Configuration

Everything is set through environment variables on docker run. The bridge reads its settings once at startup in src/config.ts, and any invalid value stops it with exit code 2 instead of falling back to a default. Troubleshooting lists each message.

Bridge

These apply to the default bridge mode.

Variable	Default	Valid values	Description
REA_BRIDGE_TOKEN	required	32 characters or more	Bearer token every MCP request must send. Never passed to REA.
REA_BRIDGE_PORT	8080	1 to 65535	Listen port inside the container.
REA_BRIDGE_HOST	0.0.0.0	an address	Listen address inside the container.
REA_BRIDGE_PATH	/mcp	starts with /	MCP endpoint path.
REA_BRIDGE_ALLOWED_HOSTS	localhost,127.0.0.1,[::1]	comma-separated host names, or *	Accepted Host header names, port ignored (DNS rebinding guard). * disables the check.
REA_BRIDGE_MAX_SESSIONS	4	1 to 64	Concurrent MCP sessions, each with its own REA process.
REA_BRIDGE_IDLE_TIMEOUT_SECONDS	1800	1 to 86400	Idle sessions get closed and their REA process stopped.
REA_BRIDGE_MAX_BODY_BYTES	4194304	1024 to 67108864	Largest accepted request body.
REA_BRIDGE_LOG_LEVEL	info	debug, info, warn, error	Log level. Logs are JSON lines on stdout. The opt-in tool installer uses the same level.
REA_BRIDGE_WORKDIR	/work	a directory	Working directory of each REA process. The image sets it to /work.

Generate a token with:

openssl rand -hex 32

Host names in REA_BRIDGE_ALLOWED_HOSTS are compared in lowercase. Write an IPv6 address in brackets, like [::1]. When you put a reverse proxy in front, add the host name clients use.

Two more variables exist for the bridge’s own tests: REA_BRIDGE_REA_COMMAND (default rea) and REA_BRIDGE_REA_ARGS (a JSON array of strings, default ["mcp"]) replace the command each session runs. Leave them unset in production.

Every variable whose name starts with REA_BRIDGE_ is removed from the environment REA runs with, so the token never reaches REA or the programs it starts.

Opt-in tools

These apply to every mode. See Opt-in tools.

Variable	Default	Description
REA_INSTALL	unset	Comma-separated opt-in tools to install on start. Today: ghidra.
REA_TOOLS_DIR	/opt/rea-tools	Where opt-in tools are installed. Mount a volume here.
GHIDRA_INSTALL_DIR	unset	Your own Ghidra. When set, REA_INSTALL=ghidra skips the download and REA uses this one.

REA’s own variables

Everything else passes straight through to REA. Useful ones:

Variable	Use
REA_JADX_HEAP_MIB	More heap for JADX on big APKs.
REA_JADX_OPERATION_TIMEOUT_MS	A longer JADX timeout on big APKs.
REA_LOG_LEVEL	REA’s own log level. In bridge mode REA’s stderr lines show up in the bridge log.
REA_MCP_MAX_RESPONSE_BYTES	REA’s cap on one MCP response.
REA_IDA_MCP_CONFIG	Bring your own IDA.
REA_JEB_MCP_URL	Bring your own JEB.

REA’s documentation has the full list. The image presets JAVA_HOME, REA_JADX_MCP_JAR, REA_APKTOOL_COMMAND and REA_ADB_PATH (see preset paths). Override them only if you mount a replacement tool.