diff --git a/Cargo.lock b/Cargo.lock
index 889a897410..dd31be0ebd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -127,15 +127,37 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "async-stream"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd56dd203fef61ac097dd65721a419ddccb106b2d2b70ba60a6b529f03961a51"
+dependencies = [
+ "async-stream-impl",
+ "futures-core",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "async-stream-impl"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "16e62a023e7c117e27523144c5d2459f4397fcc3cab0085af8e2224f643a0193"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.15",
+]
+
 [[package]]
 name = "async-trait"
-version = "0.1.52"
+version = "0.1.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "061a7acccaa286c011ddc30970520b98fa40e00c9d644633fb26b5fc63a265e3"
+checksum = "b9ccdd8f2a161be9bd5c023df56f1b2a0bd1d83872ae53b71a84a12c9bf6e842"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 1.0.109",
+ "syn 2.0.15",
 ]
 
 [[package]]
@@ -155,8 +177,8 @@ dependencies = [
  "libc",
  "log",
  "num_enum",
- "prost",
- "prost-build",
+ "prost 0.9.0",
+ "prost-build 0.9.0",
  "rand_core 0.6.4",
  "serde",
  "serde_json",
@@ -185,6 +207,51 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "axum"
+version = "0.6.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8175979259124331c1d7bf6586ee7e0da434155e4b2d48ec2c8386281d8df39"
+dependencies = [
+ "async-trait",
+ "axum-core",
+ "bitflags",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "hyper",
+ "itoa",
+ "matchit",
+ "memchr",
+ "mime",
+ "percent-encoding",
+ "pin-project-lite",
+ "rustversion",
+ "serde",
+ "sync_wrapper",
+ "tower",
+ "tower-layer",
+ "tower-service",
+]
+
+[[package]]
+name = "axum-core"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "759fa577a247914fd3f7f76d62972792636412fbfd634cd452f6a385a74d2d2c"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "mime",
+ "rustversion",
+ "tower-layer",
+ "tower-service",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.64"
@@ -206,6 +273,12 @@ version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
 
+[[package]]
+name = "base64"
+version = "0.21.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a4ddaa51a5bc52a6948f74c06d20aaaddb71924eab79b8c97a8c556e942d6a"
+
 [[package]]
 name = "base64ct"
 version = "1.6.0"
@@ -750,6 +823,15 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "aa9a19cbb55df58761df49b23516a86d432839add4af60fc256da840f66ed35b"
 
+[[package]]
+name = "futures-channel"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3083ce4b914124575708913bca19bfe887522d6e2e6d0952943f5eac4a74010"
+dependencies = [
+ "futures-core",
+]
+
 [[package]]
 name = "futures-core"
 version = "0.3.21"
@@ -767,6 +849,12 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "futures-sink"
+version = "0.3.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f43be4fe21a13b9781a69afa4985b0f6ee0e1afab2c6f454a8cf30e2b2237b6e"
+
 [[package]]
 name = "futures-task"
 version = "0.3.21"
@@ -841,6 +929,25 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 
+[[package]]
+name = "h2"
+version = "0.3.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17f8a914c2987b688368b5138aa05321db91f4090cf26118185672ad588bce21"
+dependencies = [
+ "bytes",
+ "fnv",
+ "futures-core",
+ "futures-sink",
+ "futures-util",
+ "http",
+ "indexmap",
+ "slab",
+ "tokio",
+ "tokio-util",
+ "tracing",
+]
+
 [[package]]
 name = "half"
 version = "1.8.2"
@@ -862,6 +969,12 @@ dependencies = [
  "unicode-segmentation",
 ]
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.19"
@@ -906,6 +1019,76 @@ dependencies = [
  "digest 0.9.0",
 ]
 
+[[package]]
+name = "http"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bd6effc99afb63425aff9b05836f029929e345a6148a14b7ecd5ab67af944482"
+dependencies = [
+ "bytes",
+ "fnv",
+ "itoa",
+]
+
+[[package]]
+name = "http-body"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d5f38f16d184e36f2408a55281cd658ecbd3ca05cce6d6510a176eca393e26d1"
+dependencies = [
+ "bytes",
+ "http",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "httparse"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d897f394bad6a705d5f4104762e116a75639e470d80901eed05a860a95cb1904"
+
+[[package]]
+name = "httpdate"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4a1e36c821dbe04574f602848a19f742f4fb3c98d40449f11bcad18d6b17421"
+
+[[package]]
+name = "hyper"
+version = "0.14.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab302d72a6f11a3b910431ff93aae7e773078c769f0a3ef15fb9ec692ed147d4"
+dependencies = [
+ "bytes",
+ "futures-channel",
+ "futures-core",
+ "futures-util",
+ "h2",
+ "http",
+ "http-body",
+ "httparse",
+ "httpdate",
+ "itoa",
+ "pin-project-lite",
+ "socket2",
+ "tokio",
+ "tower-service",
+ "tracing",
+ "want",
+]
+
+[[package]]
+name = "hyper-timeout"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbb958482e8c7be4bc3cf272a766a2b0bf1a6755e7a6ae777f017a31d11b13b1"
+dependencies = [
+ "hyper",
+ "pin-project-lite",
+ "tokio",
+ "tokio-io-timeout",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.8.0"
@@ -936,9 +1119,9 @@ dependencies = [
 
 [[package]]
 name = "itoa"
-version = "1.0.1"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35"
+checksum = "453ad9f582a441959e5f0d088b02ce04cfe8d51a8eaf077f12ac6d3e94164ca6"
 
 [[package]]
 name = "jni"
@@ -983,9 +1166,9 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.121"
+version = "0.2.142"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "efaa7b300f3b5fe8eb6bf21ce3895e1751d9665086af2d64b42f19701015ff4f"
+checksum = "6a987beff54b60ffa6d51982e1aa1146bc42f19bd26be28b0586f252fccf5317"
 
 [[package]]
 name = "libloading"
@@ -1031,6 +1214,7 @@ dependencies = [
  "serde",
  "sha2",
  "signal-crypto",
+ "signal-grpc",
  "signal-neon-futures",
  "signal-pin",
  "static_assertions",
@@ -1043,7 +1227,7 @@ dependencies = [
 name = "libsignal-bridge-macros"
 version = "0.1.0"
 dependencies = [
- "heck",
+ "heck 0.3.3",
  "proc-macro2",
  "quote",
  "syn 1.0.109",
@@ -1121,8 +1305,8 @@ dependencies = [
  "itertools",
  "log",
  "num_enum",
- "prost",
- "prost-build",
+ "prost 0.9.0",
+ "prost-build 0.9.0",
  "rand 0.7.3",
  "sha2",
  "subtle",
@@ -1170,6 +1354,12 @@ dependencies = [
  "log",
 ]
 
+[[package]]
+name = "matchit"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b87248edafb776e59e6ee64a79086f65890d3510f2c656c000bf2a7e8a0aea40"
+
 [[package]]
 name = "memchr"
 version = "2.4.1"
@@ -1185,6 +1375,12 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "mime"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -1201,6 +1397,18 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "mio"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b9d9a46eff5b4ff64b45a9e316a6d1e0bc719ef429cbec4dc630684212bfdf9"
+dependencies = [
+ "libc",
+ "log",
+ "wasi 0.11.0+wasi-snapshot-preview1",
+ "windows-sys 0.45.0",
+]
+
 [[package]]
 name = "multimap"
 version = "0.8.3"
@@ -1317,6 +1525,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7e5500299e16ebb147ae15a00a942af264cf3688f47923b8fc2cd5858f23ad3"
+
 [[package]]
 name = "oorandom"
 version = "11.1.3"
@@ -1358,6 +1572,12 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
 
+[[package]]
+name = "percent-encoding"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "478c572c3d73181ff3c2539045f6eb99e5491218eae919370993b890cdbdd98e"
+
 [[package]]
 name = "pest"
 version = "2.1.3"
@@ -1377,6 +1597,26 @@ dependencies = [
  "indexmap",
 ]
 
+[[package]]
+name = "pin-project"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ad29a609b6bcd67fee905812e544992d216af9d755757c05ed2d0e15a74c6ecc"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "069bdb1e05adc7a8990dce9cc75370895fbe4e3d58b9b73bf1aee56359344a55"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.8"
@@ -1456,6 +1696,16 @@ version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
 
+[[package]]
+name = "prettyplease"
+version = "0.1.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c8646e95016a7a6c4adea95bafa8a16baab64b583356217f2c85db4a39d9a86"
+dependencies = [
+ "proc-macro2",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "proc-macro-crate"
 version = "1.1.3"
@@ -1502,7 +1752,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "444879275cb4fd84958b1a1d5420d15e6fcf7c235fe47f053c9c2a80aceb6001"
 dependencies = [
  "bytes",
- "prost-derive",
+ "prost-derive 0.9.0",
+]
+
+[[package]]
+name = "prost"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b82eaa1d779e9a4bc1c3217db8ffbeabaae1dca241bf70183242128d48681cd"
+dependencies = [
+ "bytes",
+ "prost-derive 0.11.9",
 ]
 
 [[package]]
@@ -1512,15 +1772,37 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "62941722fb675d463659e49c4f3fe1fe792ff24fe5bbaa9c08cd3b98a1c354f5"
 dependencies = [
  "bytes",
- "heck",
+ "heck 0.3.3",
+ "itertools",
+ "lazy_static",
+ "log",
+ "multimap",
+ "petgraph",
+ "prost 0.9.0",
+ "prost-types 0.9.0",
+ "regex",
+ "tempfile",
+ "which",
+]
+
+[[package]]
+name = "prost-build"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "119533552c9a7ffacc21e099c24a0ac8bb19c2a2a3f363de84cd9b844feab270"
+dependencies = [
+ "bytes",
+ "heck 0.4.1",
  "itertools",
  "lazy_static",
  "log",
  "multimap",
  "petgraph",
- "prost",
- "prost-types",
+ "prettyplease",
+ "prost 0.11.9",
+ "prost-types 0.11.9",
  "regex",
+ "syn 1.0.109",
  "tempfile",
  "which",
 ]
@@ -1538,6 +1820,19 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "prost-derive"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5d2d8d10f3c6ded6da8b05b5fb3b8a5082514344d56c9f871412d29b4e075b4"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "prost-types"
 version = "0.9.0"
@@ -1545,7 +1840,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "534b7a0e836e3c482d2693070f982e39e7611da9695d4d1f5a4b186b51faef0a"
 dependencies = [
  "bytes",
- "prost",
+ "prost 0.9.0",
+]
+
+[[package]]
+name = "prost-types"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "213622a1460818959ac1181aaeb2dc9c7f63df720db7d788b3e24eacd1983e13"
+dependencies = [
+ "prost 0.11.9",
 ]
 
 [[package]]
@@ -1709,6 +2013,21 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "ring"
+version = "0.16.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3053cf52e236a3ed746dfc745aa9cacf1b791d846bdaf412f60a8d7d6e17c8fc"
+dependencies = [
+ "cc",
+ "libc",
+ "once_cell",
+ "spin",
+ "untrusted",
+ "web-sys",
+ "winapi",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.21"
@@ -1730,6 +2049,43 @@ dependencies = [
  "semver 0.11.0",
 ]
 
+[[package]]
+name = "rustls"
+version = "0.21.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c911ba11bc8433e811ce56fde130ccf32f5127cab0e0194e9c68c5a5b671791e"
+dependencies = [
+ "log",
+ "ring",
+ "rustls-webpki",
+ "sct",
+]
+
+[[package]]
+name = "rustls-pemfile"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d194b56d58803a43635bdc398cd17e383d6f71f9182b9a192c127ca42494a59b"
+dependencies = [
+ "base64 0.21.0",
+]
+
+[[package]]
+name = "rustls-webpki"
+version = "0.100.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6207cd5ed3d8dca7816f8f3725513a34609c0c765bf652b8c3cb4cfd87db46b"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
+[[package]]
+name = "rustversion"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4f3208ce4d8448b3f3e7d168a73f5e0c43a61e32930de3bceeccedb388b6bf06"
+
 [[package]]
 name = "rusty-fork"
 version = "0.3.0"
@@ -1763,6 +2119,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "sct"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d53dcdb7c9f8158937a7981b48accfd39a43af418591a5d008c7b22b5e1b7ca4"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
 [[package]]
 name = "semver"
 version = "0.9.0"
@@ -1877,6 +2243,18 @@ dependencies = [
  "subtle",
 ]
 
+[[package]]
+name = "signal-grpc"
+version = "0.1.0"
+dependencies = [
+ "displaydoc",
+ "prost 0.11.9",
+ "thiserror",
+ "tokio",
+ "tonic",
+ "tonic-build",
+]
+
 [[package]]
 name = "signal-neon-futures"
 version = "0.1.0"
@@ -1939,6 +2317,22 @@ dependencies = [
  "x25519-dalek",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64a4a911eed85daf18834cfaa86a79b7d266ff93ff5ba14005426219480ed662"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
+
 [[package]]
 name = "static_assertions"
 version = "1.1.0"
@@ -1984,6 +2378,12 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "sync_wrapper"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
+
 [[package]]
 name = "synstructure"
 version = "0.12.6"
@@ -2057,6 +2457,78 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "tokio"
+version = "1.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3c786bf8134e5a3a166db9b29ab8f48134739014a3eca7bc6bfa95d673b136f"
+dependencies = [
+ "autocfg",
+ "bytes",
+ "libc",
+ "mio",
+ "pin-project-lite",
+ "socket2",
+ "tokio-macros",
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "tokio-io-timeout"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30b74022ada614a1b4834de765f9bb43877f910cc8ce4be40e89042c9223a8bf"
+dependencies = [
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "630bdcf245f78637c13ec01ffae6187cca34625e8c63150d424b59e55af2675e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.15",
+]
+
+[[package]]
+name = "tokio-rustls"
+version = "0.24.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e0d409377ff5b1e3ca6437aa86c1eb7d40c134bfec254e44c830defa92669db5"
+dependencies = [
+ "rustls",
+ "tokio",
+]
+
+[[package]]
+name = "tokio-stream"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "397c988d37662c7dda6d2208364a706264bf3d6138b11d436cbac0ad38832842"
+dependencies = [
+ "futures-core",
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "tokio-util"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "806fe8c2c87eccc8b3267cbae29ed3ab2d0bd37fca70ab622e46aaa9375ddb7d"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "toml"
 version = "0.5.8"
@@ -2066,6 +2538,121 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "tonic"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3082666a3a6433f7f511c7192923fa1fe07c69332d3c6a2e6bb040b569199d5a"
+dependencies = [
+ "async-stream",
+ "async-trait",
+ "axum",
+ "base64 0.21.0",
+ "bytes",
+ "futures-core",
+ "futures-util",
+ "h2",
+ "http",
+ "http-body",
+ "hyper",
+ "hyper-timeout",
+ "percent-encoding",
+ "pin-project",
+ "prost 0.11.9",
+ "rustls-pemfile",
+ "tokio",
+ "tokio-rustls",
+ "tokio-stream",
+ "tower",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+ "webpki-roots",
+]
+
+[[package]]
+name = "tonic-build"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6fdaae4c2c638bb70fe42803a26fbd6fc6ac8c72f5c59f67ecc2a2dcabf4b07"
+dependencies = [
+ "prettyplease",
+ "proc-macro2",
+ "prost-build 0.11.9",
+ "quote",
+ "syn 1.0.109",
+]
+
+[[package]]
+name = "tower"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8fa9be0de6cf49e536ce1851f987bd21a43b771b09473c3549a6c853db37c1c"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "indexmap",
+ "pin-project",
+ "pin-project-lite",
+ "rand 0.8.5",
+ "slab",
+ "tokio",
+ "tokio-util",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c20c8dbed6283a09604c3e69b4b7eeb54e298b8a600d4d5ecb5ad39de609f1d0"
+
+[[package]]
+name = "tower-service"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6bc1c9ce2b5135ac7f93c72918fc37feb872bdc6a5533a8b85eb4b86bfdae52"
+
+[[package]]
+name = "tracing"
+version = "0.1.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a400e31aa60b9d44a52a8ee0343b5b18566b03a8321e0d321f695cf56e940160"
+dependencies = [
+ "cfg-if",
+ "pin-project-lite",
+ "tracing-attributes",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-attributes"
+version = "0.1.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f57e3ca2a01450b1a921183a9c9cbfda207fd822cef4ccb00a65402cbba7a74"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.15",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24eb03ba0eab1fd845050058ce5e616558e8f8d8fca633e6b163fe25c797213a"
+dependencies = [
+ "once_cell",
+]
+
+[[package]]
+name = "try-lock"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3528ecfd12c466c6f163363caf2d02a71161dd5e1cc6ae7b34207ea2d42d81ed"
+
 [[package]]
 name = "typenum"
 version = "1.15.0"
@@ -2106,6 +2693,12 @@ dependencies = [
  "subtle",
 ]
 
+[[package]]
+name = "untrusted"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a156c684c91ea7d62626509bce3cb4e1d9ed5c4d978f7b4352658f96a4c26b4a"
+
 [[package]]
 name = "unzip3"
 version = "1.0.0"
@@ -2169,6 +2762,16 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "want"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ce8a968cb1cd110d136ff8b819a556d6fb6d919363c61534f6860c7eb172ba0"
+dependencies = [
+ "log",
+ "try-lock",
+]
+
 [[package]]
 name = "wasi"
 version = "0.9.0+wasi-snapshot-preview1"
@@ -2181,6 +2784,12 @@ version = "0.10.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1a143597ca7c7793eff794def352d41792a93c481eb1042423ff7ff72ba2c31f"
 
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.79"
@@ -2245,6 +2854,15 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webpki-roots"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa54963694b65584e170cf5dc46aeb4dcaa5584e652ff5f3952e56d66aff0125"
+dependencies = [
+ "rustls-webpki",
+]
+
 [[package]]
 name = "which"
 version = "4.2.4"
@@ -2287,6 +2905,138 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "windows-sys"
+version = "0.45.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75283be5efb2831d37ea142365f009c02ec203cd29a3ebecbc093d52315b66d0"
+dependencies = [
+ "windows-targets 0.42.2",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
+dependencies = [
+ "windows-targets 0.48.0",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e5180c00cd44c9b1c88adb3693291f1cd93605ded80c250a75d472756b4d071"
+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-targets"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b1eb6f0cd7c80c79759c929114ef071b87354ce476d9d94271031c0497adfd5"
+dependencies = [
+ "windows_aarch64_gnullvm 0.48.0",
+ "windows_aarch64_msvc 0.48.0",
+ "windows_i686_gnu 0.48.0",
+ "windows_i686_msvc 0.48.0",
+ "windows_x86_64_gnu 0.48.0",
+ "windows_x86_64_gnullvm 0.48.0",
+ "windows_x86_64_msvc 0.48.0",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "597a5118570b68bc08d8d59125332c54f1ba9d9adeedeef5b99b02ba2b0698f8"
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91ae572e1b79dba883e0d315474df7305d12f569b400fcf90581b06062f7e1bc"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e08e8864a60f06ef0d0ff4ba04124db8b0fb3be5776a5cd47641e942e58c4d43"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2ef27e0d7bdfcfc7b868b317c1d32c641a6fe4629c171b8928c7b08d98d7cf3"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c61d927d8da41da96a81f029489353e68739737d3beca43145c8afec9a31a84f"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "622a1962a7db830d6fd0a69683c80a18fda201879f0f447f065a3b7467daa241"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44d840b6ec649f480a41c8d80f9c65108b92d89345dd94027bfe06ac444d1060"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4542c6e364ce21bf45d69fdd2a8e455fa38d316158cfd43b3ac1c5b1b19f8e00"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8de912b8b8feb55c064867cf047dda097f92d51efad5b491dfb98f6bbb70cb36"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca2b8a661f7628cbd23440e50b05d705db3686f894fc9580820623656af974b1"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "26d41b46a36d453748aedef1486d5c7a85db22e56aff34643984ea85514e94a3"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7896dbc1f41e08872e9d5e8f8baa8fdd2677f29468c4e156210174edc7f7b953"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.42.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9aec5da331524158c6d1a4ac0ab1541149c0b9505fde06423b02f5ef0106b9f0"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a515f5799fe4961cb532f983ce2b23082366b898e52ffbce459c86f67c8378a"
+
 [[package]]
 name = "x25519-dalek"
 version = "1.1.1"
@@ -2338,7 +3088,7 @@ version = "0.9.0"
 dependencies = [
  "aead",
  "aes-gcm-siv",
- "base64",
+ "base64 0.13.0",
  "bincode",
  "criterion",
  "curve25519-dalek",
diff --git a/Cargo.toml b/Cargo.toml
index cd6ab3afa9..1980ed2a75 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,6 +3,7 @@ members = [
     "rust/attest",
     "rust/crypto",
     "rust/device-transfer",
+    "rust/grpc",
     "rust/pin",
     "rust/poksho",
     "rust/protocol",
diff --git a/java/build.gradle b/java/build.gradle
index 5ecaa6aeee..0521f524bc 100644
--- a/java/build.gradle
+++ b/java/build.gradle
@@ -2,7 +2,7 @@ plugins {
     id "de.undercouch.download" version "5.0.2"
 }
 
-def version_number = "0.23.0"
+def version_number = "0.23.0-gluon-1"
 
 subprojects {
     ext.version_number     = version_number
diff --git a/java/gradle/wrapper/gradle-wrapper.jar b/java/gradle/wrapper/gradle-wrapper.jar
index 5c2d1cf016..41d9927a4d 100644
Binary files a/java/gradle/wrapper/gradle-wrapper.jar and b/java/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/java/gradle/wrapper/gradle-wrapper.properties b/java/gradle/wrapper/gradle-wrapper.properties
index a0c86dbe85..774fae8767 100644
--- a/java/gradle/wrapper/gradle-wrapper.properties
+++ b/java/gradle/wrapper/gradle-wrapper.properties
@@ -1,7 +1,5 @@
-# Note: Check https://gradle.org/release-checksums/ before updating wrapper or distribution
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionSha256Sum=8cc27038d5dbd815759851ba53e70cf62e481b87494cc97cfd97982ada5ba634
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/java/gradlew b/java/gradlew
index 83f2acfdc3..1b6c787337 100755
--- a/java/gradlew
+++ b/java/gradlew
@@ -1,7 +1,7 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 #
-# Copyright 2015 the original author or authors.
+# Copyright © 2015-2021 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,78 +17,113 @@
 #
 
 ##############################################################################
-##
-##  Gradle start up script for UN*X
-##
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
 ##############################################################################
 
 # Attempt to set APP_HOME
+
 # Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
 
 APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
+APP_BASE_NAME=${0##*/}
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
+MAX_FD=maximum
 
 warn () {
     echo "$*"
-}
+} >&2
 
 die () {
     echo
     echo "$*"
     echo
     exit 1
-}
+} >&2
 
 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
 nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
 esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
         # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
+        JAVACMD=$JAVA_HOME/jre/sh/java
     else
-        JAVACMD="$JAVA_HOME/bin/java"
+        JAVACMD=$JAVA_HOME/bin/java
     fi
     if [ ! -x "$JAVACMD" ] ; then
         die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -97,7 +132,7 @@ Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
     fi
 else
-    JAVACMD="java"
+    JAVACMD=java
     which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
@@ -105,84 +140,95 @@ location of your Java installation."
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
 fi
 
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
 
 # For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
     # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
         fi
-        i=$((i+1))
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
     done
-    case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
-    esac
 fi
 
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=$(save "$@")
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
 
-# Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
 
-# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
-if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
-  cd "$(dirname "$0")"
-fi
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
 
 exec "$JAVACMD" "$@"
diff --git a/java/gradlew.bat b/java/gradlew.bat
index 24467a141f..ac1b06f938 100644
--- a/java/gradlew.bat
+++ b/java/gradlew.bat
@@ -29,6 +29,9 @@ if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 
@@ -37,7 +40,7 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto init
+if "%ERRORLEVEL%" == "0" goto execute
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -51,7 +54,7 @@ goto fail
 set JAVA_HOME=%JAVA_HOME:"=%
 set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
-if exist "%JAVA_EXE%" goto init
+if exist "%JAVA_EXE%" goto execute
 
 echo.
 echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
@@ -61,28 +64,14 @@ echo location of your Java installation.
 
 goto fail
 
-:init
-@rem Get command-line arguments, handling Windows variants
-
-if not "%OS%" == "Windows_NT" goto win9xME_args
-
-:win9xME_args
-@rem Slurp the command line arguments.
-set CMD_LINE_ARGS=
-set _SKIP=2
-
-:win9xME_args_slurp
-if "x%~1" == "x" goto execute
-
-set CMD_LINE_ARGS=%*
-
 :execute
 @rem Setup the command line
 
 set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
+
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
 
 :end
 @rem End local scope for the variables with windows NT shell
diff --git a/java/shared/java/org/signal/libsignal/grpc/GrpcClient.java b/java/shared/java/org/signal/libsignal/grpc/GrpcClient.java
new file mode 100644
index 0000000000..d502aacb6e
--- /dev/null
+++ b/java/shared/java/org/signal/libsignal/grpc/GrpcClient.java
@@ -0,0 +1,26 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+package org.signal.libsignal.grpc;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+import org.signal.libsignal.internal.Native;
+
+public class GrpcClient {
+
+  public SignalRpcReply sendMessage(SignalRpcMessage message) {
+    byte[] reply = Native.Grpc_SendMessage(message.getMethod(), message.getUrlFragment(), message.getBody(), message.getHeaders());
+
+    SignalRpcReply signalRpcReply = new SignalRpcReply();
+
+    ByteBuffer replyBuffer = ByteBuffer.wrap(reply, 0, 4);
+    signalRpcReply.setStatusCode(replyBuffer.getInt());
+
+    signalRpcReply.setMessage(new String(reply, 4, reply.length - 4, StandardCharsets.UTF_8));
+    return signalRpcReply;
+  }
+}
diff --git a/java/shared/java/org/signal/libsignal/grpc/SignalRpcMessage.java b/java/shared/java/org/signal/libsignal/grpc/SignalRpcMessage.java
new file mode 100644
index 0000000000..700134c3fe
--- /dev/null
+++ b/java/shared/java/org/signal/libsignal/grpc/SignalRpcMessage.java
@@ -0,0 +1,59 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+package org.signal.libsignal.grpc;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+public class SignalRpcMessage {
+
+  private String method;
+  private String urlFragment;
+  private byte[] body;
+  private Map<String, List<String>> headers;
+
+  public SignalRpcMessage() {
+    this.headers = new HashMap<>();
+  }
+
+  public String getMethod() {
+    return method;
+  }
+
+  public void setMethod(String method) {
+    this.method = method;
+  }
+
+  public byte[] getBody() {
+    return body;
+  }
+
+  public void setBody(byte[] body) {
+    this.body = body;
+  }
+
+  public String getUrlFragment() {
+    return urlFragment;
+  }
+
+  public void setUrlFragment(String urlFragment) {
+    this.urlFragment = urlFragment;
+  }
+
+  public Map<String, List<String>> getHeaders() {
+    return headers;
+  }
+
+  public void setHeaders(Map<String, List<String>> headers) {
+    this.headers = headers;
+  }
+
+  public void header(String headerKey, String headerValue) {
+    this.headers.computeIfAbsent(headerKey, key -> new LinkedList<>()).add(headerValue);
+  }
+}
diff --git a/java/shared/java/org/signal/libsignal/grpc/SignalRpcReply.java b/java/shared/java/org/signal/libsignal/grpc/SignalRpcReply.java
new file mode 100644
index 0000000000..c7ee6ba424
--- /dev/null
+++ b/java/shared/java/org/signal/libsignal/grpc/SignalRpcReply.java
@@ -0,0 +1,28 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+package org.signal.libsignal.grpc;
+
+public class SignalRpcReply {
+
+  private int statusCode;
+  private String message;
+
+  public int getStatusCode() {
+    return statusCode;
+  }
+
+  public void setStatusCode(int statusCode) {
+    this.statusCode = statusCode;
+  }
+
+  public String getMessage() {
+    return message;
+  }
+
+  public void setMessage(String message) {
+    this.message = message;
+  }
+}
diff --git a/java/shared/java/org/signal/libsignal/internal/Native.java b/java/shared/java/org/signal/libsignal/internal/Native.java
index 96865b90c5..e746173c05 100644
--- a/java/shared/java/org/signal/libsignal/internal/Native.java
+++ b/java/shared/java/org/signal/libsignal/internal/Native.java
@@ -22,6 +22,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.file.Files;
+import java.util.List;
 import java.util.UUID;
 import java.util.Map;
 
@@ -487,4 +488,6 @@ private Native() {}
   public static native void Username_Verify(byte[] proof, byte[] hash);
 
   public static native void UuidCiphertext_CheckValidContents(byte[] buffer);
+
+  public static native byte[] Grpc_SendMessage(String method, String urlFragment, byte[] body, Map<String, List<String>> headers);
 }
diff --git a/rust/bridge/shared/Cargo.toml b/rust/bridge/shared/Cargo.toml
index 580cf27005..45269895b5 100644
--- a/rust/bridge/shared/Cargo.toml
+++ b/rust/bridge/shared/Cargo.toml
@@ -19,6 +19,7 @@ zkgroup = { path = "../../zkgroup" }
 usernames = { path = "../../usernames" }
 signal-pin = { path = "../../pin" }
 libsignal-bridge-macros = { path = "macros" }
+signal-grpc = { path = "../../grpc" }
 aes-gcm-siv = "0.10.1"
 async-trait = "0.1.41"
 bincode = "1.0"
diff --git a/rust/bridge/shared/src/grpc.rs b/rust/bridge/shared/src/grpc.rs
new file mode 100644
index 0000000000..e3f0e5255e
--- /dev/null
+++ b/rust/bridge/shared/src/grpc.rs
@@ -0,0 +1,21 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+use ::signal_grpc::GrpcClient;
+use ::signal_grpc::Result;
+use libsignal_bridge_macros::*;
+
+use crate::support::*;
+use crate::*;
+
+use std::collections::HashMap;
+
+#[cfg(all(feature = "jni"))]
+pub struct GrpcHeaders(pub HashMap<String, Vec<String>>);
+
+#[bridge_fn(ffi = false, node = false)]
+pub fn Grpc_SendMessage(method: String, url_fragment: String, body: &[u8], headers: GrpcHeaders) -> Result<Vec<u8>> {
+    GrpcClient::new()?.send_message(method, url_fragment, body, headers.0)
+}
diff --git a/rust/bridge/shared/src/jni/convert.rs b/rust/bridge/shared/src/jni/convert.rs
index 70324e530a..5d45ec8392 100644
--- a/rust/bridge/shared/src/jni/convert.rs
+++ b/rust/bridge/shared/src/jni/convert.rs
@@ -8,6 +8,7 @@ use jni::sys::{jbyte, JNI_FALSE, JNI_TRUE};
 use jni::JNIEnv;
 use libsignal_protocol::*;
 use paste::paste;
+use std::collections::HashMap;
 use std::convert::TryInto;
 use std::ops::Deref;
 
@@ -414,6 +415,34 @@ impl<'a> SimpleArgTypeInfo<'a> for CiphertextMessageRef<'a> {
     }
 }
 
+impl<'a> SimpleArgTypeInfo<'a> for crate::grpc::GrpcHeaders {
+    type ArgType = JavaArgMap<'a>;
+    fn convert_from(env: &JNIEnv, foreign: Self::ArgType) -> SignalJniResult<Self> {
+        if foreign.is_null() {
+            return Err(SignalJniError::NullHandle);
+        }
+
+        let mut headers = HashMap::new();
+
+        let jmap = env.get_map(foreign)?;
+        let mut jmap_iter = jmap.iter()?;
+        while let Some((key, value)) = jmap_iter.next() {
+            let header_key: String = env.get_string(key.into())?.into();
+            let values = env.get_list(value)?;
+            let mut values_iter = values.iter()?;
+            while let Some(value) = values_iter.next() {
+                let header_value: String = env.get_string(value.into())?.into();
+                headers
+                    .entry(header_key.clone())
+                    .and_modify(|l: &mut Vec<String>| l.push(header_value.clone()))
+                    .or_insert_with(move || vec![header_value]);
+            }
+        }
+
+        Ok(crate::grpc::GrpcHeaders(headers))
+    }
+}
+
 #[cfg(not(target_os = "android"))]
 impl ResultTypeInfo for crate::cds2::Cds2Metrics {
     type ResultType = jobject;
@@ -748,6 +777,16 @@ impl<T: ResultTypeInfo> ResultTypeInfo for Result<T, device_transfer::Error> {
     }
 }
 
+impl<T: ResultTypeInfo> ResultTypeInfo for Result<T, signal_grpc::Error> {
+    type ResultType = T::ResultType;
+    fn convert_into(self, env: &JNIEnv) -> SignalJniResult<Self::ResultType> {
+        T::convert_into(self?, env)
+    }
+    fn convert_into_jobject(signal_jni_result: &SignalJniResult<Self::ResultType>) -> JObject {
+        <T as ResultTypeInfo>::convert_into_jobject(signal_jni_result)
+    }
+}
+
 impl<T: ResultTypeInfo> ResultTypeInfo for Result<T, attest::hsm_enclave::Error> {
     type ResultType = T::ResultType;
     fn convert_into(self, env: &JNIEnv) -> SignalJniResult<Self::ResultType> {
@@ -1091,6 +1130,9 @@ macro_rules! jni_arg_type {
     (Uuid) => {
         jni::JavaUUID
     };
+    (GrpcHeaders) => {
+        jni::JavaArgMap
+    };
     (jni::CiphertextMessageRef) => {
         jni::JavaCiphertextMessage
     };
diff --git a/rust/bridge/shared/src/jni/error.rs b/rust/bridge/shared/src/jni/error.rs
index 02aa31726c..9051a9a39e 100644
--- a/rust/bridge/shared/src/jni/error.rs
+++ b/rust/bridge/shared/src/jni/error.rs
@@ -9,6 +9,7 @@ use std::fmt;
 
 use attest::hsm_enclave::Error as HsmEnclaveError;
 use device_transfer::Error as DeviceTransferError;
+use signal_grpc::Error as GrpcError;
 use libsignal_protocol::*;
 use signal_crypto::Error as SignalCryptoError;
 use signal_pin::Error as PinError;
@@ -24,6 +25,7 @@ use super::*;
 pub enum SignalJniError {
     Signal(SignalProtocolError),
     DeviceTransfer(DeviceTransferError),
+    Grpc(GrpcError),
     SignalCrypto(SignalCryptoError),
     HsmEnclave(HsmEnclaveError),
     Sgx(SgxError),
@@ -45,6 +47,7 @@ impl fmt::Display for SignalJniError {
         match self {
             SignalJniError::Signal(s) => write!(f, "{}", s),
             SignalJniError::DeviceTransfer(s) => write!(f, "{}", s),
+            SignalJniError::Grpc(e) => write!(f, "{}", e),
             SignalJniError::HsmEnclave(e) => write!(f, "{}", e),
             SignalJniError::Sgx(e) => write!(f, "{}", e),
             SignalJniError::Pin(e) => write!(f, "{}", e),
@@ -87,6 +90,12 @@ impl From<DeviceTransferError> for SignalJniError {
     }
 }
 
+impl From<GrpcError> for SignalJniError {
+    fn from(e: GrpcError) -> SignalJniError {
+        SignalJniError::Grpc(e)
+    }
+}
+
 impl From<HsmEnclaveError> for SignalJniError {
     fn from(e: HsmEnclaveError) -> SignalJniError {
         SignalJniError::HsmEnclave(e)
diff --git a/rust/bridge/shared/src/jni/mod.rs b/rust/bridge/shared/src/jni/mod.rs
index f63252b5e7..b54e09b7bc 100644
--- a/rust/bridge/shared/src/jni/mod.rs
+++ b/rust/bridge/shared/src/jni/mod.rs
@@ -42,6 +42,7 @@ pub type ObjectHandle = jlong;
 
 pub type JavaObject<'a> = JObject<'a>;
 pub type JavaUUID<'a> = JObject<'a>;
+pub type JavaArgMap<'a> = JObject<'a>;
 pub type JavaReturnUUID = jobject;
 pub type JavaCiphertextMessage<'a> = JObject<'a>;
 pub type JavaReturnCiphertextMessage = jobject;
@@ -220,7 +221,8 @@ fn throw_error(env: &JNIEnv, error: SignalJniError) {
         | SignalJniError::Signal(SignalProtocolError::ApplicationCallbackError(_, _))
         | SignalJniError::Signal(SignalProtocolError::FfiBindingError(_))
         | SignalJniError::DeviceTransfer(DeviceTransferError::InternalError(_))
-        | SignalJniError::DeviceTransfer(DeviceTransferError::KeyDecodingFailed) => {
+        | SignalJniError::DeviceTransfer(DeviceTransferError::KeyDecodingFailed)
+        | SignalJniError::Grpc(_) => {
             jni_class_name!(java.lang.RuntimeException)
         }
 
diff --git a/rust/bridge/shared/src/lib.rs b/rust/bridge/shared/src/lib.rs
index 53a4c97aae..e43f52cf31 100644
--- a/rust/bridge/shared/src/lib.rs
+++ b/rust/bridge/shared/src/lib.rs
@@ -28,6 +28,9 @@ pub use support::describe_panic;
 pub mod crypto;
 pub mod protocol;
 
+#[cfg(feature = "jni")]
+pub mod grpc;
+
 // Desktop does not make use of device transfer certificates
 #[cfg(any(feature = "jni", feature = "ffi"))]
 pub mod device_transfer;
diff --git a/rust/grpc/Cargo.toml b/rust/grpc/Cargo.toml
new file mode 100644
index 0000000000..2a7cf46709
--- /dev/null
+++ b/rust/grpc/Cargo.toml
@@ -0,0 +1,21 @@
+#
+# Copyright (C) 2023 Signal Messenger, LLC.
+# SPDX-License-Identifier: AGPL-3.0-only
+#
+
+[package]
+name = "signal-grpc"
+version = "0.1.0"
+authors = ["Signal Messenger LLC"]
+edition = "2021"
+license = "AGPL-3.0-only"
+
+[dependencies]
+displaydoc = "0.2"
+prost = "0.11"
+thiserror = "1.0.30"
+tokio = { version = "1.28", features = [ "rt" ] }
+tonic = { version = "0.9", features = [ "tls", "tls-webpki-roots" ] }
+
+[build-dependencies]
+tonic-build = "0.9"
diff --git a/rust/grpc/build.rs b/rust/grpc/build.rs
new file mode 100644
index 0000000000..b164efc832
--- /dev/null
+++ b/rust/grpc/build.rs
@@ -0,0 +1,19 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let protos = [
+        "src/proto/proxy.proto",
+    ];
+    tonic_build::configure()
+        .build_server(false).compile(
+        &protos,
+        &["src"],
+    )?;
+    for proto in &protos {
+        println!("cargo:rerun-if-changed={}", proto);
+    }
+    Ok(())
+}
diff --git a/rust/grpc/src/client.rs b/rust/grpc/src/client.rs
new file mode 100644
index 0000000000..ca8c146e66
--- /dev/null
+++ b/rust/grpc/src/client.rs
@@ -0,0 +1,58 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+use crate::{error::{Error, Result}, proto};
+use std::collections::HashMap;
+
+pub struct GrpcClient {
+    tokio_runtime: tokio::runtime::Runtime,
+}
+
+impl GrpcClient {
+    pub fn new() -> Result<Self> {
+        Ok(GrpcClient {
+            tokio_runtime: tokio::runtime::Builder::new_current_thread()
+                .enable_io()
+                .build()
+                .map_err(|e| Error::InvalidArgument(format!("tokio.create_runtime: {:?}", e)))?
+        })
+    }
+
+    pub fn send_message(&self, method: String, url_fragment: String, body: &[u8], headers: HashMap<String, Vec<String>>) -> Result<Vec<u8>> {
+        println!("Tunneling gRPC message: method={} url_fragment={}, body.len={}, headers={:?}", method, url_fragment, body.len(), headers);
+        self.tokio_runtime.block_on(async {
+            self.tunnel_message(method, url_fragment, body, headers).await
+        })
+    }
+
+    async fn tunnel_message(&self, method: String, url_fragment: String, body: &[u8], headers: HashMap<String, Vec<String>>) -> Result<Vec<u8>> {
+        let mut tunnel = proto::proxy::tunnel_client::TunnelClient::connect("https://grpcproxy.gluonhq.net:443").await
+            .map_err(|e| Error::InvalidArgument(format!("tunnel.connect: {:?}", e)))?;
+
+        let mut request_headers = vec![];
+        for (header_name, header_values) in headers.iter() {
+            for header_value in header_values.iter() {
+                request_headers.push(format!("{}={}", header_name, header_value))
+            }
+        }
+
+        let request = proto::proxy::SignalRpcMessage {
+            body: body.to_vec(),
+            method,
+            urlfragment: url_fragment,
+            header: request_headers,
+        };
+
+        let response = tunnel.send_some_message(request).await
+            .map_err(|e| Error::InvalidArgument(format!("tunnel.send_some_message: {:?}", e)))?;
+
+        let mut result = vec![];
+
+        result.extend(response.get_ref().statuscode.to_be_bytes());
+        result.extend(response.get_ref().message.as_bytes());
+
+        Ok(result)
+    }
+}
diff --git a/rust/grpc/src/error.rs b/rust/grpc/src/error.rs
new file mode 100644
index 0000000000..9398c8c38a
--- /dev/null
+++ b/rust/grpc/src/error.rs
@@ -0,0 +1,15 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+use displaydoc::Display;
+use thiserror::Error;
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug, Display, Error)]
+pub enum Error {
+    /// invalid argument: {0}
+    InvalidArgument(String),
+}
diff --git a/rust/grpc/src/lib.rs b/rust/grpc/src/lib.rs
new file mode 100644
index 0000000000..fb9a8b54b1
--- /dev/null
+++ b/rust/grpc/src/lib.rs
@@ -0,0 +1,12 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+mod client;
+mod error;
+mod proto;
+
+pub use client::GrpcClient;
+pub use error::{Error, Result};
+
diff --git a/rust/grpc/src/proto.rs b/rust/grpc/src/proto.rs
new file mode 100644
index 0000000000..d8590b470c
--- /dev/null
+++ b/rust/grpc/src/proto.rs
@@ -0,0 +1,6 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+pub mod proxy;
diff --git a/rust/grpc/src/proto/proxy.proto b/rust/grpc/src/proto/proxy.proto
new file mode 100644
index 0000000000..95bd7ca8e8
--- /dev/null
+++ b/rust/grpc/src/proto/proxy.proto
@@ -0,0 +1,24 @@
+syntax = "proto3";
+
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+package signal.grpc.proxy;
+
+service Tunnel {
+    rpc SendSomeMessage (SignalRpcMessage) returns (SignalRpcReply) {}
+}
+
+message SignalRpcMessage {
+  string urlfragment = 1;
+  string method = 2;
+  repeated string header = 3;
+  bytes body = 4;
+}
+
+message SignalRpcReply {
+  int32 statuscode = 1;
+  string message = 2;
+}
diff --git a/rust/grpc/src/proto/proxy.rs b/rust/grpc/src/proto/proxy.rs
new file mode 100644
index 0000000000..a19f4b39e2
--- /dev/null
+++ b/rust/grpc/src/proto/proxy.rs
@@ -0,0 +1,8 @@
+//
+// Copyright 2023 Signal Messenger, LLC.
+// SPDX-License-Identifier: AGPL-3.0-only
+//
+
+#![allow(clippy::derive_partial_eq_without_eq)]
+
+include!(concat!(env!("OUT_DIR"), "/signal.grpc.proxy.rs"));