Make local graph execution optional across composed packages

src/capability-language/execution-scaffold.ts

@@ -5,6 +5,7 @@ import type { StructuralRequest } from "./structural-plan.js";
 import { parseQx, walkSyntax } from "./source.js";
 import { addImplementation } from "./implementation-edit.js";
 import { formatQuixosLock } from "../resource-lock/index.js";
+import { javascriptTarget } from "../execution-world/native-backends.js";
 const json = (value: unknown) => JSON.stringify(value, null, 2) + "\n";
 const q = (value: string) => JSON.stringify(value);
 const nixString = (value: string) => q(value).replaceAll("${", "\\${");
@@ -31,7 +32,10 @@ export async function executionScaffold(
   const create = (file: string, content: string) => files.push({ file: prefix + file, create: content });
   if (command === "package") {
     if (!spec.tools || !spec.revision) throw new Error("Execution package requires exact tool sources and a revision");
-    create("package.qx", `package ${spec.name} id ${q(spec.id)} revision ${q(spec.revision)} {\n}\n`);
+    create(
+      "package.qx",
+      `symbol JavaScript id ${q(javascriptTarget)};\npackage ${spec.name} id ${q(spec.id)} revision ${q(spec.revision)} {\n}\n`,
+    );
     create(
       "quixos.lock",
       formatQuixosLock({ formatVersion: 1, quixos: { resolver: "git", ...spec.tools.quixos }, resources: [] }),
@@ -90,7 +94,7 @@ in camino.assembleCaminoPackage {
     pkgs.lib.optional (portable != []) (camino.mkCaminoTypeScriptPackage {
       inherit pkgs context dependencies; src = ./.;
       entry = "src/server.ts"; entries.browser = "src/browser.ts";
-      targets = pkgs.lib.unique (pkgs.lib.concatMap (entry: entry.execution.targets) portable);
+      targets = pkgs.lib.unique (map (target: if target == "target:org.quixos.execution.javascript@1" then "browser" else if target == "server" then "server" else throw "Unsupported TypeScript backend target") (pkgs.lib.concatMap (entry: entry.execution.targets) portable));
     }) ++ pkgs.lib.optional (remote != []) (camino.mkCaminoTypeScriptService {
       inherit pkgs context dependencies; src = ./.; entry = "src/remote.ts";
     }) ++ pkgs.lib.optional (modules != {}) (camino.mkCaminoReactPackage {
@@ -134,15 +138,16 @@ in camino.assembleCaminoPackage {
       .filter((token) => !token.trivia && token.start >= execution.start && token.end <= execution.end)
       .map((token) => token.text);
     const remote = tokens[1] === "remote";
-    const targets = remote
+    const declaredTargets = remote
       ? ["remote"]
       : [...walkSyntax(execution)].filter((node) => node.kind === "identifier").map(text);
+    const targets = declaredTargets.length ? declaredTargets : ["server"];
     if (
       !targets.length ||
       new Set(targets).size !== targets.length ||
-      targets.some((target) => !(remote ? ["remote"] : ["browser", "server"]).includes(target))
+      targets.some((target) => !(remote ? ["remote"] : ["JavaScript", "server"]).includes(target))
     )
-      throw new Error("Execution scaffold supports browser/server portable targets and remote service handlers");
+      throw new Error("This TypeScript scaffold supports the JavaScript target, server, and remote service handlers");
     const authored = await fs.readFile(path.join(root, prefix, "package.qx"), "utf8");
     const syntax = parseQx(authored);
     const packageNode = syntax.root.children.find((node) => node.kind === "packageResourceDecl");
@@ -174,7 +179,7 @@ in camino.assembleCaminoPackage {
       `import type { ${remote ? "Remote" : "Portable"}Implementation } from "../gen/${remote ? "remote" : "qx"}.js";\nexport const handler: ${remote ? "Remote" : "Portable"}Implementation[${q(spec.name)}] = async (_context) => { throw new Error(${q("Implement " + spec.name)}); };\n`,
     );
     for (const target of targets) {
-      const file = prefix + `src/${target}.ts`;
+      const file = prefix + `src/${target === "JavaScript" ? "browser" : target}.ts`;
       const before = await fs.readFile(path.join(root, file), "utf8");
       files.push({
         file,

src/capability-language/generated/QuixosCapability.tokens

@@ -42,120 +42,121 @@ REF=41
 FRAGMENT=42
 IMPORT=43
 EXTERNAL=44
-ATOM=45
-INTERFACE=46
-INTERFACES=47
-PACKAGE=48
-VALUE=49
-FIELD=50
-RELATION=51
-OPERATION=52
-FUNCTION=53
-CONSTRUCTOR=54
-CONSTRUCTS=55
-INPUT=56
-CONFORM=57
-AS=58
-BIND=59
-STATIC=60
-TO=61
-PRIVATE=62
-SHARED=63
-STATE=64
-EDGE=65
-PROJECTION=66
-WITH=67
-USING=68
-ACCEPT=69
-VIA=70
-MATERIALIZE=71
-IF=72
-ABSENT=73
-ON=74
-POLICY=75
-DEFAULT=76
-SOURCE=77
-REPOSITORY=78
-COMMIT=79
-REVISION=80
-SEMANTIC_MAJOR=81
-ON_DELETE=82
-LIFECYCLE=83
-JOURNAL=84
-SUBSCRIPTION=85
-RETAIN_OTHER=86
-KEYED=87
-PUBLIC_TRAVERSAL=88
-ID=89
-DOC=90
-MODE=91
-EMITS=92
-RECEIVER=93
-REQUIRES=94
-ANY=95
-GET=96
-SET=97
-WATCH=98
-START=99
-STOP=100
-READ=101
-WRITE=102
-RESOLVE=103
-CONNECT=104
-DISCONNECT=105
-CALL=106
-WATCH_START=107
-WATCH_STOP=108
-SUBSCRIBE=109
-UNSUBSCRIBE=110
-REGISTER=111
-CRDT=112
-OPTIONAL_ONE=113
-EXACTLY_ONE=114
-MANY_UNIQUE=115
-MANY=116
-ORDERED=117
-UNIT=118
-WATCH_HANDLE=119
-MESSAGE=120
-ATOM_REF=121
-INTERFACE_REF=122
-OPTIONAL=123
-LIST=124
-RECORD=125
-BOOL=126
-BYTES=127
-DOUBLE=128
-INT32=129
-INT64=130
-STRING=131
-UINT32=132
-UINT64=133
-TRUE=134
-FALSE=135
-NULL=136
-ARROW=137
-COLON=138
-SEMI=139
-COMMA=140
-DOT=141
-LBRACE=142
-RBRACE=143
-LBRACK=144
-RBRACK=145
-LPAREN=146
-RPAREN=147
-LT=148
-GT=149
-AMP=150
-EQUAL=151
-INTEGER=152
-JSON_NUMBER=153
-IDENTIFIER=154
-STRING_LITERAL=155
-LINE_COMMENT=156
-BLOCK_COMMENT=157
-WS=158
+SYMBOL=45
+ATOM=46
+INTERFACE=47
+INTERFACES=48
+PACKAGE=49
+VALUE=50
+FIELD=51
+RELATION=52
+OPERATION=53
+FUNCTION=54
+CONSTRUCTOR=55
+CONSTRUCTS=56
+INPUT=57
+CONFORM=58
+AS=59
+BIND=60
+STATIC=61
+TO=62
+PRIVATE=63
+SHARED=64
+STATE=65
+EDGE=66
+PROJECTION=67
+WITH=68
+USING=69
+ACCEPT=70
+VIA=71
+MATERIALIZE=72
+IF=73
+ABSENT=74
+ON=75
+POLICY=76
+DEFAULT=77
+SOURCE=78
+REPOSITORY=79
+COMMIT=80
+REVISION=81
+SEMANTIC_MAJOR=82
+ON_DELETE=83
+LIFECYCLE=84
+JOURNAL=85
+SUBSCRIPTION=86
+RETAIN_OTHER=87
+KEYED=88
+PUBLIC_TRAVERSAL=89
+ID=90
+DOC=91
+MODE=92
+EMITS=93
+RECEIVER=94
+REQUIRES=95
+ANY=96
+GET=97
+SET=98
+WATCH=99
+START=100
+STOP=101
+READ=102
+WRITE=103
+RESOLVE=104
+CONNECT=105
+DISCONNECT=106
+CALL=107
+WATCH_START=108
+WATCH_STOP=109
+SUBSCRIBE=110
+UNSUBSCRIBE=111
+REGISTER=112
+CRDT=113
+OPTIONAL_ONE=114
+EXACTLY_ONE=115
+MANY_UNIQUE=116
+MANY=117
+ORDERED=118
+UNIT=119
+WATCH_HANDLE=120
+MESSAGE=121
+ATOM_REF=122
+INTERFACE_REF=123
+OPTIONAL=124
+LIST=125
+RECORD=126
+BOOL=127
+BYTES=128
+DOUBLE=129
+INT32=130
+INT64=131
+STRING=132
+UINT32=133
+UINT64=134
+TRUE=135
+FALSE=136
+NULL=137
+ARROW=138
+COLON=139
+SEMI=140
+COMMA=141
+DOT=142
+LBRACE=143
+RBRACE=144
+LBRACK=145
+RBRACK=146
+LPAREN=147
+RPAREN=148
+LT=149
+GT=150
+AMP=151
+EQUAL=152
+INTEGER=153
+JSON_NUMBER=154
+IDENTIFIER=155
+STRING_LITERAL=156
+LINE_COMMENT=157
+BLOCK_COMMENT=158
+WS=159
 'edit'=1
 'module'=2
 'contract'=3
@@ -200,110 +201,111 @@ WS=158
 'fragment'=42
 'import'=43
 'external'=44
-'atom'=45
-'interface'=46
-'interfaces'=47
-'package'=48
-'value'=49
-'field'=50
-'relation'=51
-'operation'=52
-'function'=53
-'constructor'=54
-'constructs'=55
-'input'=56
-'conform'=57
-'as'=58
-'bind'=59
-'static'=60
-'to'=61
-'private'=62
-'shared'=63
-'state'=64
-'edge'=65
-'projection'=66
-'with'=67
-'using'=68
-'accept'=69
-'via'=70
-'materialize'=71
-'if'=72
-'absent'=73
-'on'=74
-'policy'=75
-'default'=76
-'source'=77
-'repository'=78
-'commit'=79
-'revision'=80
-'semantic-major'=81
-'on-delete'=82
-'lifecycle'=83
-'journal'=84
-'subscription'=85
-'retain-other'=86
-'keyed'=87
-'public-traversal'=88
-'id'=89
-'doc'=90
-'mode'=91
-'emits'=92
-'receiver'=93
-'requires'=94
-'any'=95
-'get'=96
-'set'=97
-'watch'=98
-'start'=99
-'stop'=100
-'read'=101
-'write'=102
-'resolve'=103
-'connect'=104
-'disconnect'=105
-'call'=106
-'watch-start'=107
-'watch-stop'=108
-'subscribe'=109
-'unsubscribe'=110
-'register'=111
-'crdt'=112
-'optional-one'=113
-'exactly-one'=114
-'many-unique'=115
-'many'=116
-'ordered'=117
-'unit'=118
-'watch-handle'=119
-'message'=120
-'atom-ref'=121
-'interface-ref'=122
-'optional'=123
-'list'=124
-'record'=125
-'bool'=126
-'bytes'=127
-'double'=128
-'int32'=129
-'int64'=130
-'string'=131
-'uint32'=132
-'uint64'=133
-'true'=134
-'false'=135
-'null'=136
-'->'=137
-':'=138
-';'=139
-','=140
-'.'=141
-'{'=142
-'}'=143
-'['=144
-']'=145
-'('=146
-')'=147
-'<'=148
-'>'=149
-'&'=150
-'='=151
+'symbol'=45
+'atom'=46
+'interface'=47
+'interfaces'=48
+'package'=49
+'value'=50
+'field'=51
+'relation'=52
+'operation'=53
+'function'=54
+'constructor'=55
+'constructs'=56
+'input'=57
+'conform'=58
+'as'=59
+'bind'=60
+'static'=61
+'to'=62
+'private'=63
+'shared'=64
+'state'=65
+'edge'=66
+'projection'=67
+'with'=68
+'using'=69
+'accept'=70
+'via'=71
+'materialize'=72
+'if'=73
+'absent'=74
+'on'=75
+'policy'=76
+'default'=77
+'source'=78
+'repository'=79
+'commit'=80
+'revision'=81
+'semantic-major'=82
+'on-delete'=83
+'lifecycle'=84
+'journal'=85
+'subscription'=86
+'retain-other'=87
+'keyed'=88
+'public-traversal'=89
+'id'=90
+'doc'=91
+'mode'=92
+'emits'=93
+'receiver'=94
+'requires'=95
+'any'=96
+'get'=97
+'set'=98
+'watch'=99
+'start'=100
+'stop'=101
+'read'=102
+'write'=103
+'resolve'=104
+'connect'=105
+'disconnect'=106
+'call'=107
+'watch-start'=108
+'watch-stop'=109
+'subscribe'=110
+'unsubscribe'=111
+'register'=112
+'crdt'=113
+'optional-one'=114
+'exactly-one'=115
+'many-unique'=116
+'many'=117
+'ordered'=118
+'unit'=119
+'watch-handle'=120
+'message'=121
+'atom-ref'=122
+'interface-ref'=123
+'optional'=124
+'list'=125
+'record'=126
+'bool'=127
+'bytes'=128
+'double'=129
+'int32'=130
+'int64'=131
+'string'=132
+'uint32'=133
+'uint64'=134
+'true'=135
+'false'=136
+'null'=137
+'->'=138
+':'=139
+';'=140
+','=141
+'.'=142
+'{'=143
+'}'=144
+'['=145
+']'=146
+'('=147
+')'=148
+'<'=149
+'>'=150
+'&'=151
+'='=152

src/capability-language/generated/QuixosCapabilityLexer.tokens

@@ -42,120 +42,121 @@ REF=41
 FRAGMENT=42
 IMPORT=43
 EXTERNAL=44
-ATOM=45
-INTERFACE=46
-INTERFACES=47
-PACKAGE=48
-VALUE=49
-FIELD=50
-RELATION=51
-OPERATION=52
-FUNCTION=53
-CONSTRUCTOR=54
-CONSTRUCTS=55
-INPUT=56
-CONFORM=57
-AS=58
-BIND=59
-STATIC=60
-TO=61
-PRIVATE=62
-SHARED=63
-STATE=64
-EDGE=65
-PROJECTION=66
-WITH=67
-USING=68
-ACCEPT=69
-VIA=70
-MATERIALIZE=71
-IF=72
-ABSENT=73
-ON=74
-POLICY=75
-DEFAULT=76
-SOURCE=77
-REPOSITORY=78
-COMMIT=79
-REVISION=80
-SEMANTIC_MAJOR=81
-ON_DELETE=82
-LIFECYCLE=83
-JOURNAL=84
-SUBSCRIPTION=85
-RETAIN_OTHER=86
-KEYED=87
-PUBLIC_TRAVERSAL=88
-ID=89
-DOC=90
-MODE=91
-EMITS=92
-RECEIVER=93
-REQUIRES=94
-ANY=95
-GET=96
-SET=97
-WATCH=98
-START=99
-STOP=100
-READ=101
-WRITE=102
-RESOLVE=103
-CONNECT=104
-DISCONNECT=105
-CALL=106
-WATCH_START=107
-WATCH_STOP=108
-SUBSCRIBE=109
-UNSUBSCRIBE=110
-REGISTER=111
-CRDT=112
-OPTIONAL_ONE=113
-EXACTLY_ONE=114
-MANY_UNIQUE=115
-MANY=116
-ORDERED=117
-UNIT=118
-WATCH_HANDLE=119
-MESSAGE=120
-ATOM_REF=121
-INTERFACE_REF=122
-OPTIONAL=123
-LIST=124
-RECORD=125
-BOOL=126
-BYTES=127
-DOUBLE=128
-INT32=129
-INT64=130
-STRING=131
-UINT32=132
-UINT64=133
-TRUE=134
-FALSE=135
-NULL=136
-ARROW=137
-COLON=138
-SEMI=139
-COMMA=140
-DOT=141
-LBRACE=142
-RBRACE=143
-LBRACK=144
-RBRACK=145
-LPAREN=146
-RPAREN=147
-LT=148
-GT=149
-AMP=150
-EQUAL=151
-INTEGER=152
-JSON_NUMBER=153
-IDENTIFIER=154
-STRING_LITERAL=155
-LINE_COMMENT=156
-BLOCK_COMMENT=157
-WS=158
+SYMBOL=45
+ATOM=46
+INTERFACE=47
+INTERFACES=48
+PACKAGE=49
+VALUE=50
+FIELD=51
+RELATION=52
+OPERATION=53
+FUNCTION=54
+CONSTRUCTOR=55
+CONSTRUCTS=56
+INPUT=57
+CONFORM=58
+AS=59
+BIND=60
+STATIC=61
+TO=62
+PRIVATE=63
+SHARED=64
+STATE=65
+EDGE=66
+PROJECTION=67
+WITH=68
+USING=69
+ACCEPT=70
+VIA=71
+MATERIALIZE=72
+IF=73
+ABSENT=74
+ON=75
+POLICY=76
+DEFAULT=77
+SOURCE=78
+REPOSITORY=79
+COMMIT=80
+REVISION=81
+SEMANTIC_MAJOR=82
+ON_DELETE=83
+LIFECYCLE=84
+JOURNAL=85
+SUBSCRIPTION=86
+RETAIN_OTHER=87
+KEYED=88
+PUBLIC_TRAVERSAL=89
+ID=90
+DOC=91
+MODE=92
+EMITS=93
+RECEIVER=94
+REQUIRES=95
+ANY=96
+GET=97
+SET=98
+WATCH=99
+START=100
+STOP=101
+READ=102
+WRITE=103
+RESOLVE=104
+CONNECT=105
+DISCONNECT=106
+CALL=107
+WATCH_START=108
+WATCH_STOP=109
+SUBSCRIBE=110
+UNSUBSCRIBE=111
+REGISTER=112
+CRDT=113
+OPTIONAL_ONE=114
+EXACTLY_ONE=115
+MANY_UNIQUE=116
+MANY=117
+ORDERED=118
+UNIT=119
+WATCH_HANDLE=120
+MESSAGE=121
+ATOM_REF=122
+INTERFACE_REF=123
+OPTIONAL=124
+LIST=125
+RECORD=126
+BOOL=127
+BYTES=128
+DOUBLE=129
+INT32=130
+INT64=131
+STRING=132
+UINT32=133
+UINT64=134
+TRUE=135
+FALSE=136
+NULL=137
+ARROW=138
+COLON=139
+SEMI=140
+COMMA=141
+DOT=142
+LBRACE=143
+RBRACE=144
+LBRACK=145
+RBRACK=146
+LPAREN=147
+RPAREN=148
+LT=149
+GT=150
+AMP=151
+EQUAL=152
+INTEGER=153
+JSON_NUMBER=154
+IDENTIFIER=155
+STRING_LITERAL=156
+LINE_COMMENT=157
+BLOCK_COMMENT=158
+WS=159
 'edit'=1
 'module'=2
 'contract'=3
@@ -200,110 +201,111 @@ WS=158
 'fragment'=42
 'import'=43
 'external'=44
-'atom'=45
-'interface'=46
-'interfaces'=47
-'package'=48
-'value'=49
-'field'=50
-'relation'=51
-'operation'=52
-'function'=53
-'constructor'=54
-'constructs'=55
-'input'=56
-'conform'=57
-'as'=58
-'bind'=59
-'static'=60
-'to'=61
-'private'=62
-'shared'=63
-'state'=64
-'edge'=65
-'projection'=66
-'with'=67
-'using'=68
-'accept'=69
-'via'=70
-'materialize'=71
-'if'=72
-'absent'=73
-'on'=74
-'policy'=75
-'default'=76
-'source'=77
-'repository'=78
-'commit'=79
-'revision'=80
-'semantic-major'=81
-'on-delete'=82
-'lifecycle'=83
-'journal'=84
-'subscription'=85
-'retain-other'=86
-'keyed'=87
-'public-traversal'=88
-'id'=89
-'doc'=90
-'mode'=91
-'emits'=92
-'receiver'=93
-'requires'=94
-'any'=95
-'get'=96
-'set'=97
-'watch'=98
-'start'=99
-'stop'=100
-'read'=101
-'write'=102
-'resolve'=103
-'connect'=104
-'disconnect'=105
-'call'=106
-'watch-start'=107
-'watch-stop'=108
-'subscribe'=109
-'unsubscribe'=110
-'register'=111
-'crdt'=112
-'optional-one'=113
-'exactly-one'=114
-'many-unique'=115
-'many'=116
-'ordered'=117
-'unit'=118
-'watch-handle'=119
-'message'=120
-'atom-ref'=121
-'interface-ref'=122
-'optional'=123
-'list'=124
-'record'=125
-'bool'=126
-'bytes'=127
-'double'=128
-'int32'=129
-'int64'=130
-'string'=131
-'uint32'=132
-'uint64'=133
-'true'=134
-'false'=135
-'null'=136
-'->'=137
-':'=138
-';'=139
-','=140
-'.'=141
-'{'=142
-'}'=143
-'['=144
-']'=145
-'('=146
-')'=147
-'<'=148
-'>'=149
-'&'=150
-'='=151
+'symbol'=45
+'atom'=46
+'interface'=47
+'interfaces'=48
+'package'=49
+'value'=50
+'field'=51
+'relation'=52
+'operation'=53
+'function'=54
+'constructor'=55
+'constructs'=56
+'input'=57
+'conform'=58
+'as'=59
+'bind'=60
+'static'=61
+'to'=62
+'private'=63
+'shared'=64
+'state'=65
+'edge'=66
+'projection'=67
+'with'=68
+'using'=69
+'accept'=70
+'via'=71
+'materialize'=72
+'if'=73
+'absent'=74
+'on'=75
+'policy'=76
+'default'=77
+'source'=78
+'repository'=79
+'commit'=80
+'revision'=81
+'semantic-major'=82
+'on-delete'=83
+'lifecycle'=84
+'journal'=85
+'subscription'=86
+'retain-other'=87
+'keyed'=88
+'public-traversal'=89
+'id'=90
+'doc'=91
+'mode'=92
+'emits'=93
+'receiver'=94
+'requires'=95
+'any'=96
+'get'=97
+'set'=98
+'watch'=99
+'start'=100
+'stop'=101
+'read'=102
+'write'=103
+'resolve'=104
+'connect'=105
+'disconnect'=106
+'call'=107
+'watch-start'=108
+'watch-stop'=109
+'subscribe'=110
+'unsubscribe'=111
+'register'=112
+'crdt'=113
+'optional-one'=114
+'exactly-one'=115
+'many-unique'=116
+'many'=117
+'ordered'=118
+'unit'=119
+'watch-handle'=120
+'message'=121
+'atom-ref'=122
+'interface-ref'=123
+'optional'=124
+'list'=125
+'record'=126
+'bool'=127
+'bytes'=128
+'double'=129
+'int32'=130
+'int64'=131
+'string'=132
+'uint32'=133
+'uint64'=134
+'true'=135
+'false'=136
+'null'=137
+'->'=138
+':'=139
+';'=140
+','=141
+'.'=142
+'{'=143
+'}'=144
+'['=145
+']'=146
+'('=147
+')'=148
+'<'=149
+'>'=150
+'&'=151
+'='=152

src/capability-language/generated/QuixosCapabilityVisitor.ts

@@ -10,6 +10,7 @@ import { WorkspaceItemContext } from "./QuixosCapabilityParser.js";
 import { ResourceImportDeclContext } from "./QuixosCapabilityParser.js";
 import { ExternalAtomDeclContext } from "./QuixosCapabilityParser.js";
 import { ExternalInterfaceDeclContext } from "./QuixosCapabilityParser.js";
+import { SymbolDeclContext } from "./QuixosCapabilityParser.js";
 import { ResourcePreambleContext } from "./QuixosCapabilityParser.js";
 import { AtomDeclContext } from "./QuixosCapabilityParser.js";
 import { InterfaceResourceDeclContext } from "./QuixosCapabilityParser.js";
@@ -145,6 +146,12 @@ export class QuixosCapabilityVisitor<Result> extends AbstractParseTreeVisitor<Re
      * @return the visitor result
      */
     visitExternalInterfaceDecl?: (ctx: ExternalInterfaceDeclContext) => Result;
+    /**
+     * Visit a parse tree produced by `QuixosCapabilityParser.symbolDecl`.
+     * @param ctx the parse tree
+     * @return the visitor result
+     */
+    visitSymbolDecl?: (ctx: SymbolDeclContext) => Result;
     /**
      * Visit a parse tree produced by `QuixosCapabilityParser.resourcePreamble`.
      * @param ctx the parse tree

src/capability-language/parser.ts

@@ -205,6 +205,7 @@ interface LoweringState {
   fileName: string;
   diagnostics: CapabilitySourceDiagnostic[];
   atoms: Map<string, AtomId>;
+  symbols: Map<string, string>;
   interfaces: Map<string, InterfaceSymbol>;
   packages: Map<string, PackageSymbol>;
   attachments: Map<string, AttachmentSymbol>;
@@ -387,14 +388,33 @@ const lowerSelectedOperations = (
   return { operations };
 };
 
-const lowerExecution = (context: ExecutionClauseContext | null): { execution?: ExecutionContract } => {
+const lowerExecution = (
+  state: LoweringState,
+  context: ExecutionClauseContext | null,
+  implementation = false,
+): { execution?: ExecutionContract } => {
   if (!context) return {};
+  if (!implementation && context.identifierList())
+    loweringIssue(
+      state,
+      context,
+      "interface-execution-targets",
+      "Interfaces declare effects; execution targets belong to package implementations",
+    );
+  const targets = context
+    .identifierList()
+    ?.identifier()
+    .map((node) => {
+      const name = identifier(node);
+      if (name === "server") return name;
+      return requireSymbol(state, state.symbols, name, node, "nominal execution target") ?? `unresolved:${name}`;
+    }) ?? ["server"];
   return {
     execution: context.REMOTE()
       ? { kind: "remote" }
       : {
           kind: context.SNAPSHOT() ? "snapshot" : "transaction",
-          targets: context.identifierList()!.identifier().map(identifier),
+          targets: implementation ? targets : ["server"],
         },
   };
 };
@@ -508,17 +528,17 @@ const lowerValueMember = (state: LoweringState, context: ValueMemberContext): In
     if (operation.GET()) {
       operations.push({
         ...valueOperation("get", capabilityId.operation(stringValue(operation.stringLiteral(0))), memberValueType),
-        ...lowerExecution(operation.executionClause()),
+        ...lowerExecution(state, operation.executionClause()),
       });
     } else if (operation.EDIT()) {
       operations.push({
         ...valueOperation("edit", capabilityId.operation(stringValue(operation.stringLiteral(0))), memberValueType),
-        ...lowerExecution(operation.executionClause()),
+        ...lowerExecution(state, operation.executionClause()),
       });
     } else if (operation.SET()) {
       operations.push({
         ...valueOperation("set", capabilityId.operation(stringValue(operation.stringLiteral(0))), memberValueType),
-        ...lowerExecution(operation.executionClause()),
+        ...lowerExecution(state, operation.executionClause()),
       });
     } else {
       operations.push(
@@ -611,7 +631,7 @@ const lowerRelationshipMember = (
       );
     }
     if (operation.executionClause())
-      Object.assign(operations[operations.length - 1]!, lowerExecution(operation.executionClause()));
+      Object.assign(operations[operations.length - 1]!, lowerExecution(state, operation.executionClause()));
   }
   return {
     kind: "relationship",
@@ -653,7 +673,7 @@ const lowerOperationMember = (state: LoweringState, context: OperationMemberCont
         outputType,
         mode: "call",
         ...(context.STATIC() ? { scope: "class" as const } : {}),
-        ...lowerExecution(context.executionClause()),
+        ...lowerExecution(state, context.executionClause()),
       },
     ],
   };
@@ -814,18 +834,24 @@ const lowerInterfaceTemplate = (
             const id = capabilityId.operation(stringValue(operation.stringLiteral(0)));
             if (operation.GET())
               return [
-                { ...signature("get", id, valueType.unit, type), ...lowerExecution(operation.executionClause()) },
+                {
+                  ...signature("get", id, valueType.unit, type),
+                  ...lowerExecution(state, operation.executionClause()),
+                },
               ];
             if (operation.EDIT())
               return [
                 {
                   ...signature("edit", id, { kind: "change", value: type }, valueType.unit),
-                  ...lowerExecution(operation.executionClause()),
+                  ...lowerExecution(state, operation.executionClause()),
                 },
               ];
             if (operation.SET())
               return [
-                { ...signature("set", id, type, valueType.unit), ...lowerExecution(operation.executionClause()) },
+                {
+                  ...signature("set", id, type, valueType.unit),
+                  ...lowerExecution(state, operation.executionClause()),
+                },
               ];
             return [
               signature("watch-start", id, valueType.unit, valueType.watchHandle, "watch-start", type),
@@ -859,7 +885,7 @@ const lowerInterfaceTemplate = (
                 outputType,
               ),
               ...(operation.STATIC() ? { scope: "class" as const } : {}),
-              ...lowerExecution(operation.executionClause()),
+              ...lowerExecution(state, operation.executionClause()),
             },
           ],
         };
@@ -907,7 +933,10 @@ const lowerInterfaceTemplate = (
           const id = capabilityId.operation(stringValue(operation.stringLiteral(0)));
           if (operation.RESOLVE())
             return [
-              { ...signature("resolve", id, valueType.unit, resolved), ...lowerExecution(operation.executionClause()) },
+              {
+                ...signature("resolve", id, valueType.unit, resolved),
+                ...lowerExecution(state, operation.executionClause()),
+              },
             ];
           if (operation.CONNECT() || operation.DISCONNECT())
             return [
@@ -918,7 +947,7 @@ const lowerInterfaceTemplate = (
                   operation.CONNECT() ? keyedTarget : targetType,
                   valueType.unit,
                 ),
-                ...lowerExecution(operation.executionClause()),
+                ...lowerExecution(state, operation.executionClause()),
               },
             ];
           return [
@@ -1196,7 +1225,7 @@ const lowerPackageOperation = (
     inputType: lowerValueType(state, context.valueType(0)),
     outputType: lowerValueType(state, context.valueType(1)),
     mode: text(context.operationMode()) as InterfaceOperationMode,
-    ...lowerExecution(context.executionClause()),
+    ...lowerExecution(state, context.executionClause(), true),
     eventType: event ? lowerValueType(state, event.valueType()) : undefined,
     receiverRequirement: lowerReceiver(state, context.receiverRequirement()),
     dependencyPorts: ports,
@@ -1213,7 +1242,7 @@ const lowerPackageFunction = (
   const alias = identifier(context.identifier());
   const entry: PackageExport = {
     kind: "function",
-    ...lowerExecution(context.executionClause()),
+    ...lowerExecution(state, context.executionClause(), true),
     id: capabilityId.packageExport(stringValue(context.stringLiteral())),
     displayName: alias,
     inputType: lowerValueType(state, context.valueType(0)),
@@ -1355,7 +1384,7 @@ const lowerGenericPackageExport = (
       displayName: identifier(context.identifier()),
       parameters,
       kind: operation ? "operation" : "function",
-      ...lowerExecution(context.executionClause()),
+      ...lowerExecution(state, context.executionClause(), true),
       inputType: state.types.expression(context.valueType(0)!),
       outputType: state.types.expression(context.valueType(1)!),
       dependencyPorts,
@@ -3092,6 +3121,7 @@ const newLoweringState = (fileName: string, diagnostics: CapabilitySourceDiagnos
     atoms,
     types: new GenericSourceTypes(atoms),
     interfaces: new Map(),
+    symbols: new Map(),
     packages: new Map(),
     attachments: new Map(),
   };
@@ -3240,6 +3270,20 @@ const compileCapabilityResourceSourceInternal = (
   const externalAtoms = externalAtomsFrom(state, preamble.atoms);
   const imports = registerImports(state, preamble.imports, environment);
   const externalInterfaces = externalInterfacesFrom(state, preamble.interfaces);
+  for (const declaration of (interfaceContext ?? packageContext)!
+    .resourcePreamble()
+    .flatMap((entry) => entry.symbolDecl() ?? [])) {
+    const name = identifier(declaration.identifier());
+    const identity = stringValue(declaration.stringLiteral());
+    if (name === "server" || identity === "server" || !identity.trim())
+      loweringIssue(
+        state,
+        declaration,
+        "invalid-symbol",
+        "Nominal symbols require a nonempty identity distinct from the server executor",
+      );
+    declareSymbol(state, state.symbols, name, identity, declaration, "symbol");
+  }
   state.types.declareAliases(preamble.aliases);
 
   let resource: CapabilityResource;