diff --git a/lib/contracts/abi.ts b/lib/contracts/abi.ts
new file mode 100644
index 00000000..5acfc481
--- /dev/null
+++ b/lib/contracts/abi.ts
@@ -0,0 +1,97 @@
+/**
+ * StoryFactory contract ABIs — event signatures and write functions.
+ *
+ * Source: proposal §4.1 (events), §4.3 (StoryFactory interface).
+ * Contract address: see constants.ts (TBD until deployment).
+ */
+
+// ---------------------------------------------------------------------------
+// Events
+// ---------------------------------------------------------------------------
+
+export const plotChainedEvent = {
+  type: "event",
+  name: "PlotChained",
+  inputs: [
+    { name: "storylineId", type: "uint256", indexed: true },
+    { name: "plotIndex", type: "uint256", indexed: true },
+    { name: "writer", type: "address", indexed: true },
+    { name: "contentCID", type: "string", indexed: false },
+    { name: "contentHash", type: "bytes32", indexed: false },
+  ],
+} as const;
+
+export const storylineCreatedEvent = {
+  type: "event",
+  name: "StorylineCreated",
+  inputs: [
+    { name: "storylineId", type: "uint256", indexed: true },
+    { name: "writer", type: "address", indexed: true },
+    { name: "tokenAddress", type: "address", indexed: false },
+    { name: "title", type: "string", indexed: false },
+    { name: "hasDeadline", type: "bool", indexed: false },
+  ],
+} as const;
+
+export const donationEvent = {
+  type: "event",
+  name: "Donation",
+  inputs: [
+    { name: "storylineId", type: "uint256", indexed: true },
+    { name: "donor", type: "address", indexed: true },
+    { name: "amount", type: "uint256", indexed: false },
+  ],
+} as const;
+
+// ---------------------------------------------------------------------------
+// Functions
+// ---------------------------------------------------------------------------
+
+export const createStorylineFunction = {
+  type: "function",
+  name: "createStoryline",
+  stateMutability: "nonpayable",
+  inputs: [
+    { name: "title", type: "string" },
+    { name: "openingCID", type: "string" },
+    { name: "openingHash", type: "bytes32" },
+    { name: "hasDeadline", type: "bool" },
+  ],
+  outputs: [{ name: "storylineId", type: "uint256" }],
+} as const;
+
+export const chainPlotFunction = {
+  type: "function",
+  name: "chainPlot",
+  stateMutability: "nonpayable",
+  inputs: [
+    { name: "storylineId", type: "uint256" },
+    { name: "contentCID", type: "string" },
+    { name: "contentHash", type: "bytes32" },
+  ],
+  outputs: [],
+} as const;
+
+export const donateFunction = {
+  type: "function",
+  name: "donate",
+  stateMutability: "nonpayable",
+  inputs: [
+    { name: "storylineId", type: "uint256" },
+    { name: "amount", type: "uint256" },
+  ],
+  outputs: [],
+} as const;
+
+// ---------------------------------------------------------------------------
+// Combined ABI (for viem contract instances)
+// ---------------------------------------------------------------------------
+
+export const storyFactoryAbi = [
+  plotChainedEvent,
+  storylineCreatedEvent,
+  donationEvent,
+  createStorylineFunction,
+  chainPlotFunction,
+  donateFunction,
+] as const;
diff --git a/lib/contracts/constants.ts b/lib/contracts/constants.ts
new file mode 100644
index 00000000..d95bdd14
--- /dev/null
+++ b/lib/contracts/constants.ts
@@ -0,0 +1,57 @@
+/**
+ * Contract addresses and chain configuration for PlotLink on Base.
+ *
+ * Source: proposal §12 (External Dependencies).
+ *
+ * PlotLink-owned contracts (StoryFactory, ZapPlotLinkMCV2, $PLOT) use
+ * placeholder zero addresses until deployed to Base mainnet.
+ */
+
+// ---------------------------------------------------------------------------
+// Chain
+// ---------------------------------------------------------------------------
+
+export const BASE_CHAIN_ID = 8453;
+
+// ---------------------------------------------------------------------------
+// PlotLink contracts (TBD — replace after deployment)
+// ---------------------------------------------------------------------------
+
+/** StoryFactory — storyline + plot management */
+export const STORY_FACTORY = "0x0000000000000000000000000000000000000000" as const;
+
+/** ZapPlotLinkMCV2 — one-click buy (ETH/USDC/HUNT -> storyline token) */
+export const ZAP_PLOTLINK = "0x0000000000000000000000000000000000000000" as const;
+
+/** $PLOT protocol token (ERC-20, issued via Mint Club backed by $HUNT) */
+export const PLOT_TOKEN = "0x0000000000000000000000000000000000000000" as const;
+
+// ---------------------------------------------------------------------------
+// Mint Club V2 (deployed on Base — immutable third-party contracts)
+// ---------------------------------------------------------------------------
+
+/** MCV2_Bond — bonding curve trading, token creation, royalty distribution */
+export const MCV2_BOND = "0xc5a076cad94176c2996B32d8466Be1cE757FAa27" as const;
+
+/** MCV2_BondPeriphery — helper for multi-step bond operations */
+export const MCV2_BOND_PERIPHERY = "0x492C412369Db76C9cdD9939e6C521579301473a3" as const;
+
+// ---------------------------------------------------------------------------
+// Uniswap V4 (Base)
+// ---------------------------------------------------------------------------
+
+/** Universal Router — swap execution */
+export const UNISWAP_V4_ROUTER = "0x6fF5693b99212Da76ad316178A184AB56D299b43" as const;
+
+/** Quoter — price estimation for frontend quotes */
+export const UNISWAP_V4_QUOTER = "0x0d5e0F971ED27FBfF6c2837bf31316121532048D" as const;
+
+/** Permit2 — gasless token approvals */
+export const PERMIT2 = "0x000000000022D473030F116dDEE9F6B43aC78BA3" as const;
+
+// ---------------------------------------------------------------------------
+// ERC-8004 Agent Identity (Base)
+// ---------------------------------------------------------------------------
+
+/** Agent Registry — agent writer identity NFTs and reputation */
+export const ERC8004_REGISTRY = "0x8004A169FB4a3325136EB29fA0ceB6D2e539a432" as const;