Update rust SDK to use new Hegel protocol

.claude/CLAUDE.md

@@ -22,7 +22,8 @@ cargo test --all-features           # Run tests including optional features
 hegel-rust/
 ├── src/
 │   ├── lib.rs          # Public API: hegel(), Hegel builder, assume(), note()
-│   ├── embedded.rs     # Spawns hegel CLI, manages socket server
+│   ├── cbor_helpers.rs # Macros and helpers for ciborium::Value (cbor_map!, cbor_array!, map_get, etc.)
+│   ├── runner.rs       # Spawns hegel CLI, manages socket server
 │   └── gen/            # Generator implementations
 │       ├── mod.rs      # Generate trait, socket communication, thread-local state
 │       ├── primitives.rs   # unit(), booleans(), just(), just_any()
@@ -55,16 +56,16 @@ hegel-rust/
 
 ### How It Works
 
-The SDK spawns the `hegel` CLI as a subprocess with `--client-mode`. The test binary creates a Unix socket server, and hegel connects for each test case. The build script (`build.rs`) automatically installs Python and hegel into cargo's `OUT_DIR/hegel` via uv if not found on PATH.
+The SDK creates a socket path and spawns the `hegel` CLI as a subprocess. Hegeld binds to the socket and listens for connections. The SDK then connects as a client, and a single persistent connection is maintained for the program run. Multiple tests can be executed over this connection. The build script (`build.rs`) automatically installs Python and hegel into cargo's `OUT_DIR/hegel` via uv if not found on PATH.
 
 ### Protocol
 
-Each test case follows this handshake:
-1. Hegel connects to the SDK's socket
-2. Hegel sends: `{"is_last_run": bool}` (is_last_run=true on final replay for output)
-3. SDK responds: `{"type": "handshake_ack"}`
-4. SDK runs test, communicating via `generate`/`start_span`/`stop_span` commands
-5. SDK sends result: `{"type": "test_result", "result": "pass"|"fail"|"reject", ...}`
+The protocol uses CBOR encoding over multiplexed channels. For each test:
+1. SDK sends `run_test` request on control channel
+2. Hegeld sends `test_case` events with channel IDs for each test case
+3. SDK runs test function, sending `generate`/`start_span`/`stop_span` requests on the test channel
+4. SDK sends `mark_complete` with status (VALID, INVALID, or INTERESTING)
+5. After all test cases, hegeld sends `test_done` with results`
 
 ### Thread-Local State
 
@@ -75,7 +76,7 @@ The SDK uses thread-local storage for:
 ### Generation Protocol
 
 Generators implement the `Generate<T>` trait:
-- `schema()`: Returns JSON Schema describing generated values (enables single-request composition)
+- `schema()`: Returns a CBOR schema (as `ciborium::Value`) describing generated values (enables single-request composition)
 - `generate()`: Produces a value, either via schema or compositional fallback
 
 When `schema()` returns `Some`, the SDK sends one request. When `None` (after `map`/`filter`), it falls back to multiple requests with span grouping for shrinking.

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
     strategy:
       matrix:
         # keep this in sync with the rust-version in cargo.toml
-        rust: ["1.68", stable]
+        rust: ["1.81", stable]
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/base
@@ -46,7 +46,7 @@ jobs:
     strategy:
       matrix:
         # keep this in sync with the rust-version in cargo.toml
-        rust: ["1.68", stable]
+        rust: ["1.81", stable]
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/base
@@ -102,7 +102,7 @@ jobs:
           python-version: '3.13'
       - name: Install hegel
         run: |
-          pip install git+ssh://git@github.com/antithesishq/hegel.git
+          pip install git+ssh://git@github.com/antithesishq/hegel.git@main
           pip install pytest
       - name: Build conformance binaries
         working-directory: tests/conformance/rust

.gitignore

@@ -8,5 +8,13 @@
 .hegel
 __pycache__
 target/
-.claude/settings.local.json
+**/.claude/
 result
+.claude-reliability/
+.claude/reliability-config.yml
+
+# claude-reliability managed
+.claude/bin/
+.claude/*.local.md
+.claude/*.local.json
+.claude/*.local

Cargo.toml

@@ -3,22 +3,22 @@ name = "hegel"
 version = "0.1.0"
 edition = "2021"
 # if you bump this, also bump ci.yml and hegel-derive/cargo.toml
-rust-version = "1.68"
+rust-version = "1.81"
 description = "Property-based testing SDK for the Hegel test data generator"
 license = "MIT"
 readme = "README.md"
 repository = "https://github.com/antithesishq/hegel-rust"
 
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }
-# float_roundtrip fixes parsing of floats like "0.9999999999999999"
-# See: https://github.com/serde-rs/json/issues/1303
-serde_json = { version = "1.0", features = ["float_roundtrip"] }
 num = "0.4"
 paste = "1.0"
 hegel-derive = { path = "hegel-derive" }
 tempfile = "3.0"
 rand = { version = "0.9", optional = true }
+# Binary protocol support
+ciborium = "0.2"
+crc32fast = "1.4"
 
 [dev-dependencies]
 regex = "1.0"

build.rs

@@ -56,7 +56,7 @@ fn ensure_hegel() -> PathBuf {
         .args([
             "pip",
             "install",
-            "git+ssh://git@github.com/antithesishq/hegel.git",
+            "git+ssh://git@github.com/antithesishq/hegel.git@main",
         ])
         .arg("--python")
         .arg(venv_path.join("bin").join("python"))