diff --git a/packages/sdk-core/src/contracts/sysio/chains/Actions.ts b/packages/sdk-core/src/contracts/sysio/chains/Actions.ts
index 102a015..5f52ea3 100644
--- a/packages/sdk-core/src/contracts/sysio/chains/Actions.ts
+++ b/packages/sdk-core/src/contracts/sysio/chains/Actions.ts
@@ -6,9 +6,11 @@ import { DEFAULT_CHAINS_CONTRACT, MAX_EXTERNAL_CHAIN_ID } from "./Constants.js"
 import { descriptor } from "./Descriptor.js"
 import { chainSlugData } from "./Slug.js"
 import type {
+  ChainOutpostAddresses,
   ChainRegistration,
   CreateActivateChainActionOptions,
-  CreateRegisterChainActionOptions
+  CreateRegisterChainActionOptions,
+  CreateSetOutpostActionOptions
 } from "./Types.js"
 
 function assertExternalChainId(value: number): number {
@@ -19,6 +21,23 @@ function assertExternalChainId(value: number): number {
   return value
 }
 
+/**
+ * Fills the generated `outpost_addrs` struct, defaulting every omitted role to
+ * an empty string. The protocol treats empty as "not configured yet" and both
+ * operator daemons skip such a chain, so an omitted field is a deferral rather
+ * than a silent wrong value.
+ */
+function outpostAddressData(
+  outpost: Partial<ChainOutpostAddresses> | undefined
+): SysioContracts.SysioChainsOutpostAddrsType {
+  return {
+    opp_addr: outpost?.oppAddress ?? "",
+    opp_inbound_addr: outpost?.oppInboundAddress ?? "",
+    operator_registry_addr: outpost?.operatorRegistryAddress ?? "",
+    source_deposit_addr: outpost?.sourceDepositAddress ?? ""
+  }
+}
+
 /** Creates generated action data for `sysio.chains::regchain`. */
 export function createRegisterChainActionData(
   registration: ChainRegistration
@@ -28,7 +47,8 @@ export function createRegisterChainActionData(
     code: chainSlugData(registration.code),
     external_chain_id: assertExternalChainId(registration.externalChainId),
     name: registration.name,
-    description: registration.description
+    description: registration.description,
+    outpost: outpostAddressData(registration.outpost)
   }
 }
 
@@ -44,6 +64,26 @@ export function createRegisterChainAction(
   })
 }
 
+/** Creates generated action data for `sysio.chains::setoutpost`. */
+export function createSetOutpostActionData(
+  code: CreateSetOutpostActionOptions["code"],
+  outpost: CreateSetOutpostActionOptions["outpost"]
+): SysioContracts.SysioChainsSetoutpostAction {
+  return { code: chainSlugData(code), outpost: outpostAddressData(outpost) }
+}
+
+/** Creates an unsigned privileged `sysio.chains::setoutpost` action. */
+export function createSetOutpostAction(
+  options: CreateSetOutpostActionOptions
+): Action {
+  return buildContractAction({
+    contract: options.contract || DEFAULT_CHAINS_CONTRACT,
+    descriptor: descriptor.actions.setoutpost,
+    authorization: options.authorization,
+    data: createSetOutpostActionData(options.code, options.outpost)
+  })
+}
+
 /** Creates generated action data for `sysio.chains::activchain`. */
 export function createActivateChainActionData(
   code: CreateActivateChainActionOptions["code"]
diff --git a/packages/sdk-core/src/contracts/sysio/chains/Client.ts b/packages/sdk-core/src/contracts/sysio/chains/Client.ts
index 4c6f205..167f563 100644
--- a/packages/sdk-core/src/contracts/sysio/chains/Client.ts
+++ b/packages/sdk-core/src/contracts/sysio/chains/Client.ts
@@ -66,6 +66,12 @@ export function normalizeChainRow(
     active: row.active,
     registeredAtMs: BigInt(row.registered_at_ms.toString()),
     activatedAtMs: BigInt(row.activated_at_ms.toString()),
+    outpost: {
+      oppAddress: row.outpost?.opp_addr ?? "",
+      oppInboundAddress: row.outpost?.opp_inbound_addr ?? "",
+      operatorRegistryAddress: row.outpost?.operator_registry_addr ?? "",
+      sourceDepositAddress: row.outpost?.source_deposit_addr ?? ""
+    },
     raw: row
   }
 }
diff --git a/packages/sdk-core/src/contracts/sysio/chains/Descriptor.ts b/packages/sdk-core/src/contracts/sysio/chains/Descriptor.ts
index 5a9b464..9b9c6eb 100644
--- a/packages/sdk-core/src/contracts/sysio/chains/Descriptor.ts
+++ b/packages/sdk-core/src/contracts/sysio/chains/Descriptor.ts
@@ -2,7 +2,11 @@ import type { ContractDescriptor } from "../../Contract.js"
 import type * as SysioContracts from "../../../types/SysioContractTypes.js"
 
 import { DEFAULT_CHAINS_CONTRACT } from "./Constants.js"
-import { ChainsActivateChain, ChainsRegisterChain } from "./Structs.js"
+import {
+  ChainsActivateChain,
+  ChainsRegisterChain,
+  ChainsSetOutpost
+} from "./Structs.js"
 
 /** Generated `sysio.chains` action data keyed by ABI action name. */
 export interface SysioChainsActionData {
@@ -10,6 +14,8 @@ export interface SysioChainsActionData {
   regchain: SysioContracts.SysioChainsRegchainAction
   /** `sysio.chains::activchain` action data. */
   activchain: SysioContracts.SysioChainsActivchainAction
+  /** `sysio.chains::setoutpost` action data. */
+  setoutpost: SysioContracts.SysioChainsSetoutpostAction
 }
 
 /** Generated `sysio.chains` table rows keyed by ABI table name. */
@@ -32,6 +38,10 @@ export const descriptor: ContractDescriptor<
     activchain: {
       name: "activchain",
       serialize: data => ChainsActivateChain.from(data)
+    },
+    setoutpost: {
+      name: "setoutpost",
+      serialize: data => ChainsSetOutpost.from(data)
     }
   },
   tables: {
diff --git a/packages/sdk-core/src/contracts/sysio/chains/Structs.ts b/packages/sdk-core/src/contracts/sysio/chains/Structs.ts
index 343dd5b..ab5b6eb 100644
--- a/packages/sdk-core/src/contracts/sysio/chains/Structs.ts
+++ b/packages/sdk-core/src/contracts/sysio/chains/Structs.ts
@@ -8,6 +8,29 @@ export class ChainsSlugName extends Struct {
   @Struct.field("uint64") declare value: UInt64
 }
 
+/**
+ * Runtime serializer for the nested `outpost_addrs` struct.
+ *
+ * An EVM outpost names a distinct contract per role; an SVM outpost is one
+ * program named by `opp_addr`, and `sysio.chains` requires the role fields to be
+ * empty for it. A chain may also be registered before its remote contracts
+ * exist, leaving every field empty until `setoutpost` fills them in.
+ */
+@Struct.type("outpost_addrs")
+export class ChainsOutpostAddrs extends Struct {
+  /** EVM: the OPP contract. SVM: the outpost program id. */
+  @Struct.field("string") declare opp_addr: string
+
+  /** EVM: the OPPInbound contract. Empty for SVM. */
+  @Struct.field("string") declare opp_inbound_addr: string
+
+  /** EVM: the OperatorRegistry contract. Empty for SVM. */
+  @Struct.field("string") declare operator_registry_addr: string
+
+  /** EVM: the source swap-deposit contract. Empty for SVM. */
+  @Struct.field("string") declare source_deposit_addr: string
+}
+
 /** Runtime serializer for `sysio.chains::regchain`. */
 @Struct.type("regchain")
 export class ChainsRegisterChain extends Struct {
@@ -25,6 +48,19 @@ export class ChainsRegisterChain extends Struct {
 
   /** Human-readable chain description. */
   @Struct.field("string") declare description: string
+
+  /** Remote outpost contract identities for this chain. */
+  @Struct.field(ChainsOutpostAddrs) declare outpost: ChainsOutpostAddrs
+}
+
+/** Runtime serializer for `sysio.chains::setoutpost`. */
+@Struct.type("setoutpost")
+export class ChainsSetOutpost extends Struct {
+  /** Stable protocol chain code whose deployment is being replaced. */
+  @Struct.field(ChainsSlugName) declare code: ChainsSlugName
+
+  /** Replacement remote contract identities. The whole set is replaced. */
+  @Struct.field(ChainsOutpostAddrs) declare outpost: ChainsOutpostAddrs
 }
 
 /** Runtime serializer for `sysio.chains::activchain`. */
diff --git a/packages/sdk-core/src/contracts/sysio/chains/Types.ts b/packages/sdk-core/src/contracts/sysio/chains/Types.ts
index 199e7dc..6b29dc2 100644
--- a/packages/sdk-core/src/contracts/sysio/chains/Types.ts
+++ b/packages/sdk-core/src/contracts/sysio/chains/Types.ts
@@ -14,6 +14,25 @@ export interface ChainsClientOptions {
   contract?: NameType
 }
 
+/**
+ * Remote outpost contract identities for one chain.
+ *
+ * An EVM outpost deploys a distinct contract per role. An SVM outpost is a
+ * single program named by `oppAddress`; the protocol requires the role fields
+ * to be empty there, and readers fall back to `oppAddress` for every role. Every
+ * field may be empty while the remote contracts are not deployed yet.
+ */
+export interface ChainOutpostAddresses {
+  /** EVM: the OPP contract. SVM: the outpost program id. */
+  oppAddress: string
+  /** EVM: the OPPInbound contract. Must be empty for SVM. */
+  oppInboundAddress: string
+  /** EVM: the OperatorRegistry contract. Must be empty for SVM. */
+  operatorRegistryAddress: string
+  /** EVM: the source swap-deposit contract. Must be empty for SVM. */
+  sourceDepositAddress: string
+}
+
 /** User-facing chain registration data. */
 export interface ChainRegistration {
   /** VM/signing family used by the registered chain. */
@@ -26,6 +45,11 @@ export interface ChainRegistration {
   name: string
   /** Human-readable chain description. */
   description: string
+  /**
+   * Remote outpost contract identities. Omit to register the chain before its
+   * remote contracts exist, then supply them later with `setoutpost`.
+   */
+  outpost?: Partial<ChainOutpostAddresses>
 }
 
 /** Options for creating an unsigned `regchain` action. */
@@ -38,6 +62,19 @@ export interface CreateRegisterChainActionOptions {
   contract?: NameType
 }
 
+/** Options for creating an unsigned `setoutpost` action. */
+export interface CreateSetOutpostActionOptions {
+  /** Stable protocol chain code whose deployment is being replaced. */
+  code: ChainSlugName
+  /** Replacement contract identities. The whole set is replaced, so a caller
+   * updating one address must resend the others. */
+  outpost: Partial<ChainOutpostAddresses>
+  /** Permission levels authorizing the action. */
+  authorization: ContractPermissionLevel[]
+  /** Chain registry contract account override. */
+  contract?: NameType
+}
+
 /** Options for creating an unsigned `activchain` action. */
 export interface CreateActivateChainActionOptions {
   /** Stable protocol chain code to activate. */
@@ -82,6 +119,8 @@ export interface ChainRecord {
   registeredAtMs: bigint
   /** Activation time in Unix milliseconds, or zero before activation. */
   activatedAtMs: bigint
+  /** Remote outpost contract identities recorded for this chain. */
+  outpost: ChainOutpostAddresses
   /** Original generated registry row. */
   raw: SysioContracts.SysioChainsChainRowType
 }
diff --git a/packages/sdk-core/src/types/SysioContractTypes.ts b/packages/sdk-core/src/types/SysioContractTypes.ts
index f80a5ea..64fe118 100644
--- a/packages/sdk-core/src/types/SysioContractTypes.ts
+++ b/packages/sdk-core/src/types/SysioContractTypes.ts
@@ -316,6 +316,15 @@ export interface SysioChainsChainRowType {
   active: boolean
   registered_at_ms: number | string
   activated_at_ms: number | string
+  outpost: SysioChainsOutpostAddrsType
+}
+
+/** sysio.chains::outpost_addrs (type) */
+export interface SysioChainsOutpostAddrsType {
+  opp_addr: string
+  opp_inbound_addr: string
+  operator_registry_addr: string
+  source_deposit_addr: string
 }
 
 /** sysio.chains::regchain (action) */
@@ -325,6 +334,13 @@ export interface SysioChainsRegchainAction {
   external_chain_id: number
   name: string
   description: string
+  outpost: SysioChainsOutpostAddrsType
+}
+
+/** sysio.chains::setoutpost (action) */
+export interface SysioChainsSetoutpostAction {
+  code: SysioChainsSlugNameType
+  outpost: SysioChainsOutpostAddrsType
 }
 
 /** sysio.chains::slug_name (type) */
@@ -337,6 +353,7 @@ export interface SysioChainsContract {
   actions: {
     activchain: SysioChainsActivchainAction
     regchain: SysioChainsRegchainAction
+    setoutpost: SysioChainsSetoutpostAction
   }
   tables: {
     chains: SysioChainsChainRowType
@@ -3704,7 +3721,7 @@ export const SysioContractDefinitions: {
 } = {
   [SysioContractName.authex]: { name: SysioContractName.authex, account: "sysio.authex", actions: ["clearlinks", "createlink", "recordlink"], tables: ["links"] },
   [SysioContractName.bios]: { name: SysioContractName.bios, account: "sysio", actions: ["activate", "deleteauth", "linkauth", "newaccount", "reqactivated", "reqauth", "setabi", "setalimits", "setcode", "setfinalizer", "setparams", "setpriv", "setprodkeys", "setprods", "unlinkauth", "updateauth"], tables: ["abihash"] },
-  [SysioContractName.chains]: { name: SysioContractName.chains, account: "sysio.chains", actions: ["activchain", "regchain"], tables: ["chains"] },
+  [SysioContractName.chains]: { name: SysioContractName.chains, account: "sysio.chains", actions: ["activchain", "regchain", "setoutpost"], tables: ["chains"] },
   [SysioContractName.chalg]: { name: SysioContractName.chalg, account: "sysio.chalg", actions: ["chkdispute", "chkuwchal", "claimbond", "opendispute", "openuwchal", "slashop", "uwchalbond", "votedispute", "voteuwchal"], tables: ["bondcredits", "chalgstate", "disputes", "disputevote", "uwchals", "uwchalvote"] },
   [SysioContractName.councl]: { name: SysioContractName.councl, account: "sysio.councl", actions: ["addcandidate", "finalizeinit", "forceassign", "forceback", "loadtier", "purge", "repcandidate", "reset", "rmcandidate", "settle", "startinit", "stir", "vote"], tables: ["candidates", "config", "council", "roster", "state", "tier2", "tier3", "tier3remap"] },
   [SysioContractName.dclaim]: { name: SysioContractName.dclaim, account: "sysio.dclaim", actions: ["claim", "flushexpired", "importdone", "importseed", "linkswept", "onreward", "setclmwindow", "setconfig"], tables: ["capcfg", "capcounters", "pclaims", "rwdcursors", "unmapped"] },
diff --git a/packages/sdk-core/tests/contracts/sysio/chains/Actions.test.ts b/packages/sdk-core/tests/contracts/sysio/chains/Actions.test.ts
index 338ff64..e98b634 100644
--- a/packages/sdk-core/tests/contracts/sysio/chains/Actions.test.ts
+++ b/packages/sdk-core/tests/contracts/sysio/chains/Actions.test.ts
@@ -4,12 +4,27 @@ import { SysioChainsChainkind } from "@wireio/sdk-core/types/SysioContractTypes"
 const {
   ChainsActivateChain,
   ChainsRegisterChain,
+  ChainsSetOutpost,
   createActivateChainAction,
   createActivateChainActionData,
   createRegisterChainAction,
-  createRegisterChainActionData
+  createRegisterChainActionData,
+  createSetOutpostAction,
+  createSetOutpostActionData
 } = contracts.sysio.chains
 
+const EVM_OPP = "0x5FbDB2315678afecb367f032d93F642f64180aa3",
+  EVM_INBOUND = "0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512",
+  EVM_OPREG = "0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0",
+  EVM_DEPOSIT = "0xCf7Ed3AccA5a467e9e704C703E8D87F634fB0Fc9",
+  SVM_PROGRAM = "So11111111111111111111111111111111111111112",
+  EMPTY_OUTPOST = {
+    opp_addr: "",
+    opp_inbound_addr: "",
+    operator_registry_addr: "",
+    source_deposit_addr: ""
+  }
+
 const REGISTRATION = {
   kind: SysioChainsChainkind.CHAIN_KIND_EVM,
   code: "POLYGON",
@@ -25,7 +40,10 @@ describe("sysio.chains action helpers", () => {
       code: { value: SlugName.from("POLYGON") },
       external_chain_id: 137,
       name: "Polygon",
-      description: "Polygon EVM outpost"
+      description: "Polygon EVM outpost",
+      // Registering before the remote contracts exist is legal; setoutpost
+      // fills them in later, and both operator daemons skip the chain meanwhile.
+      outpost: EMPTY_OUTPOST
     })
     expect(createActivateChainActionData("POLYGON")).toEqual({
       code: { value: SlugName.from("POLYGON") }
@@ -52,9 +70,62 @@ describe("sysio.chains action helpers", () => {
     expect(Number(registerData.external_chain_id)).toBe(137)
     expect(registerData.name).toBe("Polygon")
     expect(registerData.description).toBe("Polygon EVM outpost")
+    expect(registerData.outpost.opp_addr).toBe("")
     expect(Number(activateData.code.value)).toBe(SlugName.from("POLYGON"))
   })
 
+  test("carries every EVM contract role through regchain", () => {
+    expect(
+      createRegisterChainActionData({
+        ...REGISTRATION,
+        outpost: {
+          oppAddress: EVM_OPP,
+          oppInboundAddress: EVM_INBOUND,
+          operatorRegistryAddress: EVM_OPREG,
+          sourceDepositAddress: EVM_DEPOSIT
+        }
+      }).outpost
+    ).toEqual({
+      opp_addr: EVM_OPP,
+      opp_inbound_addr: EVM_INBOUND,
+      operator_registry_addr: EVM_OPREG,
+      source_deposit_addr: EVM_DEPOSIT
+    })
+  })
+
+  test("defaults an omitted role to empty rather than dropping the field", () => {
+    // An SVM outpost is one program: only opp_addr is set, and the protocol
+    // REQUIRES the other three to be empty.
+    expect(
+      createSetOutpostActionData("SOLANA", { oppAddress: SVM_PROGRAM })
+    ).toEqual({
+      code: { value: SlugName.from("SOLANA") },
+      outpost: { ...EMPTY_OUTPOST, opp_addr: SVM_PROGRAM }
+    })
+  })
+
+  test("serializes setoutpost through the shared contract proxy", () => {
+    const action = createSetOutpostAction({
+        code: "POLYGON",
+        outpost: {
+          oppAddress: EVM_OPP,
+          oppInboundAddress: EVM_INBOUND,
+          operatorRegistryAddress: EVM_OPREG,
+          sourceDepositAddress: EVM_DEPOSIT
+        },
+        authorization: ["sysio.chains@active"]
+      }),
+      data = action.decodeData(ChainsSetOutpost)
+
+    expect(action.account.toString()).toBe("sysio.chains")
+    expect(action.name.toString()).toBe("setoutpost")
+    expect(Number(data.code.value)).toBe(SlugName.from("POLYGON"))
+    expect(data.outpost.opp_addr).toBe(EVM_OPP)
+    expect(data.outpost.opp_inbound_addr).toBe(EVM_INBOUND)
+    expect(data.outpost.operator_registry_addr).toBe(EVM_OPREG)
+    expect(data.outpost.source_deposit_addr).toBe(EVM_DEPOSIT)
+  })
+
   test("rejects external chain identifiers outside uint32", () => {
     expect(() =>
       createRegisterChainActionData({