Migrate from FLOX

lrvx is the new name of FLOX. The engine, the bindings and the on-disk formats are the same; the packages, import names, commands, environment variables and CMake options carry the new name. Existing tapes and run traces read unchanged, and the flox-py and flox-mcp packages remain as deprecated shims, so Python code can move one piece at a time. The old environment variable and CMake option names are not read; the tables below map each one to its new name.

New names

What	FLOX	lrvx
Python package (PyPI)	flox-py	lrvx
Python import	import flox_py	import lrvx
Python CLI	flox	lrvx
MCP server package (PyPI)	flox-mcp	lrvx-mcp
MCP server import / CLI	flox_mcp / flox-mcp	lrvx_mcp / lrvx-mcp
npm package	@flox-foundation/flox	@lrvx/lrvx
Codon package	from flox.strategy import ...	from lrvx.strategy import ...
Embedded QuickJS global	flox	lrvx
C++ namespace / headers	flox::, <flox/...>	lrvx::, <lrvx/...>
CMake package / target	find_package(flox), flox::flox	find_package(lrvx), lrvx::lrvx
C API	libflox_capi, flox_*, Flox*	liblrvx_capi, lrvx_*, Lrvx*
Tape / run / index	.floxlog, .floxrun, index.floxidx	.lrvx, .lrvxrun, index.lrvxidx
Environment variables	FLOX_*	LRVX_*
CMake options	FLOX_*	LRVX_*
Repository	github.com/FLOX-Foundation/flox	github.com/lrvx/lrvx
Documentation	flox-foundation.github.io/flox	docs.lrvx.dev

Install the new packages

pip uninstall flox-py flox-mcp
pip install lrvx            # add lrvx-mcp for the MCP server
npm uninstall @flox-foundation/flox
npm install @lrvx/lrvx

Then replace the imports: import flox_py (or import flox_py as flox) becomes import lrvx, require('@flox-foundation/flox') becomes require('@lrvx/lrvx'), and from flox.<module> import ... in Codon becomes from lrvx.<module> import .... For the MCP server, run lrvx-mcp init to write a client config that launches lrvx-mcp; the server entry is named lrvx, so tools appear under that prefix in the client. An mcpServers.flox entry that launches flox-mcp is replaced rather than kept next to it, and the engine URL and token it carried move over.

Compatibility packages

flox-py 0.10.2 and flox-mcp 0.10.2 are deprecated shims for code that cannot move yet:

• flox-py depends on the matching lrvx release. import flox_py emits one DeprecationWarning and re-exports everything lrvx exports; flox_py.<module> (for example flox_py.cli or flox_py.tape) is the same module object as lrvx.<module>, and flox_py.FloxError is lrvx.LrvxError. The flox command prints a deprecation line to stderr and runs lrvx.
• flox-mcp does the same for lrvx-mcp: import flox_mcp forwards to lrvx_mcp, and the flox-mcp command runs lrvx-mcp.

The shims add nothing of their own and receive no further development. They are built from compat/ in the repository with scripts/build_compat_shims.sh <outdir>.

Environment variables

Every variable reads only its LRVX_* name; the FLOX_* names are not read, so rename them in shell profiles, service units, CI settings and .env files.

FLOX	lrvx	Read by
FLOX_LIVE	LRVX_LIVE	the live project template (lrvx new --template=live)
FLOX_ARCHIVE_CACHE	LRVX_ARCHIVE_CACHE	the exchange archive importers
FLOX_RUNTIME_STATE	LRVX_RUNTIME_STATE	lrvx-mcp runtime tools
FLOX_CONTROL_URL	LRVX_CONTROL_URL	lrvx-mcp control and analytics tools
FLOX_CONTROL_TOKEN	LRVX_CONTROL_TOKEN	lrvx-mcp control and analytics tools
FLOX_HL_SIGNER_SOCKET	LRVX_HL_SIGNER_SOCKET	the Hyperliquid connector's signer client
FLOX_MCP_REQUIRE_DEPS	LRVX_MCP_REQUIRE_DEPS	the lrvx-mcp test suite
FLOX_FUZZ_OPS	LRVX_FUZZ_OPS	the venue differential fuzz test, for a deep run
FLOX_UPDATE_GOLDEN	LRVX_UPDATE_GOLDEN	the venue golden replay test, to rewrite its hashes
FLOX_UPDATE_SESSION_TABLE	LRVX_UPDATE_SESSION_TABLE	the venue session test, to rewrite its golden table
FLOX_BENCH_RT	LRVX_BENCH_RT	batch_delivery_benchmark, to opt in to real-time scheduling
FLOX_LIBCLANG_PATH	LRVX_LIBCLANG_PATH	the C API code generator in tools/codegen
FLOX_LIBCLANG	LRVX_LIBCLANG	scripts/check_gate_reachability.py
FLOX_COMPILE_COMMANDS, FLOX_CMAKE	LRVX_COMPILE_COMMANDS, LRVX_CMAKE	scripts/check_doc_cpp_examples.py
FLOX_PY_BUILD_DIR	LRVX_PY_BUILD_DIR	scripts/gen_pyi_stubs.py
FLOX_CTEST_BUILD_DIR	LRVX_CTEST_BUILD_DIR	scripts/run-with-sanitizer-scan.sh

Default locations carry the new name: the archive cache is ~/.lrvx/archive-cache and the runtime snapshot is /tmp/lrvx-runtime-state.json. Point LRVX_ARCHIVE_CACHE at the old ~/.flox/archive-cache to keep the downloads already cached there.

CMake options

CMake does not recognise the FLOX_* option names. A FLOX_* value passed with -D sets nothing, and CMake lists it under "Manually-specified variables were not used by the project"; one set by a preset, a parent project or an existing build directory's cache is ignored without a warning. Each option keeps its default until it is set under its LRVX_* name.

FLOX	lrvx
FLOX_BUILD_TESTS	LRVX_BUILD_TESTS
FLOX_BUILD_BENCHMARKS	LRVX_BUILD_BENCHMARKS
FLOX_BUILD_DEMO	LRVX_BUILD_DEMO
FLOX_BUILD_TOOLS	LRVX_BUILD_TOOLS
FLOX_BUILD_PYTHON	LRVX_BUILD_PYTHON
FLOX_BUILD_NODE	LRVX_BUILD_NODE
FLOX_BUILD_CAPI	LRVX_BUILD_CAPI
FLOX_BUILD_CODON	LRVX_BUILD_CODON
FLOX_BUILD_QUICKJS	LRVX_BUILD_QUICKJS
FLOX_BUILD_CONNECTORS	LRVX_BUILD_CONNECTORS
FLOX_BUILD_VENUE	LRVX_BUILD_VENUE
FLOX_BUILD_CONNECTOR_INTEGRATION_TESTS	LRVX_BUILD_CONNECTOR_INTEGRATION_TESTS
FLOX_ENABLE_BENCHMARKS, FLOX_ENABLE_TESTS, FLOX_ENABLE_DEMO, FLOX_ENABLE_TOOLS, FLOX_ENABLE_PYTHON, FLOX_ENABLE_CAPI, FLOX_ENABLE_CODON, FLOX_ENABLE_QUICKJS, the older spellings of the FLOX_BUILD_* options	the matching LRVX_BUILD_*
FLOX_ENABLE_BACKTEST	LRVX_ENABLE_BACKTEST
FLOX_ENABLE_LZ4	LRVX_ENABLE_LZ4
FLOX_ENABLE_ONNX	LRVX_ENABLE_ONNX
FLOX_ENABLE_AF_XDP	LRVX_ENABLE_AF_XDP
FLOX_ENABLE_TRACY	LRVX_ENABLE_TRACY
FLOX_ENABLE_CPU_AFFINITY	LRVX_ENABLE_CPU_AFFINITY
FLOX_ENABLE_DEV_SETUP	LRVX_ENABLE_DEV_SETUP
FLOX_ENABLE_POLYMARKET_ORDER_EXECUTOR	LRVX_ENABLE_POLYMARKET_ORDER_EXECUTOR
FLOX_NATIVE	LRVX_NATIVE
FLOX_VENUE_LITE	LRVX_VENUE_LITE
FLOX_VENUE_PERIMETER	LRVX_VENUE_PERIMETER
FLOX_FETCH_GTEST	LRVX_FETCH_GTEST
FLOX_FIX_TLS	LRVX_FIX_TLS
FLOX_RUN_CONNECTOR_INTEGRATION_TESTS	LRVX_RUN_CONNECTOR_INTEGRATION_TESTS
FLOX_CONNECTORS	LRVX_CONNECTORS
FLOX_DEFAULT_EVENTBUS_CAPACITY	LRVX_DEFAULT_EVENTBUS_CAPACITY
FLOX_DEFAULT_EVENTBUS_MAX_CONSUMERS	LRVX_DEFAULT_EVENTBUS_MAX_CONSUMERS
FLOX_NODE_CPU_AFFINITY	LRVX_NODE_CPU_AFFINITY
FLOX_NODE_SANITIZE	LRVX_NODE_SANITIZE

Compile-time defines

Preprocessor switches follow the same rule: a FLOX_* define on the compiler command line or in a config header is not read.

FLOX	lrvx
FLOX_DISABLE_LOGGING	LRVX_DISABLE_LOGGING
FLOX_DEFAULT_ORDER_TRACKER_CAPACITY	LRVX_DEFAULT_ORDER_TRACKER_CAPACITY
FLOX_DEFAULT_CONNECTOR_POOL_CAPACITY	LRVX_DEFAULT_CONNECTOR_POOL_CAPACITY
FLOX_SCALE_CHECKS	LRVX_SCALE_CHECKS
FLOX_FORCE_PORTABLE_INT128	LRVX_FORCE_PORTABLE_INT128
FLOX_FIX_TLS	LRVX_FIX_TLS
FLOX_ENABLE_TRACY	LRVX_ENABLE_TRACY
FLOX_UNIT_TEST	LRVX_UNIT_TEST

Tapes, run traces and indexes

The binary formats are the same under both names and the segment sentinel spells FLOX, so nothing needs converting.

• Directories of .floxlog segments read as they are. Every reader, the validator, the index builders, merge and split, and lrvx tape view accept .floxlog next to .lrvx, and a directory that mixes the two reads as one tape in filename order. New segments are written as .lrvx. See the .lrvx spec.
• A .floxrun trace directory opens like any other: TraceReader takes the directory path whatever its suffix, lrvx tape view accepts .floxrun, and bundle validation reads expected.floxrun/ from bundles packed under the old name. See the .lrvxrun spec.
• A global index written as index.floxidx loads by path with GlobalIndexBuilder::load; rebuilding writes index.lrvxidx. Per-segment indexes live inside the segment files and need nothing.

Renaming existing files to the new extensions is optional.