;
+    pub use aconfig::Flag_values as ProtoFlagValues;
+    pub use aconfig::Parsed_flag as ProtoParsedFlag;
+    pub use aconfig::Parsed_flags as ProtoParsedFlags;
+    pub use aconfig::Tracepoint as ProtoTracepoint;
+}
+
+// ---- Common for both the Android tool-chain and cargo ----
+pub use auto_generated::*;
+
+use anyhow::Result;
+use paste::paste;
+
+pub fn is_valid_name_ident(s: &str) -> bool {
+    // Identifiers must match [a-z][a-z0-9_]*, except consecutive underscores are not allowed
+    if s.contains("__") {
+        return false;
+    }
+    let mut chars = s.chars();
+    let Some(first) = chars.next() else {
+        return false;
+    };
+    if !first.is_ascii_lowercase() {
+        return false;
+    }
+    chars.all(|ch| ch.is_ascii_lowercase() || ch.is_ascii_digit() || ch == '_')
+}
+
+pub fn is_valid_package_ident(s: &str) -> bool {
+    if !s.contains('.') {
+        return false;
+    }
+    s.split('.').all(is_valid_name_ident)
+}
+
+pub fn is_valid_container_ident(s: &str) -> bool {
+    s.split('.').all(is_valid_name_ident)
+}
+
+fn try_from_text_proto<T>(s: &str) -> Result<T>
+where
+    T: protobuf::MessageFull,
+{
+    protobuf::text_format::parse_from_str(s).map_err(|e| e.into())
+}
+
+macro_rules! ensure_required_fields {
+    ($type:expr, $struct:expr, $($field:expr),+) => {
+        $(
+        paste! {
+            ensure!($struct.[<has_ $field>](), "bad {}: missing {}", $type, $field);
+        }
+        )+
+    };
+}
+
+pub mod flag_declaration {
+    use super::*;
+    use anyhow::ensure;
+
+    pub fn verify_fields(pdf: &ProtoFlagDeclaration) -> Result<()> {
+        ensure_required_fields!("flag declaration", pdf, "name", "namespace", "description");
+
+        ensure!(is_valid_name_ident(pdf.name()), "bad flag declaration: bad name");
+        ensure!(is_valid_name_ident(pdf.namespace()), "bad flag declaration: bad name");
+        ensure!(!pdf.description().is_empty(), "bad flag declaration: empty description");
+        ensure!(pdf.bug.len() == 1, "bad flag declaration: exactly one bug required");
+
+        Ok(())
+    }
+}
+
+pub mod flag_declarations {
+    use super::*;
+    use anyhow::ensure;
+
+    pub fn try_from_text_proto(s: &str) -> Result<ProtoFlagDeclarations> {
+        let pdf: ProtoFlagDeclarations = super::try_from_text_proto(s)?;
+        verify_fields(&pdf)?;
+        Ok(pdf)
+    }
+
+    pub fn verify_fields(pdf: &ProtoFlagDeclarations) -> Result<()> {
+        ensure_required_fields!("flag declarations", pdf, "package");
+        // TODO(b/312769710): Make the container field required.
+
+        ensure!(
+            is_valid_package_ident(pdf.package()),
+            "bad flag declarations: bad package"
+        );
+        ensure!(
+            !pdf.has_container() || is_valid_container_ident(pdf.container()),
+            "bad flag declarations: bad container"
+        );
+        for flag_declaration in pdf.flag.iter() {
+            super::flag_declaration::verify_fields(flag_declaration)?;
+        }
+
+        Ok(())
+    }
+}
+
+pub mod flag_value {
+    use super::*;
+    use anyhow::ensure;
+
+    pub fn verify_fields(fv: &ProtoFlagValue) -> Result<()> {
+        ensure_required_fields!("flag value", fv, "package", "name", "state", "permission");
+
+        ensure!(is_valid_package_ident(fv.package()), "bad flag value: bad package");
+        ensure!(is_valid_name_ident(fv.name()), "bad flag value: bad name");
+
+        Ok(())
+    }
+}
+
+pub mod flag_values {
+    use super::*;
+
+    pub fn try_from_text_proto(s: &str) -> Result<ProtoFlagValues> {
+        let pfv: ProtoFlagValues = super::try_from_text_proto(s)?;
+        verify_fields(&pfv)?;
+        Ok(pfv)
+    }
+
+    pub fn verify_fields(pfv: &ProtoFlagValues) -> Result<()> {
+        for flag_value in pfv.flag_value.iter() {
+            super::flag_value::verify_fields(flag_value)?;
+        }
+        Ok(())
+    }
+}
+
+pub mod flag_permission {
+    use super::*;
+    use anyhow::bail;
+
+    pub fn parse_from_str(permission: &str) -> Result<ProtoFlagPermission> {
+        match permission.to_ascii_lowercase().as_str() {
+            "read_write" => Ok(ProtoFlagPermission::READ_WRITE),
+            "read_only" => Ok(ProtoFlagPermission::READ_ONLY),
+            _ => bail!("Permission needs to be read_only or read_write."),
+        }
+    }
+
+    pub fn to_string(permission: &ProtoFlagPermission) -> &str {
+        match permission {
+            ProtoFlagPermission::READ_WRITE => "read_write",
+            ProtoFlagPermission::READ_ONLY => "read_only",
+        }
+    }
+}
+
+pub mod tracepoint {
+    use super::*;
+    use anyhow::ensure;
+
+    pub fn verify_fields(tp: &ProtoTracepoint) -> Result<()> {
+        ensure_required_fields!("tracepoint", tp, "source", "state", "permission");
+
+        ensure!(!tp.source().is_empty(), "bad tracepoint: empty source");
+
+        Ok(())
+    }
+}
+
+pub mod parsed_flag {
+    use super::*;
+    use anyhow::ensure;
+
+    pub fn verify_fields(pf: &ProtoParsedFlag) -> Result<()> {
+        ensure_required_fields!(
+            "parsed flag",
+            pf,
+            "package",
+            "name",
+            "namespace",
+            "description",
+            "state",
+            "permission"
+        );
+
+        ensure!(is_valid_package_ident(pf.package()), "bad parsed flag: bad package");
+        ensure!(
+            !pf.has_container() || is_valid_container_ident(pf.container()),
+            "bad parsed flag: bad container"
+        );
+        ensure!(is_valid_name_ident(pf.name()), "bad parsed flag: bad name");
+        ensure!(is_valid_name_ident(pf.namespace()), "bad parsed flag: bad namespace");
+        ensure!(!pf.description().is_empty(), "bad parsed flag: empty description");
+        ensure!(!pf.trace.is_empty(), "bad parsed flag: empty trace");
+        for tp in pf.trace.iter() {
+            super::tracepoint::verify_fields(tp)?;
+        }
+        ensure!(pf.bug.len() == 1, "bad flag declaration: exactly one bug required");
+        if pf.is_fixed_read_only() {
+            ensure!(
+                pf.permission() == ProtoFlagPermission::READ_ONLY,
+                "bad parsed flag: flag is is_fixed_read_only but permission is not READ_ONLY"
+            );
+            for tp in pf.trace.iter() {
+                ensure!(tp.permission() == ProtoFlagPermission::READ_ONLY,
+                "bad parsed flag: flag is is_fixed_read_only but a tracepoint's permission is not READ_ONLY"
+                );
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn path_to_declaration(pf: &ProtoParsedFlag) -> &str {
+        debug_assert!(!pf.trace.is_empty());
+        pf.trace[0].source()
+    }
+}
+
+pub mod parsed_flags {
+    use super::*;
+    use anyhow::bail;
+    use std::cmp::Ordering;
+
+    pub fn try_from_binary_proto(bytes: &[u8]) -> Result<ProtoParsedFlags> {
+        let message: ProtoParsedFlags = protobuf::Message::parse_from_bytes(bytes)?;
+        verify_fields(&message)?;
+        Ok(message)
+    }
+
+    pub fn verify_fields(pf: &ProtoParsedFlags) -> Result<()> {
+        use crate::parsed_flag::path_to_declaration;
+
+        let mut previous: Option<&ProtoParsedFlag> = None;
+        for parsed_flag in pf.parsed_flag.iter() {
+            if let Some(prev) = previous {
+                let a = create_sorting_key(prev);
+                let b = create_sorting_key(parsed_flag);
+                match a.cmp(&b) {
+                    Ordering::Less => {}
+                    Ordering::Equal => bail!(
+                        "bad parsed flags: duplicate flag {} (defined in {} and {})",
+                        a,
+                        path_to_declaration(prev),
+                        path_to_declaration(parsed_flag)
+                    ),
+                    Ordering::Greater => {
+                        bail!("bad parsed flags: not sorted: {} comes before {}", a, b)
+                    }
+                }
+            }
+            super::parsed_flag::verify_fields(parsed_flag)?;
+            previous = Some(parsed_flag);
+        }
+        Ok(())
+    }
+
+    pub fn merge(parsed_flags: Vec<ProtoParsedFlags>, dedup: bool) -> Result<ProtoParsedFlags> {
+        let mut merged = ProtoParsedFlags::new();
+        for mut pfs in parsed_flags.into_iter() {
+            merged.parsed_flag.append(&mut pfs.parsed_flag);
+        }
+        merged.parsed_flag.sort_by_cached_key(create_sorting_key);
+        if dedup {
+            // Deduplicate identical protobuf messages.  Messages with the same sorting key but
+            // different fields (including the path to the original source file) will not be
+            // deduplicated and trigger an error in verify_fields.
+            merged.parsed_flag.dedup();
+        }
+        verify_fields(&merged)?;
+        Ok(merged)
+    }
+
+    pub fn sort_parsed_flags(pf: &mut ProtoParsedFlags) {
+        pf.parsed_flag.sort_by_key(create_sorting_key);
+    }
+
+    fn create_sorting_key(pf: &ProtoParsedFlag) -> String {
+        pf.fully_qualified_name()
+    }
+}
+
+pub trait ParsedFlagExt {
+    fn fully_qualified_name(&self) -> String;
+}
+
+impl ParsedFlagExt for ProtoParsedFlag {
+    fn fully_qualified_name(&self) -> String {
+        format!("{}.{}", self.package(), self.name())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_flag_declarations_try_from_text_proto() {
+        // valid input
+        let flag_declarations = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+container: "system"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "123"
+    is_exported: true
+}
+flag {
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+    bug: "abc"
+    is_fixed_read_only: true
+}
+"#,
+        )
+        .unwrap();
+        assert_eq!(flag_declarations.package(), "com.foo.bar");
+        assert_eq!(flag_declarations.container(), "system");
+        let first = flag_declarations.flag.iter().find(|pf| pf.name() == "first").unwrap();
+        assert_eq!(first.name(), "first");
+        assert_eq!(first.namespace(), "first_ns");
+        assert_eq!(first.description(), "This is the description of the first flag.");
+        assert_eq!(first.bug, vec!["123"]);
+        assert!(!first.is_fixed_read_only());
+        assert!(first.is_exported());
+        let second = flag_declarations.flag.iter().find(|pf| pf.name() == "second").unwrap();
+        assert_eq!(second.name(), "second");
+        assert_eq!(second.namespace(), "second_ns");
+        assert_eq!(second.description(), "This is the description of the second flag.");
+        assert_eq!(second.bug, vec!["abc"]);
+        assert!(second.is_fixed_read_only());
+        assert!(!second.is_exported());
+
+        // valid input: missing container in flag declarations is supported
+        let flag_declarations = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "123"
+}
+"#,
+        )
+        .unwrap();
+        assert_eq!(flag_declarations.container(), "");
+        assert!(!flag_declarations.has_container());
+
+        // bad input: missing package in flag declarations
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+container: "system"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+}
+flag {
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+}
+"#,
+        )
+        .unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad flag declarations: missing package");
+
+        // bad input: missing namespace in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+container: "system"
+flag {
+    name: "first"
+    description: "This is the description of the first flag."
+}
+flag {
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+}
+"#,
+        )
+        .unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad flag declaration: missing namespace");
+
+        // bad input: bad package name in flag declarations
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "_com.FOO__BAR"
+container: "system"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+}
+flag {
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declarations: bad package"));
+
+        // bad input: bad name in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+container: "system"
+flag {
+    name: "FIRST"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+}
+flag {
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declaration: bad name"));
+
+        // bad input: no bug entries in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+container: "system"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declaration: exactly one bug required"));
+
+        // bad input: multiple bug entries in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+container: "system"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "123"
+    bug: "abc"
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declaration: exactly one bug required"));
+
+        // bad input: invalid container name in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+container: "__bad_bad_container.com"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "123"
+    bug: "abc"
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declarations: bad container"));
+
+        // TODO(b/312769710): Verify error when container is missing.
+    }
+
+    #[test]
+    fn test_flag_values_try_from_text_proto() {
+        // valid input
+        let flag_values = flag_values::try_from_text_proto(
+            r#"
+flag_value {
+    package: "com.first"
+    name: "first"
+    state: DISABLED
+    permission: READ_ONLY
+}
+flag_value {
+    package: "com.second"
+    name: "second"
+    state: ENABLED
+    permission: READ_WRITE
+}
+"#,
+        )
+        .unwrap();
+        let first = flag_values.flag_value.iter().find(|fv| fv.name() == "first").unwrap();
+        assert_eq!(first.package(), "com.first");
+        assert_eq!(first.name(), "first");
+        assert_eq!(first.state(), ProtoFlagState::DISABLED);
+        assert_eq!(first.permission(), ProtoFlagPermission::READ_ONLY);
+        let second = flag_values.flag_value.iter().find(|fv| fv.name() == "second").unwrap();
+        assert_eq!(second.package(), "com.second");
+        assert_eq!(second.name(), "second");
+        assert_eq!(second.state(), ProtoFlagState::ENABLED);
+        assert_eq!(second.permission(), ProtoFlagPermission::READ_WRITE);
+
+        // bad input: bad package in flag value
+        let error = flag_values::try_from_text_proto(
+            r#"
+flag_value {
+    package: "COM.FIRST"
+    name: "first"
+    state: DISABLED
+    permission: READ_ONLY
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag value: bad package"));
+
+        // bad input: bad name in flag value
+        let error = flag_values::try_from_text_proto(
+            r#"
+flag_value {
+    package: "com.first"
+    name: "FIRST"
+    state: DISABLED
+    permission: READ_ONLY
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag value: bad name"));
+
+        // bad input: missing state in flag value
+        let error = flag_values::try_from_text_proto(
+            r#"
+flag_value {
+    package: "com.first"
+    name: "first"
+    permission: READ_ONLY
+}
+"#,
+        )
+        .unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad flag value: missing state");
+
+        // bad input: missing permission in flag value
+        let error = flag_values::try_from_text_proto(
+            r#"
+flag_value {
+    package: "com.first"
+    name: "first"
+    state: DISABLED
+}
+"#,
+        )
+        .unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad flag value: missing permission");
+    }
+
+    fn try_from_binary_proto_from_text_proto(text_proto: &str) -> Result<ProtoParsedFlags> {
+        use protobuf::Message;
+
+        let parsed_flags: ProtoParsedFlags = try_from_text_proto(text_proto)?;
+        let mut binary_proto = Vec::new();
+        parsed_flags.write_to_vec(&mut binary_proto)?;
+        parsed_flags::try_from_binary_proto(&binary_proto)
+    }
+
+    #[test]
+    fn test_parsed_flags_try_from_text_proto() {
+        // valid input
+        let text_proto = r#"
+parsed_flag {
+    package: "com.first"
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "SOME_BUG"
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+parsed_flag {
+    package: "com.second"
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+    bug: "SOME_BUG"
+    state: ENABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    trace {
+        source: "flags.values"
+        state: ENABLED
+        permission: READ_ONLY
+    }
+    is_fixed_read_only: true
+    container: "system"
+}
+"#;
+        let parsed_flags = try_from_binary_proto_from_text_proto(text_proto).unwrap();
+        assert_eq!(parsed_flags.parsed_flag.len(), 2);
+        let second = parsed_flags.parsed_flag.iter().find(|fv| fv.name() == "second").unwrap();
+        assert_eq!(second.package(), "com.second");
+        assert_eq!(second.name(), "second");
+        assert_eq!(second.namespace(), "second_ns");
+        assert_eq!(second.description(), "This is the description of the second flag.");
+        assert_eq!(second.bug, vec!["SOME_BUG"]);
+        assert_eq!(second.state(), ProtoFlagState::ENABLED);
+        assert_eq!(second.permission(), ProtoFlagPermission::READ_ONLY);
+        assert_eq!(2, second.trace.len());
+        assert_eq!(second.trace[0].source(), "flags.declarations");
+        assert_eq!(second.trace[0].state(), ProtoFlagState::DISABLED);
+        assert_eq!(second.trace[0].permission(), ProtoFlagPermission::READ_ONLY);
+        assert_eq!(second.trace[1].source(), "flags.values");
+        assert_eq!(second.trace[1].state(), ProtoFlagState::ENABLED);
+        assert_eq!(second.trace[1].permission(), ProtoFlagPermission::READ_ONLY);
+        assert!(second.is_fixed_read_only());
+
+        // valid input: empty
+        let parsed_flags = try_from_binary_proto_from_text_proto("").unwrap();
+        assert!(parsed_flags.parsed_flag.is_empty());
+
+        // bad input: empty trace
+        let text_proto = r#"
+parsed_flag {
+    package: "com.first"
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    state: DISABLED
+    permission: READ_ONLY
+    container: "system"
+}
+"#;
+        let error = try_from_binary_proto_from_text_proto(text_proto).unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad parsed flag: empty trace");
+
+        // bad input: missing namespace in parsed_flag
+        let text_proto = r#"
+parsed_flag {
+    package: "com.first"
+    name: "first"
+    description: "This is the description of the first flag."
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let error = try_from_binary_proto_from_text_proto(text_proto).unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad parsed flag: missing namespace");
+
+        // bad input: parsed_flag not sorted by package
+        let text_proto = r#"
+parsed_flag {
+    package: "bbb.bbb"
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: ""
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+parsed_flag {
+    package: "aaa.aaa"
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+    bug: ""
+    state: ENABLED
+    permission: READ_WRITE
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let error = try_from_binary_proto_from_text_proto(text_proto).unwrap_err();
+        assert_eq!(
+            format!("{:?}", error),
+            "bad parsed flags: not sorted: bbb.bbb.first comes before aaa.aaa.second"
+        );
+
+        // bad input: parsed_flag not sorted by name
+        let text_proto = r#"
+parsed_flag {
+    package: "com.foo"
+    name: "bbb"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: ""
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+parsed_flag {
+    package: "com.foo"
+    name: "aaa"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+    bug: ""
+    state: ENABLED
+    permission: READ_WRITE
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let error = try_from_binary_proto_from_text_proto(text_proto).unwrap_err();
+        assert_eq!(
+            format!("{:?}", error),
+            "bad parsed flags: not sorted: com.foo.bbb comes before com.foo.aaa"
+        );
+
+        // bad input: duplicate flags
+        let text_proto = r#"
+parsed_flag {
+    package: "com.foo"
+    name: "bar"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: ""
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+parsed_flag {
+    package: "com.foo"
+    name: "bar"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+    bug: ""
+    state: ENABLED
+    permission: READ_WRITE
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let error = try_from_binary_proto_from_text_proto(text_proto).unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad parsed flags: duplicate flag com.foo.bar (defined in flags.declarations and flags.declarations)");
+    }
+
+    #[test]
+    fn test_parsed_flag_path_to_declaration() {
+        let text_proto = r#"
+parsed_flag {
+    package: "com.foo"
+    name: "bar"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "b/12345678"
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    trace {
+        source: "flags.values"
+        state: ENABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let parsed_flags = try_from_binary_proto_from_text_proto(text_proto).unwrap();
+        let parsed_flag = &parsed_flags.parsed_flag[0];
+        assert_eq!(
+            crate::parsed_flag::path_to_declaration(parsed_flag),
+            "flags.declarations"
+        );
+    }
+
+    #[test]
+    fn test_parsed_flags_merge() {
+        let text_proto = r#"
+parsed_flag {
+    package: "com.first"
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "a"
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+parsed_flag {
+    package: "com.second"
+    name: "second"
+    namespace: "second_ns"
+    description: "This is the description of the second flag."
+    bug: "b"
+    state: ENABLED
+    permission: READ_WRITE
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let expected = try_from_binary_proto_from_text_proto(text_proto).unwrap();
+
+        let text_proto = r#"
+parsed_flag {
+    package: "com.first"
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "a"
+    state: DISABLED
+    permission: READ_ONLY
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let first = try_from_binary_proto_from_text_proto(text_proto).unwrap();
+
+        let text_proto = r#"
+parsed_flag {
+    package: "com.second"
+    name: "second"
+    namespace: "second_ns"
+    bug: "b"
+    description: "This is the description of the second flag."
+    state: ENABLED
+    permission: READ_WRITE
+    trace {
+        source: "flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+    container: "system"
+}
+"#;
+        let second = try_from_binary_proto_from_text_proto(text_proto).unwrap();
+
+        let text_proto = r#"
+parsed_flag {
+    package: "com.second"
+    name: "second"
+    namespace: "second_ns"
+    bug: "b"
+    description: "This is the description of the second flag."
+    state: ENABLED
+    permission: READ_WRITE
+    trace {
+        source: "duplicate/flags.declarations"
+        state: DISABLED
+        permission: READ_ONLY
+    }
+}
+"#;
+        let second_duplicate = try_from_binary_proto_from_text_proto(text_proto).unwrap();
+
+        // bad cases
+
+        // two of the same flag with dedup disabled
+        let error = parsed_flags::merge(vec![first.clone(), first.clone()], false).unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad parsed flags: duplicate flag com.first.first (defined in flags.declarations and flags.declarations)");
+
+        // two conflicting flags with dedup disabled
+        let error =
+            parsed_flags::merge(vec![second.clone(), second_duplicate.clone()], false).unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad parsed flags: duplicate flag com.second.second (defined in flags.declarations and duplicate/flags.declarations)");
+
+        // two conflicting flags with dedup enabled
+        let error =
+            parsed_flags::merge(vec![second.clone(), second_duplicate.clone()], true).unwrap_err();
+        assert_eq!(format!("{:?}", error), "bad parsed flags: duplicate flag com.second.second (defined in flags.declarations and duplicate/flags.declarations)");
+
+        // valid cases
+        assert!(parsed_flags::merge(vec![], false).unwrap().parsed_flag.is_empty());
+        assert!(parsed_flags::merge(vec![], true).unwrap().parsed_flag.is_empty());
+        assert_eq!(first, parsed_flags::merge(vec![first.clone()], false).unwrap());
+        assert_eq!(first, parsed_flags::merge(vec![first.clone()], true).unwrap());
+        assert_eq!(
+            expected,
+            parsed_flags::merge(vec![first.clone(), second.clone()], false).unwrap()
+        );
+        assert_eq!(
+            expected,
+            parsed_flags::merge(vec![first.clone(), second.clone()], true).unwrap()
+        );
+        assert_eq!(
+            expected,
+            parsed_flags::merge(vec![second.clone(), first.clone()], false).unwrap()
+        );
+        assert_eq!(
+            expected,
+            parsed_flags::merge(vec![second.clone(), first.clone()], true).unwrap()
+        );
+
+        // two identical flags with dedup enabled
+        assert_eq!(first, parsed_flags::merge(vec![first.clone(), first.clone()], true).unwrap());
+    }
+}