ProxyConfigRule

Description says what this rule lets the sandbox reach, so an agent driving the sandbox can be told its capabilities. At most 1024 characters.

EnvVars are plaintext env vars set for every command in the sandbox while this rule is enabled. Use them for tools that refuse to run unless a credential env var is present (e.g. gh needs GH_TOKEN) even though this rule injects the real credential on the wire — set a dummy value here so the command starts. Explicit per-sandbox env_vars win over these, and provider-managed (AWS/GCP) vars win over both.

MatchHeaders restricts a header injection rule to requests carrying every listed header, each written "name: value" with a lowercase name and an exact value. Pair with headers of the same name to swap a placeholder the sandbox sends (e.g. "authorization: Bearer account-b") for a real credential, so one host can serve several accounts. Rules are evaluated in order and the first match wins.

MatchHosts is only accepted for header injection rules.

Provider auth rules use built-in host matching.