feat: projects as backend sources with system prompt injection (#8739)

Signed-off-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/sdk/src/generated/types.gen.ts

@@ -752,12 +752,24 @@ export type CreateSourceRequest = {
      * Absolute path to the project root. Required when `global` is false.
      */
     projectDir?: string | null;
+    /**
+     * Project source ID. When set with `global: false`, the backend resolves
+     * the project's first working directory automatically. Takes precedence
+     * over `project_dir`.
+     */
+    projectId?: string | null;
+    /**
+     * Arbitrary key/value metadata.
+     */
+    properties?: {
+        [key: string]: unknown;
+    };
 };
 
 /**
  * The type of source entity.
  */
-export type SourceType = 'skill' | 'builtinSkill' | 'recipe' | 'subrecipe' | 'agent';
+export type SourceType = 'skill' | 'builtinSkill' | 'recipe' | 'subrecipe' | 'agent' | 'project';
 
 export type CreateSourceResponse = {
     source: SourceEntry;
@@ -774,11 +786,12 @@ export type SourceEntry = {
     description: string;
     content: string;
     /**
-     * Absolute path to the source on disk. A directory for skills, a file for
-     * recipes and agents. Built-in skills use read-only synthetic
-     * `builtin://skills/<name>` paths.
+     * Stable on-disk path identifying this source. Pass it back to
+     * update/delete/export to operate on this entry. Skills use the directory
+     * containing `SKILL.md`; projects use the project file path; built-in
+     * skills use `builtin://skills/<name>` synthetic paths.
      */
-    directory: string;
+    path: string;
     /**
      * True when the source lives in the user's global sources directory; false
      * when it lives inside a specific project.
@@ -789,6 +802,13 @@ export type SourceEntry = {
      * Only skills currently populate this; empty for other source types.
      */
     supportingFiles?: Array<string>;
+    /**
+     * Arbitrary key/value pairs for type-specific metadata (e.g. icon, color,
+     * preferredProvider for projects). Stored in the frontmatter.
+     */
+    properties?: {
+        [key: string]: unknown;
+    };
 };
 
 /**
@@ -802,6 +822,11 @@ export type SourceEntry = {
 export type ListSourcesRequest = {
     type?: SourceType | null;
     projectDir?: string | null;
+    /**
+     * When true, also scan the working directories of all known projects for
+     * project-scoped sources (e.g. skills stored under `{workingDir}/.agents/skills/`).
+     */
+    includeProjectSources?: boolean;
 };
 
 export type ListSourcesResponse = {
@@ -817,6 +842,16 @@ export type UpdateSourceRequest = {
     name: string;
     description: string;
     content: string;
+    /**
+     * When `Some`, replaces all stored properties on the source. When
+     * `None` (or omitted), the source's existing properties are
+     * preserved. Callers that don't model the full property bag (e.g.
+     * the skills editor, which only edits name/description/content)
+     * should omit this so per-skill metadata isn't silently erased.
+     */
+    properties?: {
+        [key: string]: unknown;
+    } | null;
 };
 
 export type UpdateSourceResponse = {

ui/sdk/src/generated/zod.gen.ts

@@ -755,7 +755,8 @@ export const zSourceType = z.enum([
     'builtinSkill',
     'recipe',
     'subrecipe',
-    'agent'
+    'agent',
+    'project'
 ]);
 
 /**
@@ -770,7 +771,12 @@ export const zCreateSourceRequest = z.object({
     projectDir: z.union([
         z.string(),
         z.null()
-    ]).optional()
+    ]).optional(),
+    projectId: z.union([
+        z.string(),
+        z.null()
+    ]).optional(),
+    properties: z.record(z.unknown()).optional()
 });
 
 /**
@@ -783,9 +789,10 @@ export const zSourceEntry = z.object({
     name: z.string(),
     description: z.string(),
     content: z.string(),
-    directory: z.string(),
+    path: z.string(),
     global: z.boolean(),
-    supportingFiles: z.array(z.string()).optional()
+    supportingFiles: z.array(z.string()).optional(),
+    properties: z.record(z.unknown()).optional()
 });
 
 export const zCreateSourceResponse = z.object({
@@ -808,7 +815,8 @@ export const zListSourcesRequest = z.object({
     projectDir: z.union([
         z.string(),
         z.null()
-    ]).optional()
+    ]).optional(),
+    includeProjectSources: z.boolean().optional().default(false)
 });
 
 export const zListSourcesResponse = z.object({
@@ -823,7 +831,11 @@ export const zUpdateSourceRequest = z.object({
     path: z.string(),
     name: z.string(),
     description: z.string(),
-    content: z.string()
+    content: z.string(),
+    properties: z.union([
+        z.record(z.unknown()),
+        z.null()
+    ]).optional()
 });
 
 export const zUpdateSourceResponse = z.object({