diff --git a/docs/ENVIRONMENT.md b/docs/ENVIRONMENT.md
index 11bd220..2340696 100644
--- a/docs/ENVIRONMENT.md
+++ b/docs/ENVIRONMENT.md
@@ -8,7 +8,7 @@ Docker Compose services (in startup order):
 
 | Service | Purpose | Port | Health Check |
 |---------|---------|------|-------------|
-| **anvil** | Local Ethereum fork (Base Sepolia) | 8545 | JSON-RPC response |
+| **anvil** | Local Ethereum fork (Base Sepolia by default; override with `FORK_URL`) | 8545 | JSON-RPC response |
 | **postgres** | Ponder database | 5432 | pg_isready |
 | **bootstrap** | Deploys contracts to anvil | — | One-shot, exits 0 |
 | **ponder** | On-chain indexer + GraphQL API | 42069 | HTTP /ready or GraphQL |
@@ -18,6 +18,46 @@ Docker Compose services (in startup order):
 | **caddy** | Reverse proxy / TLS | 80/443 | — |
 | **otterscan** | Block explorer | 5100 | — |
 
+## Network Contexts
+
+Two network contexts are relevant: the dev-stack Anvil (docker-compose) and the backtesting tools that require Base mainnet.
+
+### Dev stack Anvil (docker-compose)
+
+The `anvil` service in `docker-compose.yml` runs `containers/anvil-entrypoint.sh`, which forks:
+
+```
+${FORK_URL:-https://sepolia.base.org}
+```
+
+**Default: Base Sepolia.** The `bootstrap` service deploys all KRAIKEN protocol contracts (Kraiken, Stake, Optimizer, LiquidityManager) and creates a new KRK/WETH pool using the existing Uniswap V3 Factory already present on the forked network. Addresses are written to `tmp/containers/contracts.env`.
+
+To fork Base mainnet instead (required for red-team / backtesting — see below):
+
+```bash
+FORK_URL=https://mainnet.base.org docker compose up -d
+```
+
+### Backtesting / red-team (`scripts/harb-evaluator/red-team.sh`)
+
+`red-team.sh` boots the docker-compose stack and then calls protocol operations using **Base mainnet** addresses for the Uniswap V3 periphery (V3_FACTORY, SwapRouter02, NonfungiblePositionManager). These addresses are only valid on a mainnet fork.
+
+`red-team.sh` calls `sudo docker compose up -d` internally. The script uses `sudo -E` so that `FORK_URL` is preserved across the sudo boundary:
+
+```bash
+FORK_URL=https://mainnet.base.org bash scripts/harb-evaluator/red-team.sh
+```
+
+### FitnessEvaluator (`onchain/test/FitnessEvaluator.t.sol`)
+
+`FitnessEvaluator.t.sol` does **not** use Anvil. It uses Foundry's native revm backend (`vm.createSelectFork`) to fork Base mainnet in-process — no docker-compose dependency:
+
+```bash
+BASE_RPC_URL=https://mainnet.base.org \
+FITNESS_MANIFEST_DIR=/tmp/manifest \
+forge test --match-contract FitnessEvaluator --match-test testBatchEvaluate -vv
+```
+
 ## Quick Start
 
 ```bash
diff --git a/scripts/harb-evaluator/red-team.sh b/scripts/harb-evaluator/red-team.sh
index 8b51d81..9d8e784 100755
--- a/scripts/harb-evaluator/red-team.sh
+++ b/scripts/harb-evaluator/red-team.sh
@@ -63,11 +63,13 @@ cd "$REPO_ROOT"
 sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches' 2>/dev/null || true
 
 # Tear down completely (volumes too — clean anvil state)
-sudo docker compose down -v >/dev/null 2>&1 || true
+sudo -E docker compose down -v >/dev/null 2>&1 || true
 sleep 3
 
 # Bring up
-sudo docker compose up -d >/dev/null 2>&1 \
+# -E preserves FORK_URL (and other env vars) across the sudo boundary so that
+# anvil-entrypoint.sh honours the caller's FORK_URL override.
+sudo -E docker compose up -d >/dev/null 2>&1 \
   || die "docker compose up -d failed"
 
 # Wait for bootstrap to complete (max 120s)