docs(book): replace manual placeholders with environment variables

.env.example

@@ -3,6 +3,37 @@ AVALANCHE_FUJI_RPC_URL=https://your-avalanche-fuji-rpc-url
 POLYGON_AMOY_RPC_URL=https://your-polygon-amoy-rpc-url
 BASE_SEPOLIA_RPC_URL=https://your-base-sepolia-rpc-url
 
+# Your account address. Fill in with: cast wallet address --account myAccount
+MY_EOA=
+
+# Network constants used by the book (book/src). Fill these in from https://docs.chain.link/ccip/directory
+# (router, chain selector, LINK, CCIP-BnM, RMN/ARM proxy, registry module owner, token admin registry).
+# Only fill the chains you plan to run.
+# Ethereum Sepolia
+SEPOLIA_CHAIN_SELECTOR=
+SEPOLIA_ROUTER=
+SEPOLIA_LINK=
+SEPOLIA_CCIP_BNM=
+SEPOLIA_ARM_PROXY=
+SEPOLIA_REGISTRY_MODULE_OWNER_CUSTOM=
+SEPOLIA_TOKEN_ADMIN_REGISTRY=
+# Polygon Amoy
+AMOY_CHAIN_SELECTOR=
+AMOY_ROUTER=
+AMOY_LINK=
+AMOY_CCIP_BNM=
+AMOY_ARM_PROXY=
+AMOY_REGISTRY_MODULE_OWNER_CUSTOM=
+AMOY_TOKEN_ADMIN_REGISTRY=
+# Avalanche Fuji (Legacy examples)
+FUJI_CHAIN_SELECTOR=
+FUJI_ROUTER=
+FUJI_LINK=
+FUJI_CCIP_BNM=
+
+# Optional. The SDK examples (sdk-examples) read USER_KEY (or PRIVATE_KEY) for non-dry-run sends.
+# USER_KEY=
+
 # Optional. Fork tests (test/fork, FOUNDRY_PROFILE=fork) are pinned to the blocks in test/fork/utils/CCTForkTest.sol.
 # Set these to run against a different block, for example a recent one to check whether the live lane has drifted.
 # ETHEREUM_SEPOLIA_FORK_BLOCK=<block number>

book/src/examples/example01-token-transfer-faster-than-finality.md

@@ -26,6 +26,18 @@ Script path: `script/examples/Example01.s.sol`
 > This chapter assumes `--account myAccount`.
 
 
+## Chapter Parameters
+
+Set the parameters for this chapter. The defaults work as they are; change a value only if you want something different.
+
+```bash
+export RECEIVER=$MY_EOA          # destination EOA
+export AMOUNT=1000000000000000000  # 1 token (18 decimals)
+export GAS_LIMIT=0               # token-only transfer to an EOA
+export BLOCK_CONFIRMATIONS=1     # Fast Transfers depth, must be > 0
+export FEE_TOKEN=0x0000000000000000000000000000000000000000  # native fee; use $SEPOLIA_LINK to pay in LINK
+```
+
 ## Step 1: Get 1 CCIP-BnM Token
 
 Use the faucet script on the source chain:
@@ -36,17 +48,18 @@ forge script script/Faucet.s.sol:Faucet \
   --account myAccount \
   --broadcast \
   --sig "run(address)" \
-  <CCIP_BNM_SOURCE_TOKEN_ADDRESS>
+  $SEPOLIA_CCIP_BNM
 ```
 
 ## Step 2: (Optional) Check Executor Allowed Finality
 
 Before choosing a Fast Transfers depth in `ExtraArgsV3`, you can read what finality modes the **Executor** allows. The on-chain API is **`getAllowedFinalityConfig() → bytes4`**, encoded with **`FinalityCodec`** (same family of values as `requestedFinalityConfig` in your message’s ExtraArgs).
 
-From a shell (replace RPC and address):
+From a shell. The executor address is printed as `[GATE] Executor:` by the finality-gates check further down this step; run that first, then export it:
 
 ```bash
-cast call <EXECUTOR_ADDRESS> "getAllowedFinalityConfig()(bytes4)" --rpc-url ethereumSepolia
+export EXECUTOR_ADDRESS=0x...
+cast call $EXECUTOR_ADDRESS "getAllowedFinalityConfig()(bytes4)" --rpc-url ethereumSepolia
 ```
 
 Why this matters:
@@ -59,7 +72,7 @@ Check the source pool, executor, and CCV finality settings before sending:
 forge script script/examples/Example06.s.sol:Example06CheckFinalityGates \
   --rpc-url ethereumSepolia \
   --sig "run(address,uint64,address,uint16)" \
-  <SOURCE_ROUTER> <DESTINATION_CHAIN_SELECTOR> <CCIP_BNM_SOURCE_TOKEN_ADDRESS> <BLOCK_CONFIRMATIONS_GT_ZERO>
+  $SEPOLIA_ROUTER $AMOY_CHAIN_SELECTOR $SEPOLIA_CCIP_BNM $BLOCK_CONFIRMATIONS
 ```
 
 A quote alone does not prove `ccipSend` will succeed with a non-`IPoolV2` pool.
@@ -74,22 +87,22 @@ forge script script/examples/Example01.s.sol:Example01 \
   --account myAccount \
   --broadcast \
   --sig "run(address,uint64,address,address,uint256,uint32,uint16,address)" \
-  <SOURCE_ROUTER> \
-  <DESTINATION_CHAIN_SELECTOR> \
-  <RECEIVER_ON_DESTINATION_CHAIN> \
-  <CCIP_BNM_SOURCE_TOKEN_ADDRESS> \
-  <AMOUNT> \
-  <GAS_LIMIT> \
-  <BLOCK_CONFIRMATIONS_GT_ZERO> \
-  <FEE_TOKEN_ADDRESS>
+  $SEPOLIA_ROUTER \
+  $AMOY_CHAIN_SELECTOR \
+  $RECEIVER \
+  $SEPOLIA_CCIP_BNM \
+  $AMOUNT \
+  $GAS_LIMIT \
+  $BLOCK_CONFIRMATIONS \
+  $FEE_TOKEN
 ```
 
 Parameter notes:
 
-- `<AMOUNT>`: token amount in token decimals (for 18 decimals, `1e18` is 1 token).
-- `<GAS_LIMIT>`: set to `0` for token-only transfer to an EOA receiver.
-- `<BLOCK_CONFIRMATIONS_GT_ZERO>`: must be `> 0` and meet the source pool and executor minimums from Step 2.
-- `<FEE_TOKEN_ADDRESS>`: Pass the LINK token address on the source chain here. If you want to pay for CCIP fees in native coin instead, pass `0x0000000000000000000000000000000000000000`
+- `$AMOUNT`: token amount in token decimals (for 18 decimals, `1e18` is 1 token).
+- `$GAS_LIMIT`: set to `0` for token-only transfer to an EOA receiver.
+- `$BLOCK_CONFIRMATIONS`: must be `> 0` and meet the source pool and executor minimums from Step 2.
+- `$FEE_TOKEN`: native coin by default (`0x0000000000000000000000000000000000000000`). To pay CCIP fees in LINK instead, run `export FEE_TOKEN=$SEPOLIA_LINK`.
 
 ## Verify Result
 

book/src/examples/example02-hello-world-to-basic-message-receiver.md

@@ -29,6 +29,17 @@ Scripts used:
 >
 > This chapter assumes `--account myAccount`.
 
+## Chapter Parameters
+
+Set the parameters for this chapter. The defaults work as they are; change a value only if you want something different.
+
+```bash
+export GAS_LIMIT=200000          # the receiver callback needs gas
+export BLOCK_CONFIRMATIONS=1     # Fast Transfers depth, must be > 0
+export MIN_BLOCK_DEPTH=1         # receiver minimum, must be <= BLOCK_CONFIRMATIONS
+export FEE_TOKEN=0x0000000000000000000000000000000000000000  # native fee; use $SEPOLIA_LINK to pay in LINK
+```
+
 ## Receiver Contract Context
 
 ### Pre-v2.0
@@ -99,10 +110,14 @@ forge script script/examples/Example02.s.sol:DeployBasicMessageReceiverWithCCVs
   --account myAccount \
   --broadcast \
   --sig "run(address)" \
-  <DESTINATION_ROUTER>
+  $AMOY_ROUTER
 ```
 
-Save the deployed address as `<BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS>`.
+Copy the deployed address from the `[RESULT]` log and export it:
+
+```bash
+export BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS=0x...
+```
 
 By default, this receiver starts with `minBlockDepth = 0` (default finality only) for all source chains.
 
@@ -116,12 +131,12 @@ forge script script/examples/Example02.s.sol:SetBasicMessageReceiverWithCCVsMinB
   --account myAccount \
   --broadcast \
   --sig "run(address,uint64,uint16)" \
-  <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> \
-  <SOURCE_CHAIN_SELECTOR> \
-  <MIN_BLOCK_DEPTH>
+  $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS \
+  $SEPOLIA_CHAIN_SELECTOR \
+  $MIN_BLOCK_DEPTH
 ```
 
-For this chapter, use `<MIN_BLOCK_DEPTH> = 1`.
+This chapter uses `MIN_BLOCK_DEPTH=1` (set in Chapter Parameters).
 
 - `0` means deafault finality-only behavior.
 - `> 0` enables Fast Transfers with that minimum depth.
@@ -136,23 +151,23 @@ forge script script/examples/Example02.s.sol:Example02 \
   --account myAccount \
   --broadcast \
   --sig "run(address,uint64,address,string,uint32,uint16,address)" \
-  <SOURCE_ROUTER> \
-  <DESTINATION_CHAIN_SELECTOR> \
-  <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> \
+  $SEPOLIA_ROUTER \
+  $AMOY_CHAIN_SELECTOR \
+  $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS \
   "Hello, World" \
-  <GAS_LIMIT> \
-  <BLOCK_CONFIRMATIONS_GT_ZERO> \
-  <FEE_TOKEN_ADDRESS>
+  $GAS_LIMIT \
+  $BLOCK_CONFIRMATIONS \
+  $FEE_TOKEN
 ```
 
 Parameter notes:
 
-- `<GAS_LIMIT>` must be `> 0` because the destination receiver callback needs gas.
-- `<BLOCK_CONFIRMATIONS_GT_ZERO>` must be `> 0` for Fast Transfers.
-- `<BLOCK_CONFIRMATIONS_GT_ZERO>` should be greater than or equal to `<MIN_BLOCK_DEPTH>`.
+- `$GAS_LIMIT` must be `> 0` because the destination receiver callback needs gas.
+- `$BLOCK_CONFIRMATIONS` must be `> 0` for Fast Transfers.
+- `$BLOCK_CONFIRMATIONS` should be greater than or equal to `$MIN_BLOCK_DEPTH`.
 - Executor may enforce a minimum block confirmations value and revert if too low.
 - If requested confirmations exceed chain finality, default finality is used.
-- `<FEE_TOKEN_ADDRESS>`: Pass the LINK token address on the source chain here. If you want to pay for CCIP fees in native coin instead, pass `0x0000000000000000000000000000000000000000`
+- `$FEE_TOKEN`: native coin by default (`0x0000000000000000000000000000000000000000`). To pay CCIP fees in LINK instead, run `export FEE_TOKEN=$SEPOLIA_LINK`.
 
 ## Verify Result
 
@@ -165,5 +180,5 @@ Use that ID in the CCIP Explorer:
 You can inspect receiver state on destination chain:
 
 ```bash
-cast call <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> "latestMessage()(bytes)" --rpc-url polygonAmoy
+cast call $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS "latestMessage()(bytes)" --rpc-url polygonAmoy
 ```

book/src/examples/example03-programmable-token-transfer-data-and-token.md

@@ -21,6 +21,18 @@ This chapter uses Fast Transfers (`blockConfirmations > 0`), so destination rece
 - Deploy `BasicMessageReceiverWithCCVs` before running this chapter.
 - For default-finality programmable token transfer (`blockConfirmations = 0`), use Example04.
 
+## Chapter Parameters
+
+Set the parameters for this chapter. The defaults work as they are; change a value only if you want something different.
+
+```bash
+export AMOUNT=1000000000000000000  # 1 token (18 decimals)
+export GAS_LIMIT=200000          # the receiver callback handles data
+export BLOCK_CONFIRMATIONS=1     # Fast Transfers depth, must be > 0
+export MIN_BLOCK_DEPTH=1         # receiver minimum, must be <= BLOCK_CONFIRMATIONS
+export FEE_TOKEN=0x0000000000000000000000000000000000000000  # native fee; use $SEPOLIA_LINK to pay in LINK
+```
+
 ## Before You Start
 
 > **Important: Keystore first**
@@ -46,7 +58,7 @@ This chapter uses Fast Transfers (`blockConfirmations > 0`), so destination rece
 >   --account myAccount \
 >   --broadcast \
 >   --sig "run(address)" \
->   <DESTINATION_ROUTER>
+>   $AMOY_ROUTER
 > ```
 >
 > Then configure min block depth for your source chain:
@@ -57,16 +69,20 @@ This chapter uses Fast Transfers (`blockConfirmations > 0`), so destination rece
 >   --account myAccount \
 >   --broadcast \
 >   --sig "run(address,uint64,uint16)" \
->   <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> \
->   <SOURCE_CHAIN_SELECTOR> \
->   <MIN_BLOCK_DEPTH>
+>   $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS \
+>   $SEPOLIA_CHAIN_SELECTOR \
+>   $MIN_BLOCK_DEPTH
 > ```
 >
-> For this Fast Transfers example, use `<MIN_BLOCK_DEPTH> > 0` and check the source pool minimum too.
+> For this Fast Transfers example, `MIN_BLOCK_DEPTH` must be `> 0` (the default is `1`). Check the source pool minimum too.
+>
+> The script argument accepts `$MIN_BLOCK_DEPTH` (a `uint16` passed to `BasicMessageReceiverWithCCVs.setMinBlockDepth`). On-chain, the receiver does not return that integer directly to CCIP: `getCCVsAndFinalityConfig` sets `allowedFinalityConfig` to `FinalityCodec._encodeBlockDepth(minBlockDepth)` — the same `bytes4` finality encoding CCIP 2.0 uses elsewhere for allowed finality (depth `0` means wait for full/default finality).
 >
-> The script argument accepts `<MIN_BLOCK_DEPTH>` (a `uint16` passed to `BasicMessageReceiverWithCCVs.setMinBlockDepth`). On-chain, the receiver does not return that integer directly to CCIP: `getCCVsAndFinalityConfig` sets `allowedFinalityConfig` to `FinalityCodec._encodeBlockDepth(minBlockDepth)` — the same `bytes4` finality encoding CCIP 2.0 uses elsewhere for allowed finality (depth `0` means wait for full/default finality).
+> Copy the receiver address from the `[RESULT]` log and export it for Step 2 below:
 >
-> Save the receiver address from the `[RESULT]` log and use it in Step 2 below.
+> ```bash
+> export BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS=0x...
+> ```
 
 ## Step 1: Get 1 CCIP-BnM Token on Sepolia
 
@@ -78,7 +94,7 @@ forge script script/Faucet.s.sol:Faucet \
   --account myAccount \
   --broadcast \
   --sig "run(address)" \
-  <CCIP_BNM_SOURCE_TOKEN_ADDRESS>
+  $SEPOLIA_CCIP_BNM
 ```
 
 ## Step 2: Send Hello World + CCIP-BnM
@@ -89,25 +105,25 @@ forge script script/examples/Example03.s.sol:Example03 \
   --account myAccount \
   --broadcast \
   --sig "run(address,uint64,address,string,address,uint256,uint32,uint16,address)" \
-  <SOURCE_ROUTER> \
-  <DESTINATION_CHAIN_SELECTOR> \
-  <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> \
+  $SEPOLIA_ROUTER \
+  $AMOY_CHAIN_SELECTOR \
+  $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS \
   "Hello, World" \
-  <CCIP_BNM_SOURCE_TOKEN_ADDRESS> \
-  <AMOUNT> \
-  <GAS_LIMIT> \
-  <BLOCK_CONFIRMATIONS_GT_ZERO> \
-  <FEE_TOKEN_ADDRESS>
+  $SEPOLIA_CCIP_BNM \
+  $AMOUNT \
+  $GAS_LIMIT \
+  $BLOCK_CONFIRMATIONS \
+  $FEE_TOKEN
 ```
 
 Parameter notes:
 
-- `<AMOUNT>` uses token decimals (`1e18` is 1 token for 18-decimal tokens).
-- `<GAS_LIMIT>` must be `> 0` because the receiver contract callback handles data.
-- `<BLOCK_CONFIRMATIONS_GT_ZERO>` must meet the source pool and receiver minimums.
+- `$AMOUNT` uses token decimals (`1e18` is 1 token for 18-decimal tokens).
+- `$GAS_LIMIT` must be `> 0` because the receiver contract callback handles data.
+- `$BLOCK_CONFIRMATIONS` must meet the source pool and receiver minimums.
 - Executor may enforce a minimum block confirmation value and revert if too low.
 - If requested confirmations exceed chain finality, default finality is used.
-- `<FEE_TOKEN_ADDRESS>`: Pass the LINK token address on the source chain here. If you want to pay for CCIP fees in native coin instead, pass `0x0000000000000000000000000000000000000000`
+- `$FEE_TOKEN`: native coin by default (`0x0000000000000000000000000000000000000000`). To pay CCIP fees in LINK instead, run `export FEE_TOKEN=$SEPOLIA_LINK`.
 
 ## Verify Result
 
@@ -118,7 +134,7 @@ Parameter notes:
 Optional receiver checks on Amoy:
 
 ```bash
-cast call <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> "latestMessage()(bytes)" --rpc-url polygonAmoy
-cast call <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> "latestSender()(address)" --rpc-url polygonAmoy
-cast call <BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS> "latestSourceChainSelector()(uint64)" --rpc-url polygonAmoy
+cast call $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS "latestMessage()(bytes)" --rpc-url polygonAmoy
+cast call $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS "latestSender()(address)" --rpc-url polygonAmoy
+cast call $BASIC_MESSAGE_RECEIVER_WITH_CCVS_ADDRESS "latestSourceChainSelector()(uint64)" --rpc-url polygonAmoy
 ```