Add multi-repository support for chains

Chains can now have multiple repositories attached, with one marked as
primary. Repositories are used by contracts created from chain definitions.

Backend changes:
- Add chain_repositories table migration
- Add ChainRepository model with CRUD operations
- Add API endpoints for listing, adding, deleting repositories
- Add endpoint to set a repository as primary
- Update Chain and ChainEditorData models to use repositories
- Update chain parser to support repositories in YAML format
- Remove deprecated repository_url/local_path from Chain

Frontend changes:
- Add ChainRepository interface and API functions
- Add repository section to ChainEditor showing attached repos
- Add modal for adding new repositories (remote or local)
- Support setting primary repository and removing repositories

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

9 files changed, 1030 insertions, 61 deletions

diff --git a/makima/frontend/src/components/chains/ChainEditor.tsx b/makima/frontend/src/components/chains/ChainEditor.tsx
index 5b77170..6b9aa70 100644
--- a/makima/frontend/src/components/chains/ChainEditor.tsx
+++ b/makima/frontend/src/components/chains/ChainEditor.tsx
@@ -1,4 +1,4 @@
-import { useState, useCallback, useEffect, useMemo } from "react";
+import { useState, useCallback, useEffect } from "react";
 import {
   ReactFlow,
   Node,
@@ -7,9 +7,7 @@ import {
   Background,
   useNodesState,
   useEdgesState,
-  addEdge,
   Connection,
-  NodeProps,
   Handle,
   Position,
   BackgroundVariant,
@@ -24,6 +22,8 @@ import type {
   ChainContractDefinition,
   ChainDefinitionGraphResponse,
   AddContractDefinitionRequest,
+  ChainRepository,
+  AddChainRepositoryRequest,
 } from "../../lib/api";
 import {
   listChainDefinitions,
@@ -33,6 +33,10 @@ import {
   getChainDefinitionGraph,
   startChain,
   stopChain,
+  listChainRepositories,
+  addChainRepository,
+  deleteChainRepository,
+  setChainRepositoryPrimary,
 } from "../../lib/api";
 
 const statusColors: Record<string, string> = {
@@ -58,7 +62,14 @@ const GRID_SPACING_X = 280;
 const GRID_SPACING_Y = 120;
 
 // Custom node component for definitions
-function DefinitionNode({ data, selected }: NodeProps) {
+function DefinitionNodeComponent({
+  data,
+  selected,
+}: {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  data: any;
+  selected?: boolean;
+}) {
   const isCheckpoint = data.contractType === "checkpoint";
   const status = data.isInstantiated ? data.contractStatus || "pending" : "pending";
   const colors = getStatusColor(status, isCheckpoint);
@@ -130,7 +141,14 @@ function DefinitionNode({ data, selected }: NodeProps) {
 }
 
 // Custom node for contracts (active chains)
-function ContractNode({ data, selected }: NodeProps) {
+function ContractNodeComponent({
+  data,
+  selected,
+}: {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  data: any;
+  selected?: boolean;
+}) {
   const colors = getStatusColor(data.status);
 
   return (
@@ -184,9 +202,10 @@ function ContractNode({ data, selected }: NodeProps) {
   );
 }
 
-const nodeTypes = {
-  definition: DefinitionNode,
-  contract: ContractNode,
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const nodeTypes: Record<string, any> = {
+  definition: DefinitionNodeComponent,
+  contract: ContractNodeComponent,
 };
 
 function getStatusColor(status: string, isCheckpoint = false) {
@@ -233,28 +252,32 @@ export function ChainEditor({
   const [isStopping, setIsStopping] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [selectedNodeId, setSelectedNodeId] = useState<string | null>(null);
+  const [repositories, setRepositories] = useState<ChainRepository[]>([]);
+  const [showAddRepo, setShowAddRepo] = useState(false);
 
-  const [nodes, setNodes, onNodesChange] = useNodesState([]);
-  const [edges, setEdges, onEdgesChange] = useEdgesState([]);
+  const [nodes, setNodes, onNodesChange] = useNodesState([] as Node[]);
+  const [edges, setEdges, onEdgesChange] = useEdgesState([] as Edge[]);
 
   const showDefinitions = chain.status === "pending" || chain.status === "archived";
   const canEdit = chain.status === "pending";
 
-  // Load definitions when chain changes
+  // Load definitions and repositories when chain changes
   useEffect(() => {
-    async function loadDefinitions() {
+    async function loadData() {
       try {
-        const [defs, defGraph] = await Promise.all([
+        const [defs, defGraph, repos] = await Promise.all([
           listChainDefinitions(chain.id),
           getChainDefinitionGraph(chain.id),
+          listChainRepositories(chain.id),
         ]);
         setDefinitions(defs);
         setDefinitionGraph(defGraph);
+        setRepositories(repos);
       } catch (err) {
-        console.error("Failed to load definitions:", err);
+        console.error("Failed to load data:", err);
       }
     }
-    loadDefinitions();
+    loadData();
   }, [chain.id]);
 
   // Convert definitions/contracts to React Flow nodes and edges
@@ -523,6 +546,51 @@ export function ChainEditor({
     [chain.id, definitions]
   );
 
+  // Repository handlers
+  const handleAddRepository = useCallback(
+    async (req: AddChainRepositoryRequest) => {
+      try {
+        await addChainRepository(chain.id, req);
+        const repos = await listChainRepositories(chain.id);
+        setRepositories(repos);
+        setShowAddRepo(false);
+      } catch (err) {
+        console.error("Failed to add repository:", err);
+        setError(err instanceof Error ? err.message : "Failed to add repository");
+      }
+    },
+    [chain.id]
+  );
+
+  const handleDeleteRepository = useCallback(
+    async (repoId: string) => {
+      if (!confirm("Remove this repository from the chain?")) return;
+      try {
+        await deleteChainRepository(chain.id, repoId);
+        const repos = await listChainRepositories(chain.id);
+        setRepositories(repos);
+      } catch (err) {
+        console.error("Failed to delete repository:", err);
+        setError(err instanceof Error ? err.message : "Failed to delete repository");
+      }
+    },
+    [chain.id]
+  );
+
+  const handleSetPrimary = useCallback(
+    async (repoId: string) => {
+      try {
+        await setChainRepositoryPrimary(chain.id, repoId);
+        const repos = await listChainRepositories(chain.id);
+        setRepositories(repos);
+      } catch (err) {
+        console.error("Failed to set primary:", err);
+        setError(err instanceof Error ? err.message : "Failed to set primary repository");
+      }
+    },
+    [chain.id]
+  );
+
   return (
     <div className="panel h-full flex flex-col">
       {/* Header */}
@@ -583,6 +651,67 @@ export function ChainEditor({
         )}
       </div>
 
+      {/* Repository section */}
+      <div className="px-3 py-2 border-b border-[rgba(117,170,252,0.2)] bg-[#0a1628]/50">
+        <div className="flex items-center justify-between">
+          <span className="font-mono text-[10px] text-[#8b949e] uppercase">
+            Repositories ({repositories.length})
+          </span>
+          {canEdit && (
+            <button
+              onClick={() => setShowAddRepo(true)}
+              className="font-mono text-[10px] text-[#9bc3ff] hover:text-[#dbe7ff]"
+            >
+              + Add
+            </button>
+          )}
+        </div>
+        {repositories.length > 0 && (
+          <div className="flex flex-wrap gap-2 mt-2">
+            {repositories.map((repo) => (
+              <div
+                key={repo.id}
+                className={`flex items-center gap-1 px-2 py-1 rounded font-mono text-xs ${
+                  repo.isPrimary
+                    ? "bg-[#75aafc]/20 border border-[#75aafc]/50 text-[#75aafc]"
+                    : "bg-[#1a2744] border border-[rgba(117,170,252,0.2)] text-[#9bc3ff]"
+                }`}
+              >
+                <RepoIcon className="w-3 h-3" />
+                <span className="truncate max-w-[150px]" title={repo.name}>
+                  {repo.name}
+                </span>
+                {repo.isPrimary && (
+                  <span className="text-[8px] uppercase ml-1">primary</span>
+                )}
+                {canEdit && !repo.isPrimary && (
+                  <button
+                    onClick={() => handleSetPrimary(repo.id)}
+                    className="ml-1 text-[8px] text-[#556677] hover:text-[#9bc3ff]"
+                    title="Set as primary"
+                  >
+                    ★
+                  </button>
+                )}
+                {canEdit && (
+                  <button
+                    onClick={() => handleDeleteRepository(repo.id)}
+                    className="ml-1 text-[10px] text-[#556677] hover:text-red-400"
+                  >
+                    ✕
+                  </button>
+                )}
+              </div>
+            ))}
+          </div>
+        )}
+        {repositories.length === 0 && (
+          <p className="font-mono text-[10px] text-[#556677] mt-1">
+            No repositories attached. {canEdit && "Add one to use with contracts."}
+          </p>
+        )}
+      </div>
+
       {/* Main content */}
       <div className="flex-1 flex min-h-0">
         {/* React Flow Canvas */}
@@ -713,6 +842,14 @@ export function ChainEditor({
           onCancel={() => setShowAddDefinition(false)}
         />
       )}
+
+      {/* Add Repository Modal */}
+      {showAddRepo && (
+        <AddRepositoryModal
+          onSubmit={handleAddRepository}
+          onCancel={() => setShowAddRepo(false)}
+        />
+      )}
     </div>
   );
 }
@@ -985,3 +1122,157 @@ function CheckIcon({ className }: { className?: string }) {
     </svg>
   );
 }
+
+function RepoIcon({ className }: { className?: string }) {
+  return (
+    <svg className={className} fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
+      <path
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        d="M3 7v10a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2h-6l-2-2H5a2 2 0 00-2 2z"
+      />
+    </svg>
+  );
+}
+
+// Add Repository Modal
+interface AddRepositoryModalProps {
+  onSubmit: (req: AddChainRepositoryRequest) => void;
+  onCancel: () => void;
+}
+
+function AddRepositoryModal({ onSubmit, onCancel }: AddRepositoryModalProps) {
+  const [name, setName] = useState("");
+  const [repositoryUrl, setRepositoryUrl] = useState("");
+  const [localPath, setLocalPath] = useState("");
+  const [sourceType, setSourceType] = useState<"remote" | "local">("remote");
+  const [isPrimary, setIsPrimary] = useState(false);
+
+  const handleSubmit = () => {
+    if (!name.trim()) return;
+    if (sourceType === "remote" && !repositoryUrl.trim()) return;
+    if (sourceType === "local" && !localPath.trim()) return;
+
+    const req: AddChainRepositoryRequest = {
+      name: name.trim(),
+      sourceType,
+      isPrimary,
+      ...(sourceType === "remote"
+        ? { repositoryUrl: repositoryUrl.trim() }
+        : { localPath: localPath.trim() }),
+    };
+    onSubmit(req);
+  };
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 p-4">
+      <div className="w-full max-w-lg p-6 bg-[#0a1628] border border-[rgba(117,170,252,0.3)]">
+        <h3 className="font-mono text-sm text-[#75aafc] uppercase mb-4">Add Repository</h3>
+
+        <div className="space-y-4">
+          {/* Name */}
+          <div>
+            <label className="block font-mono text-[10px] text-[#8b949e] uppercase mb-1">
+              Name *
+            </label>
+            <input
+              type="text"
+              value={name}
+              onChange={(e) => setName(e.target.value)}
+              className="w-full px-3 py-2 bg-[#050d18] border border-[rgba(117,170,252,0.3)] font-mono text-sm text-[#dbe7ff] focus:border-[#75aafc] focus:outline-none"
+              placeholder="e.g., Main Repository"
+            />
+          </div>
+
+          {/* Source Type */}
+          <div>
+            <label className="block font-mono text-[10px] text-[#8b949e] uppercase mb-1">
+              Source Type
+            </label>
+            <div className="flex gap-4">
+              <label className="flex items-center gap-2 font-mono text-sm text-[#dbe7ff]">
+                <input
+                  type="radio"
+                  checked={sourceType === "remote"}
+                  onChange={() => setSourceType("remote")}
+                  className="accent-[#75aafc]"
+                />
+                Remote (URL)
+              </label>
+              <label className="flex items-center gap-2 font-mono text-sm text-[#dbe7ff]">
+                <input
+                  type="radio"
+                  checked={sourceType === "local"}
+                  onChange={() => setSourceType("local")}
+                  className="accent-[#75aafc]"
+                />
+                Local Path
+              </label>
+            </div>
+          </div>
+
+          {/* Repository URL or Local Path */}
+          {sourceType === "remote" ? (
+            <div>
+              <label className="block font-mono text-[10px] text-[#8b949e] uppercase mb-1">
+                Repository URL *
+              </label>
+              <input
+                type="text"
+                value={repositoryUrl}
+                onChange={(e) => setRepositoryUrl(e.target.value)}
+                className="w-full px-3 py-2 bg-[#050d18] border border-[rgba(117,170,252,0.3)] font-mono text-sm text-[#dbe7ff] focus:border-[#75aafc] focus:outline-none"
+                placeholder="https://github.com/user/repo"
+              />
+            </div>
+          ) : (
+            <div>
+              <label className="block font-mono text-[10px] text-[#8b949e] uppercase mb-1">
+                Local Path *
+              </label>
+              <input
+                type="text"
+                value={localPath}
+                onChange={(e) => setLocalPath(e.target.value)}
+                className="w-full px-3 py-2 bg-[#050d18] border border-[rgba(117,170,252,0.3)] font-mono text-sm text-[#dbe7ff] focus:border-[#75aafc] focus:outline-none"
+                placeholder="/path/to/local/repo"
+              />
+            </div>
+          )}
+
+          {/* Primary checkbox */}
+          <label className="flex items-center gap-2 font-mono text-sm text-[#dbe7ff]">
+            <input
+              type="checkbox"
+              checked={isPrimary}
+              onChange={(e) => setIsPrimary(e.target.checked)}
+              className="accent-[#75aafc]"
+            />
+            Set as primary repository
+          </label>
+        </div>
+
+        {/* Actions */}
+        <div className="flex justify-end gap-2 mt-6">
+          <button
+            onClick={onCancel}
+            className="px-4 py-2 font-mono text-xs text-[#8b949e] border border-[rgba(117,170,252,0.3)] hover:border-[#75aafc] transition-colors"
+          >
+            Cancel
+          </button>
+          <button
+            onClick={handleSubmit}
+            disabled={
+              !name.trim() ||
+              (sourceType === "remote" && !repositoryUrl.trim()) ||
+              (sourceType === "local" && !localPath.trim())
+            }
+            className="px-4 py-2 font-mono text-xs text-[#dbe7ff] bg-[#0f3c78] border border-[#3f6fb3] hover:bg-[#153667] transition-colors disabled:opacity-50"
+          >
+            Add Repository
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/makima/frontend/src/lib/api.ts b/makima/frontend/src/lib/api.ts
index d68c1ad..2f4ee62 100644
--- a/makima/frontend/src/lib/api.ts
+++ b/makima/frontend/src/lib/api.ts
@@ -3025,6 +3025,20 @@ export interface ChainSummary {
   updatedAt: string;
 }
 
+/** Chain repository */
+export interface ChainRepository {
+  id: string;
+  chainId: string;
+  name: string;
+  repositoryUrl: string | null;
+  localPath: string | null;
+  sourceType: string;
+  status: string;
+  isPrimary: boolean;
+  createdAt: string;
+  updatedAt: string;
+}
+
 /** Full chain with contracts */
 export interface Chain {
   id: string;
@@ -3036,8 +3050,6 @@ export interface Chain {
   loopMaxIterations: number | null;
   loopCurrentIteration: number | null;
   loopProgressCheck: string | null;
-  repositoryUrl: string | null;
-  localPath: string | null;
   version: number;
   createdAt: string;
   updatedAt: string;
@@ -3061,6 +3073,7 @@ export interface ChainContractDetail {
 /** Chain with contracts (chain fields are flattened via serde(flatten)) */
 export interface ChainWithContracts extends Chain {
   contracts: ChainContractDetail[];
+  repositories: ChainRepository[];
 }
 
 /** Node in chain graph visualization */
@@ -3105,12 +3118,20 @@ export interface ChainListResponse {
   total: number;
 }
 
+/** Add chain repository request */
+export interface AddChainRepositoryRequest {
+  name: string;
+  repositoryUrl?: string;
+  localPath?: string;
+  sourceType?: string;
+  isPrimary?: boolean;
+}
+
 /** Create chain request */
 export interface CreateChainRequest {
   name: string;
   description?: string;
-  repositoryUrl?: string;
-  localPath?: string;
+  repositories?: AddChainRepositoryRequest[];
   loopEnabled?: boolean;
   loopMaxIterations?: number;
   loopProgressCheck?: string;
@@ -3446,3 +3467,63 @@ export async function stopChain(chainId: string): Promise<{ stopped: boolean; st
   }
   return res.json();
 }
+
+// ============================================================================
+// Chain Repository Operations
+// ============================================================================
+
+/** List repositories for a chain */
+export async function listChainRepositories(chainId: string): Promise<ChainRepository[]> {
+  const res = await authFetch(`${API_BASE}/api/v1/chains/${chainId}/repositories`);
+  if (!res.ok) {
+    throw new Error(`Failed to list chain repositories: ${res.statusText}`);
+  }
+  return res.json();
+}
+
+/** Add a repository to a chain */
+export async function addChainRepository(
+  chainId: string,
+  req: AddChainRepositoryRequest
+): Promise<ChainRepository> {
+  const res = await authFetch(`${API_BASE}/api/v1/chains/${chainId}/repositories`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(req),
+  });
+  if (!res.ok) {
+    const error = await res.json().catch(() => ({ message: res.statusText }));
+    throw new Error(error.message || `Failed to add chain repository: ${res.statusText}`);
+  }
+  return res.json();
+}
+
+/** Delete a repository from a chain */
+export async function deleteChainRepository(
+  chainId: string,
+  repositoryId: string
+): Promise<{ deleted: boolean }> {
+  const res = await authFetch(
+    `${API_BASE}/api/v1/chains/${chainId}/repositories/${repositoryId}`,
+    { method: "DELETE" }
+  );
+  if (!res.ok) {
+    throw new Error(`Failed to delete chain repository: ${res.statusText}`);
+  }
+  return res.json();
+}
+
+/** Set a repository as primary for a chain */
+export async function setChainRepositoryPrimary(
+  chainId: string,
+  repositoryId: string
+): Promise<ChainRepository> {
+  const res = await authFetch(
+    `${API_BASE}/api/v1/chains/${chainId}/repositories/${repositoryId}/primary`,
+    { method: "PUT" }
+  );
+  if (!res.ok) {
+    throw new Error(`Failed to set chain repository as primary: ${res.statusText}`);
+  }
+  return res.json();
+}
diff --git a/makima/migrations/20260205000000_chain_repositories.sql b/makima/migrations/20260205000000_chain_repositories.sql
new file mode 100644
index 0000000..5be8cf2
--- /dev/null
+++ b/makima/migrations/20260205000000_chain_repositories.sql
@@ -0,0 +1,27 @@
+-- Chain repositories - allow chains to have multiple repositories
+-- Similar to contract_repositories but for chains
+CREATE TABLE IF NOT EXISTS chain_repositories (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    chain_id UUID NOT NULL REFERENCES chains(id) ON DELETE CASCADE,
+    name VARCHAR(255) NOT NULL,                     -- display name / repo name
+    repository_url VARCHAR(512),                    -- NULL for local repos
+    local_path VARCHAR(512),                        -- local filesystem path (for local repos)
+    source_type VARCHAR(32) NOT NULL DEFAULT 'remote', -- remote/local/managed
+    status VARCHAR(32) NOT NULL DEFAULT 'ready',    -- ready/pending/creating/failed
+    is_primary BOOLEAN NOT NULL DEFAULT false,      -- primary repo for contract defaults
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- source_type values:
+--   'remote'  = existing remote repo (GitHub, GitLab, etc) - has repository_url
+--   'local'   = existing local repo - has local_path
+--   'managed' = new repo created/managed by Makima daemon - gets repository_url after creation
+
+CREATE INDEX idx_chain_repositories_chain_id ON chain_repositories(chain_id);
+-- Only one primary per chain
+CREATE UNIQUE INDEX idx_chain_repositories_primary ON chain_repositories(chain_id) WHERE is_primary = true;
+
+-- Remove the old single repository fields from chains table (they're now in chain_repositories)
+ALTER TABLE chains DROP COLUMN IF EXISTS repository_url;
+ALTER TABLE chains DROP COLUMN IF EXISTS local_path;
diff --git a/makima/src/daemon/chain/parser.rs b/makima/src/daemon/chain/parser.rs
index 0f16710..3851d1f 100644
--- a/makima/src/daemon/chain/parser.rs
+++ b/makima/src/daemon/chain/parser.rs
@@ -20,6 +20,27 @@ pub enum ParseError {
     ValidationError(String),
 }
 
+/// Repository definition in a chain.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct RepositoryDefinition {
+    /// Name of the repository
+    pub name: String,
+    /// Repository URL (for remote repos)
+    pub repository_url: Option<String>,
+    /// Local path (for local repos)
+    pub local_path: Option<String>,
+    /// Source type: remote, local, or managed
+    #[serde(default = "default_source_type")]
+    pub source_type: String,
+    /// Whether this is the primary repository
+    #[serde(default)]
+    pub is_primary: bool,
+}
+
+fn default_source_type() -> String {
+    "remote".to_string()
+}
+
 /// Chain definition parsed from YAML.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ChainDefinition {
@@ -27,11 +48,9 @@ pub struct ChainDefinition {
     pub name: String,
     /// Optional description
     pub description: Option<String>,
-    /// Repository URL (optional - contracts may have their own repos)
-    #[serde(alias = "repo")]
-    pub repository_url: Option<String>,
-    /// Local path for repository
-    pub local_path: Option<String>,
+    /// Repositories for this chain
+    #[serde(default)]
+    pub repositories: Vec<RepositoryDefinition>,
     /// Contracts in this chain
     pub contracts: Vec<ContractDefinition>,
     /// Loop configuration
diff --git a/makima/src/daemon/chain/runner.rs b/makima/src/daemon/chain/runner.rs
index 9c6f6b4..dfbcfa7 100644
--- a/makima/src/daemon/chain/runner.rs
+++ b/makima/src/daemon/chain/runner.rs
@@ -14,8 +14,8 @@ use thiserror::Error;
 use super::dag::{topological_sort, validate_dag, DagError};
 use super::parser::{parse_chain_file, ChainDefinition, ParseError};
 use crate::db::models::{
-    CreateChainContractRequest, CreateChainDeliverableRequest, CreateChainRequest,
-    CreateChainTaskRequest,
+    AddChainRepositoryRequest, CreateChainContractRequest, CreateChainDeliverableRequest,
+    CreateChainRequest, CreateChainTaskRequest,
 };
 
 /// Error type for chain runner operations.
@@ -100,11 +100,27 @@ impl ChainRunner {
                 None => (None, None, None),
             };
 
+        // Convert repository definitions to API format
+        let repositories: Vec<AddChainRepositoryRequest> = chain
+            .repositories
+            .iter()
+            .map(|r| AddChainRepositoryRequest {
+                name: r.name.clone(),
+                repository_url: r.repository_url.clone(),
+                local_path: r.local_path.clone(),
+                source_type: r.source_type.clone(),
+                is_primary: r.is_primary,
+            })
+            .collect();
+
         CreateChainRequest {
             name: chain.name.clone(),
             description: chain.description.clone(),
-            repository_url: chain.repository_url.clone(),
-            local_path: chain.local_path.clone(),
+            repositories: if repositories.is_empty() {
+                None
+            } else {
+                Some(repositories)
+            },
             loop_enabled,
             loop_max_iterations,
             loop_progress_check,
diff --git a/makima/src/db/models.rs b/makima/src/db/models.rs
index 4e569ec..30e1603 100644
--- a/makima/src/db/models.rs
+++ b/makima/src/db/models.rs
@@ -2652,16 +2652,40 @@ pub struct Chain {
     pub loop_current_iteration: Option<i32>,
     /// Progress check prompt/criteria for evaluating loop completion
     pub loop_progress_check: Option<String>,
-    /// Repository URL for contracts in this chain (optional)
-    pub repository_url: Option<String>,
-    /// Local path for contracts in this chain (optional)
-    pub local_path: Option<String>,
     /// Version for optimistic locking
     pub version: i32,
     pub created_at: DateTime<Utc>,
     pub updated_at: DateTime<Utc>,
 }
 
+/// Chain repository record from the database
+#[derive(Debug, Clone, FromRow, Serialize, Deserialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ChainRepository {
+    pub id: Uuid,
+    pub chain_id: Uuid,
+    pub name: String,
+    pub repository_url: Option<String>,
+    pub local_path: Option<String>,
+    pub source_type: String,
+    pub status: String,
+    pub is_primary: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+impl ChainRepository {
+    /// Parse source_type string to RepositorySourceType enum
+    pub fn source_type_enum(&self) -> Result<RepositorySourceType, String> {
+        self.source_type.parse()
+    }
+
+    /// Parse status string to RepositoryStatus enum
+    pub fn status_enum(&self) -> Result<RepositoryStatus, String> {
+        self.status.parse()
+    }
+}
+
 impl Chain {
     /// Parse status string to ChainStatus enum
     pub fn status_enum(&self) -> Result<ChainStatus, String> {
@@ -2724,6 +2748,7 @@ pub struct ChainWithContracts {
     #[serde(flatten)]
     pub chain: Chain,
     pub contracts: Vec<ChainContractDetail>,
+    pub repositories: Vec<ChainRepository>,
 }
 
 /// Contract detail within a chain (includes contract info + chain link info)
@@ -2790,10 +2815,8 @@ pub struct CreateChainRequest {
     pub name: String,
     /// Optional description
     pub description: Option<String>,
-    /// Repository URL for contracts in this chain
-    pub repository_url: Option<String>,
-    /// Local path for contracts in this chain
-    pub local_path: Option<String>,
+    /// Repositories for this chain
+    pub repositories: Option<Vec<AddChainRepositoryRequest>>,
     /// Enable loop mode for iterative execution
     #[serde(default)]
     pub loop_enabled: Option<bool>,
@@ -2805,6 +2828,28 @@ pub struct CreateChainRequest {
     pub contracts: Option<Vec<CreateChainContractRequest>>,
 }
 
+/// Request to add a repository to a chain
+#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct AddChainRepositoryRequest {
+    /// Display name for the repository
+    pub name: String,
+    /// Remote repository URL (for remote repos)
+    pub repository_url: Option<String>,
+    /// Local filesystem path (for local repos)
+    pub local_path: Option<String>,
+    /// Source type: remote, local, or managed
+    #[serde(default = "default_source_type")]
+    pub source_type: String,
+    /// Whether this is the primary repository
+    #[serde(default)]
+    pub is_primary: bool,
+}
+
+fn default_source_type() -> String {
+    "remote".to_string()
+}
+
 /// Request to create a contract within a chain
 #[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
 #[serde(rename_all = "camelCase")]
@@ -2934,8 +2979,7 @@ pub struct ChainEditorData {
     pub id: Option<Uuid>,
     pub name: String,
     pub description: Option<String>,
-    pub repository_url: Option<String>,
-    pub local_path: Option<String>,
+    pub repositories: Vec<ChainRepository>,
     pub loop_enabled: bool,
     pub loop_max_iterations: Option<i32>,
     pub loop_progress_check: Option<String>,
diff --git a/makima/src/db/repository.rs b/makima/src/db/repository.rs
index ec233ba..2b595b5 100644
--- a/makima/src/db/repository.rs
+++ b/makima/src/db/repository.rs
@@ -6,20 +6,20 @@ use sqlx::PgPool;
 use uuid::Uuid;
 
 use super::models::{
-    AddContractDefinitionRequest, AddContractToChainRequest, Chain, ChainContract,
-    ChainContractDefinition, ChainContractDetail, ChainDefinitionGraphNode,
+    AddChainRepositoryRequest, AddContractDefinitionRequest, AddContractToChainRequest, Chain,
+    ChainContract, ChainContractDefinition, ChainContractDetail, ChainDefinitionGraphNode,
     ChainDefinitionGraphResponse, ChainEditorContract, ChainEditorData, ChainEditorDeliverable,
     ChainEditorEdge, ChainEditorNode, ChainEditorTask, ChainEvent, ChainGraphEdge, ChainGraphNode,
-    ChainGraphResponse, ChainSummary, ChainWithContracts, CheckpointPatch, CheckpointPatchInfo,
-    Contract, ContractChatConversation, ContractChatMessageRecord, ContractEvent,
-    ContractRepository, ContractSummary, ContractTypeTemplateRecord, ConversationMessage,
-    ConversationSnapshot, CreateChainRequest, CreateContractRequest, CreateFileRequest,
-    CreateTaskRequest, CreateTemplateRequest, Daemon, DaemonTaskAssignment, DaemonWithCapacity,
-    DeliverableDefinition, File, FileSummary, FileVersion, HistoryEvent, HistoryQueryFilters,
-    MeshChatConversation, MeshChatMessageRecord, PhaseChangeResult, PhaseConfig, PhaseDefinition,
-    SupervisorHeartbeatRecord, SupervisorState, Task, TaskCheckpoint, TaskEvent, TaskSummary,
-    UpdateChainRequest, UpdateContractDefinitionRequest, UpdateContractRequest, UpdateFileRequest,
-    UpdateTaskRequest, UpdateTemplateRequest,
+    ChainGraphResponse, ChainRepository, ChainSummary, ChainWithContracts, CheckpointPatch,
+    CheckpointPatchInfo, Contract, ContractChatConversation, ContractChatMessageRecord,
+    ContractEvent, ContractRepository, ContractSummary, ContractTypeTemplateRecord,
+    ConversationMessage, ConversationSnapshot, CreateChainRequest, CreateContractRequest,
+    CreateFileRequest, CreateTaskRequest, CreateTemplateRequest, Daemon, DaemonTaskAssignment,
+    DaemonWithCapacity, DeliverableDefinition, File, FileSummary, FileVersion, HistoryEvent,
+    HistoryQueryFilters, MeshChatConversation, MeshChatMessageRecord, PhaseChangeResult,
+    PhaseConfig, PhaseDefinition, SupervisorHeartbeatRecord, SupervisorState, Task, TaskCheckpoint,
+    TaskEvent, TaskSummary, UpdateChainRequest, UpdateContractDefinitionRequest,
+    UpdateContractRequest, UpdateFileRequest, UpdateTaskRequest, UpdateTemplateRequest,
 };
 
 /// Repository error types.
@@ -4917,16 +4917,14 @@ pub async fn create_chain_for_owner(
 
     sqlx::query_as::<_, Chain>(
         r#"
-        INSERT INTO chains (owner_id, name, description, repository_url, local_path, loop_enabled, loop_max_iterations, loop_progress_check)
-        VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+        INSERT INTO chains (owner_id, name, description, loop_enabled, loop_max_iterations, loop_progress_check)
+        VALUES ($1, $2, $3, $4, $5, $6)
         RETURNING *
         "#,
     )
     .bind(owner_id)
     .bind(&req.name)
     .bind(&req.description)
-    .bind(&req.repository_url)
-    .bind(&req.local_path)
     .bind(loop_enabled)
     .bind(loop_max_iterations)
     .bind(&req.loop_progress_check)
@@ -5181,12 +5179,165 @@ pub async fn get_chain_with_contracts(
     match chain {
         Some(chain) => {
             let contracts = list_chain_contracts(pool, chain_id).await?;
-            Ok(Some(ChainWithContracts { chain, contracts }))
+            let repositories = list_chain_repositories(pool, chain_id).await?;
+            Ok(Some(ChainWithContracts {
+                chain,
+                contracts,
+                repositories,
+            }))
         }
         None => Ok(None),
     }
 }
 
+// =============================================================================
+// Chain Repository Operations
+// =============================================================================
+
+/// List all repositories for a chain.
+pub async fn list_chain_repositories(
+    pool: &PgPool,
+    chain_id: Uuid,
+) -> Result<Vec<ChainRepository>, sqlx::Error> {
+    sqlx::query_as::<_, ChainRepository>(
+        r#"
+        SELECT *
+        FROM chain_repositories
+        WHERE chain_id = $1
+        ORDER BY is_primary DESC, created_at ASC
+        "#,
+    )
+    .bind(chain_id)
+    .fetch_all(pool)
+    .await
+}
+
+/// Get a chain repository by ID.
+pub async fn get_chain_repository(
+    pool: &PgPool,
+    chain_id: Uuid,
+    repository_id: Uuid,
+) -> Result<Option<ChainRepository>, sqlx::Error> {
+    sqlx::query_as::<_, ChainRepository>(
+        r#"
+        SELECT *
+        FROM chain_repositories
+        WHERE id = $1 AND chain_id = $2
+        "#,
+    )
+    .bind(repository_id)
+    .bind(chain_id)
+    .fetch_optional(pool)
+    .await
+}
+
+/// Add a repository to a chain.
+pub async fn add_chain_repository(
+    pool: &PgPool,
+    chain_id: Uuid,
+    req: &AddChainRepositoryRequest,
+) -> Result<ChainRepository, sqlx::Error> {
+    // If is_primary, clear other primaries first
+    if req.is_primary {
+        sqlx::query(
+            r#"
+            UPDATE chain_repositories
+            SET is_primary = false, updated_at = NOW()
+            WHERE chain_id = $1 AND is_primary = true
+            "#,
+        )
+        .bind(chain_id)
+        .execute(pool)
+        .await?;
+    }
+
+    sqlx::query_as::<_, ChainRepository>(
+        r#"
+        INSERT INTO chain_repositories (chain_id, name, repository_url, local_path, source_type, status, is_primary)
+        VALUES ($1, $2, $3, $4, $5, 'ready', $6)
+        RETURNING *
+        "#,
+    )
+    .bind(chain_id)
+    .bind(&req.name)
+    .bind(&req.repository_url)
+    .bind(&req.local_path)
+    .bind(&req.source_type)
+    .bind(req.is_primary)
+    .fetch_one(pool)
+    .await
+}
+
+/// Delete a repository from a chain.
+pub async fn delete_chain_repository(
+    pool: &PgPool,
+    chain_id: Uuid,
+    repository_id: Uuid,
+) -> Result<bool, sqlx::Error> {
+    let result = sqlx::query(
+        r#"
+        DELETE FROM chain_repositories
+        WHERE id = $1 AND chain_id = $2
+        "#,
+    )
+    .bind(repository_id)
+    .bind(chain_id)
+    .execute(pool)
+    .await?;
+
+    Ok(result.rows_affected() > 0)
+}
+
+/// Set a repository as primary for a chain.
+pub async fn set_chain_repository_primary(
+    pool: &PgPool,
+    chain_id: Uuid,
+    repository_id: Uuid,
+) -> Result<ChainRepository, sqlx::Error> {
+    // Clear existing primary
+    sqlx::query(
+        r#"
+        UPDATE chain_repositories
+        SET is_primary = false, updated_at = NOW()
+        WHERE chain_id = $1 AND is_primary = true
+        "#,
+    )
+    .bind(chain_id)
+    .execute(pool)
+    .await?;
+
+    // Set new primary
+    sqlx::query_as::<_, ChainRepository>(
+        r#"
+        UPDATE chain_repositories
+        SET is_primary = true, updated_at = NOW()
+        WHERE id = $1 AND chain_id = $2
+        RETURNING *
+        "#,
+    )
+    .bind(repository_id)
+    .bind(chain_id)
+    .fetch_one(pool)
+    .await
+}
+
+/// Get the primary repository for a chain.
+pub async fn get_chain_primary_repository(
+    pool: &PgPool,
+    chain_id: Uuid,
+) -> Result<Option<ChainRepository>, sqlx::Error> {
+    sqlx::query_as::<_, ChainRepository>(
+        r#"
+        SELECT *
+        FROM chain_repositories
+        WHERE chain_id = $1 AND is_primary = true
+        "#,
+    )
+    .bind(chain_id)
+    .fetch_optional(pool)
+    .await
+}
+
 /// Get chain graph structure for visualization.
 pub async fn get_chain_graph(
     pool: &PgPool,
@@ -5381,6 +5532,7 @@ pub async fn get_chain_editor_data(
     match chain {
         Some(chain) => {
             let contracts = list_chain_contracts(pool, chain_id).await?;
+            let repositories = list_chain_repositories(pool, chain_id).await?;
 
             // Build nodes
             let nodes: Vec<ChainEditorNode> = contracts
@@ -5415,8 +5567,7 @@ pub async fn get_chain_editor_data(
                 id: Some(chain.id),
                 name: chain.name,
                 description: chain.description,
-                repository_url: chain.repository_url,
-                local_path: chain.local_path,
+                repositories,
                 loop_enabled: chain.loop_enabled,
                 loop_max_iterations: chain.loop_max_iterations,
                 loop_progress_check: chain.loop_progress_check,
diff --git a/makima/src/server/handlers/chains.rs b/makima/src/server/handlers/chains.rs
index 6cef72c..9b32495 100644
--- a/makima/src/server/handlers/chains.rs
+++ b/makima/src/server/handlers/chains.rs
@@ -13,10 +13,10 @@ use utoipa::ToSchema;
 use uuid::Uuid;
 
 use crate::db::models::{
-    AddContractDefinitionRequest, ChainContractDefinition, ChainContractDetail,
-    ChainDefinitionGraphResponse, ChainEditorData, ChainEvent, ChainGraphResponse, ChainSummary,
-    ChainWithContracts, CreateChainRequest, StartChainRequest, StartChainResponse,
-    UpdateChainRequest, UpdateContractDefinitionRequest,
+    AddChainRepositoryRequest, AddContractDefinitionRequest, ChainContractDefinition,
+    ChainContractDetail, ChainDefinitionGraphResponse, ChainEditorData, ChainEvent,
+    ChainGraphResponse, ChainRepository, ChainSummary, ChainWithContracts, CreateChainRequest,
+    StartChainRequest, StartChainResponse, UpdateChainRequest, UpdateContractDefinitionRequest,
 };
 use crate::db::repository::{self, RepositoryError};
 use crate::server::auth::Authenticated;
@@ -1255,3 +1255,330 @@ pub async fn stop_chain(
         }
     }
 }
+
+// =============================================================================
+// Chain Repository Handlers
+// =============================================================================
+
+/// List repositories for a chain.
+///
+/// GET /api/v1/chains/{id}/repositories
+#[utoipa::path(
+    get,
+    path = "/api/v1/chains/{id}/repositories",
+    params(
+        ("id" = Uuid, Path, description = "Chain ID")
+    ),
+    responses(
+        (status = 200, description = "List of repositories", body = Vec<ChainRepository>),
+        (status = 401, description = "Unauthorized", body = ApiError),
+        (status = 404, description = "Chain not found", body = ApiError),
+        (status = 503, description = "Database not configured", body = ApiError),
+        (status = 500, description = "Internal server error", body = ApiError)
+    ),
+    security(
+        ("bearer_auth" = []),
+        ("api_key" = [])
+    ),
+    tag = "Chains"
+)]
+pub async fn list_chain_repositories(
+    State(state): State<SharedState>,
+    Authenticated(auth): Authenticated,
+    Path(chain_id): Path<Uuid>,
+) -> impl IntoResponse {
+    let Some(ref pool) = state.db_pool else {
+        return (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
+        )
+            .into_response();
+    };
+
+    // Verify ownership
+    match repository::get_chain_for_owner(pool, chain_id, auth.owner_id).await {
+        Ok(Some(_)) => {}
+        Ok(None) => {
+            return (
+                StatusCode::NOT_FOUND,
+                Json(ApiError::new("NOT_FOUND", "Chain not found")),
+            )
+                .into_response();
+        }
+        Err(e) => {
+            tracing::error!("Failed to verify chain ownership: {}", e);
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response();
+        }
+    }
+
+    match repository::list_chain_repositories(pool, chain_id).await {
+        Ok(repos) => Json(repos).into_response(),
+        Err(e) => {
+            tracing::error!("Failed to list chain repositories: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response()
+        }
+    }
+}
+
+/// Add a repository to a chain.
+///
+/// POST /api/v1/chains/{id}/repositories
+#[utoipa::path(
+    post,
+    path = "/api/v1/chains/{id}/repositories",
+    params(
+        ("id" = Uuid, Path, description = "Chain ID")
+    ),
+    request_body = AddChainRepositoryRequest,
+    responses(
+        (status = 201, description = "Repository added", body = ChainRepository),
+        (status = 400, description = "Invalid request", body = ApiError),
+        (status = 401, description = "Unauthorized", body = ApiError),
+        (status = 404, description = "Chain not found", body = ApiError),
+        (status = 503, description = "Database not configured", body = ApiError),
+        (status = 500, description = "Internal server error", body = ApiError)
+    ),
+    security(
+        ("bearer_auth" = []),
+        ("api_key" = [])
+    ),
+    tag = "Chains"
+)]
+pub async fn add_chain_repository(
+    State(state): State<SharedState>,
+    Authenticated(auth): Authenticated,
+    Path(chain_id): Path<Uuid>,
+    Json(req): Json<AddChainRepositoryRequest>,
+) -> impl IntoResponse {
+    let Some(ref pool) = state.db_pool else {
+        return (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
+        )
+            .into_response();
+    };
+
+    // Validate request
+    if req.name.trim().is_empty() {
+        return (
+            StatusCode::BAD_REQUEST,
+            Json(ApiError::new("VALIDATION_ERROR", "Repository name cannot be empty")),
+        )
+            .into_response();
+    }
+
+    // Must have either repository_url or local_path
+    if req.repository_url.is_none() && req.local_path.is_none() {
+        return (
+            StatusCode::BAD_REQUEST,
+            Json(ApiError::new(
+                "VALIDATION_ERROR",
+                "Repository must have either repository_url or local_path",
+            )),
+        )
+            .into_response();
+    }
+
+    // Verify ownership
+    match repository::get_chain_for_owner(pool, chain_id, auth.owner_id).await {
+        Ok(Some(_)) => {}
+        Ok(None) => {
+            return (
+                StatusCode::NOT_FOUND,
+                Json(ApiError::new("NOT_FOUND", "Chain not found")),
+            )
+                .into_response();
+        }
+        Err(e) => {
+            tracing::error!("Failed to verify chain ownership: {}", e);
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response();
+        }
+    }
+
+    match repository::add_chain_repository(pool, chain_id, &req).await {
+        Ok(repo) => (StatusCode::CREATED, Json(repo)).into_response(),
+        Err(e) => {
+            tracing::error!("Failed to add chain repository: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response()
+        }
+    }
+}
+
+/// Delete a repository from a chain.
+///
+/// DELETE /api/v1/chains/{chain_id}/repositories/{repository_id}
+#[utoipa::path(
+    delete,
+    path = "/api/v1/chains/{chain_id}/repositories/{repository_id}",
+    params(
+        ("chain_id" = Uuid, Path, description = "Chain ID"),
+        ("repository_id" = Uuid, Path, description = "Repository ID")
+    ),
+    responses(
+        (status = 200, description = "Repository deleted"),
+        (status = 401, description = "Unauthorized", body = ApiError),
+        (status = 404, description = "Chain or repository not found", body = ApiError),
+        (status = 503, description = "Database not configured", body = ApiError),
+        (status = 500, description = "Internal server error", body = ApiError)
+    ),
+    security(
+        ("bearer_auth" = []),
+        ("api_key" = [])
+    ),
+    tag = "Chains"
+)]
+pub async fn delete_chain_repository(
+    State(state): State<SharedState>,
+    Authenticated(auth): Authenticated,
+    Path((chain_id, repository_id)): Path<(Uuid, Uuid)>,
+) -> impl IntoResponse {
+    let Some(ref pool) = state.db_pool else {
+        return (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
+        )
+            .into_response();
+    };
+
+    // Verify ownership
+    match repository::get_chain_for_owner(pool, chain_id, auth.owner_id).await {
+        Ok(Some(_)) => {}
+        Ok(None) => {
+            return (
+                StatusCode::NOT_FOUND,
+                Json(ApiError::new("NOT_FOUND", "Chain not found")),
+            )
+                .into_response();
+        }
+        Err(e) => {
+            tracing::error!("Failed to verify chain ownership: {}", e);
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response();
+        }
+    }
+
+    match repository::delete_chain_repository(pool, chain_id, repository_id).await {
+        Ok(true) => Json(serde_json::json!({"deleted": true})).into_response(),
+        Ok(false) => (
+            StatusCode::NOT_FOUND,
+            Json(ApiError::new("NOT_FOUND", "Repository not found")),
+        )
+            .into_response(),
+        Err(e) => {
+            tracing::error!("Failed to delete chain repository: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response()
+        }
+    }
+}
+
+/// Set a repository as primary for a chain.
+///
+/// PUT /api/v1/chains/{chain_id}/repositories/{repository_id}/primary
+#[utoipa::path(
+    put,
+    path = "/api/v1/chains/{chain_id}/repositories/{repository_id}/primary",
+    params(
+        ("chain_id" = Uuid, Path, description = "Chain ID"),
+        ("repository_id" = Uuid, Path, description = "Repository ID")
+    ),
+    responses(
+        (status = 200, description = "Repository set as primary", body = ChainRepository),
+        (status = 401, description = "Unauthorized", body = ApiError),
+        (status = 404, description = "Chain or repository not found", body = ApiError),
+        (status = 503, description = "Database not configured", body = ApiError),
+        (status = 500, description = "Internal server error", body = ApiError)
+    ),
+    security(
+        ("bearer_auth" = []),
+        ("api_key" = [])
+    ),
+    tag = "Chains"
+)]
+pub async fn set_chain_repository_primary(
+    State(state): State<SharedState>,
+    Authenticated(auth): Authenticated,
+    Path((chain_id, repository_id)): Path<(Uuid, Uuid)>,
+) -> impl IntoResponse {
+    let Some(ref pool) = state.db_pool else {
+        return (
+            StatusCode::SERVICE_UNAVAILABLE,
+            Json(ApiError::new("DB_UNAVAILABLE", "Database not configured")),
+        )
+            .into_response();
+    };
+
+    // Verify ownership
+    match repository::get_chain_for_owner(pool, chain_id, auth.owner_id).await {
+        Ok(Some(_)) => {}
+        Ok(None) => {
+            return (
+                StatusCode::NOT_FOUND,
+                Json(ApiError::new("NOT_FOUND", "Chain not found")),
+            )
+                .into_response();
+        }
+        Err(e) => {
+            tracing::error!("Failed to verify chain ownership: {}", e);
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response();
+        }
+    }
+
+    // Verify repository exists for this chain
+    match repository::get_chain_repository(pool, chain_id, repository_id).await {
+        Ok(Some(_)) => {}
+        Ok(None) => {
+            return (
+                StatusCode::NOT_FOUND,
+                Json(ApiError::new("NOT_FOUND", "Repository not found")),
+            )
+                .into_response();
+        }
+        Err(e) => {
+            tracing::error!("Failed to get chain repository: {}", e);
+            return (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response();
+        }
+    }
+
+    match repository::set_chain_repository_primary(pool, chain_id, repository_id).await {
+        Ok(repo) => Json(repo).into_response(),
+        Err(e) => {
+            tracing::error!("Failed to set chain repository as primary: {}", e);
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json(ApiError::new("DB_ERROR", e.to_string())),
+            )
+                .into_response()
+        }
+    }
+}
diff --git a/makima/src/server/mod.rs b/makima/src/server/mod.rs
index 5dde099..f6d2eda 100644
--- a/makima/src/server/mod.rs
+++ b/makima/src/server/mod.rs
@@ -245,6 +245,19 @@ pub fn make_router(state: SharedState) -> Router {
         // Chain control
         .route("/chains/{id}/start", post(chains::start_chain))
         .route("/chains/{id}/stop", post(chains::stop_chain))
+        // Chain repositories
+        .route(
+            "/chains/{id}/repositories",
+            get(chains::list_chain_repositories).post(chains::add_chain_repository),
+        )
+        .route(
+            "/chains/{chain_id}/repositories/{repository_id}",
+            axum::routing::delete(chains::delete_chain_repository),
+        )
+        .route(
+            "/chains/{chain_id}/repositories/{repository_id}/primary",
+            put(chains::set_chain_repository_primary),
+        )
         // Contract type templates (built-in only)
         .route("/contract-types", get(templates::list_contract_types))
         // Settings endpoints