The :beamlet application config.

config :beamlet,
  data_dir: "/var/lib/beamlet",
  web: [endpoint: MyAppWeb.Endpoint],
  eval: [timeout: 60_000],
  mcp: [request_timeout: 90_000],
  http: [allow: ["homeassistant.local", "192.168.1.0/24"]]

The beamlet checks every key when it starts. A bad value stops the boot with a message naming the key. A change takes a restart.

Times are in milliseconds and sizes in bytes.

Keys

• :data_dir - The directory where the beamlet keeps everything: its databases, the code agents define and the files they keep. Required. It must be an absolute path to a directory that already exists.
• :policies - The policies a token can have besides default, as a keyword list of name to policy. None by default. Beamlet.Policy describes how to write one.
• :eval - Limits on the eval tool. timeout is how long one evaluation may run (30 seconds). max_heap_bytes caps the memory it may use (128 MB), and max_output the output returned to the model (32 KB). Beamlet.MCP.Eval says what happens when each is reached.
• :define - timeout is how long one define or patch may take to compile (30 seconds).
• :mcp - request_timeout is how long the MCP server waits for a tool to answer before replying "Server unavailable" (65 seconds). It must be longer than the eval and define timeouts, so a slow tool reports its own error first.
• :http - allow lists the hosts on private networks that agent code may reach through Host.HTTP, as names, IP addresses or CIDR blocks. A name must be listed as a name: allowing its address or block is not enough. Empty by default, so agent code reaches only the public internet.
• :web - endpoint names the Phoenix endpoint that forwards to Beamlet.Router. Required. prefix is a path to serve the routes agents mount under, such as "/app", and cannot be under /beamlet. Empty by default, which serves them at the root.