CB-634 (draft): mount the IDE Index MCP into a member, opt-in per profile

Adds `ideMcpUrl` to FleetConfig.Profile (default off). When set, the Claude Code launcher mounts the IDE Index MCP as a second inline --mcp-config server named `intellij`, and appends an IDE charter that pins every ide_* call to the member's own worktree (spec.cwd()). The charter order is role -> ide -> reply, one --append-system-prompt-file, reply last (CB-618). The mount gate now fires on ideMcpUrl alone, not only mcpUrl. ConfigRef treats an ideMcpUrl change as deferred, like the other launch flags. Never touches .mcp.json or CLAUDE.md — the mount and the rule arrive as launch flags, so a project's own config is untouched. Not yet done (see fleetd #162): the bridged-owned IDE lifecycle (open on provision, close before worktree removal), and the opencode adapter (separate ticket). fleetd.example.yaml documents ideMcpUrl and fixes the stale parityOverlay default. 911 tests green.
2026-08-23 16:00:36 +02:00
parent 3f4ac2b24e
commit d811b30df3
8 changed files with 168 additions and 19 deletions
@@ -276,6 +276,9 @@ public final class ConfigRef implements Supplier<FleetConfig> {
                && Objects.equals(a.workspace(), b.workspace())
                && Objects.equals(a.tabLabel(), b.tabLabel())
                && Objects.equals(a.mcpUrl(), b.mcpUrl())
+                // CB-634: the IDE MCP mount is a launch flag, fixed at spawn like mcpUrl — a
+                // reload changes it only for members spawned after, so a changed value is deferred.
+                && Objects.equals(a.ideMcpUrl(), b.ideMcpUrl())
                && Objects.equals(a.cwd(), b.cwd())
                && Objects.equals(a.parityOverlay(), b.parityOverlay())
                && Objects.equals(a.gitTokenEnv(), b.gitTokenEnv())
@@ -289,7 +289,8 @@ public record FleetConfig(
                         Integer maxLoad,
                         Boolean subscription,
                         String exhaustedPattern,
-                         String credentialId) {
+                         String credentialId,
+                         String ideMcpUrl) {

        /** Peer kind spawned by {@link dev.ltms.fleet.member.ClaudeCodeLauncher} (the default). */
        public static final String KIND_CLAUDE_CODE = "claude-code";
@@ -348,6 +349,10 @@ public record FleetConfig(
            // "quarantines alone" fallback actually lives, so today's behaviour needs no defaulting
            // here at all.
            credentialId = (credentialId == null || credentialId.isBlank()) ? null : credentialId;
+            // CB-634: opt-in per profile, default off. A URL, not a boolean — host and port are
+            // host-specific, mirroring mcpUrl. When set, the member gets the IDE Index MCP mounted
+            // (pinned to its own worktree via the charter). Blank ⇒ off.
+            ideMcpUrl = (ideMcpUrl == null || ideMcpUrl.isBlank()) ? null : ideMcpUrl;
        }

        /**
@@ -392,7 +397,7 @@ public record FleetConfig(
        public Profile withProfile(String p) {
            return new Profile(p, baseUrl, model, configDir, tokenEnv, argv, placement, workspace, tabLabel,
                    mcpUrl, cwd, parityOverlay, gitTokenEnv, gitHostEnv, kind, env, weight, maxLoad, subscription,
-                    exhaustedPattern, credentialId);
+                    exhaustedPattern, credentialId, ideMcpUrl);
        }

        /** True when this profile is served by the Claude Code adapter (the default kind). */
@@ -441,7 +446,7 @@ public record FleetConfig(
                      Boolean subscription, String exhaustedPattern) {
            this(profile, baseUrl, model, configDir, tokenEnv, argv, placement, workspace, tabLabel,
                    mcpUrl, cwd, parityOverlay, gitTokenEnv, gitHostEnv, kind, env, weight, maxLoad,
-                    subscription, exhaustedPattern, null);
+                    subscription, exhaustedPattern, null, null);
        }

        /** True when this profile's CB-578 stage A backend-exhausted classification is configured. */
@@ -489,6 +494,19 @@ public record FleetConfig(
            return mcpUrl != null && !mcpUrl.isBlank();
        }

+        /**
+         * True when the IDE Index MCP should be mounted into a spawned worker (CB-634), pinned to
+         * the worker's own worktree via the charter. Opt-in per profile, default off.
+         */
+        public boolean hasIdeMcp() {
+            return ideMcpUrl != null && !ideMcpUrl.isBlank();
+        }
+
+        /** True when this profile mounts any MCP server into its member — the bridge, the IDE, or both. */
+        public boolean mountsAnyMcp() {
+            return hasMcp() || hasIdeMcp();
+        }
+
        /**
         * Render this member's tab label (CB-557): {@code {role}}, {@code {profile}},
         * {@code {model}} and {@code {n}} are substituted.
@@ -292,26 +292,34 @@ public final class ClaudeCodeLauncher extends HerdrPeerLauncher {
     */
    private List<String> argvWithFleet(FleetConfig.Profile cfg, LaunchSpec spec) {
        String roleCharter = nonBlank(spec.roleCharter());
+        // CB-634: the IDE charter is only mounted when the profile also mounts the IDE MCP, and it
+        // pins every ide_* call to the member's own worktree (spec.cwd()). Ordered between role and
+        // reply — the reply charter must stay last, it is the rule that must survive.
+        String ideCharter = cfg.hasIdeMcp() ? ideCharter(spec.cwd()) : null;
        String replyCharter = nonBlank(spec.replyCharter());
        Path agentFile = agentDefinitionFile(spec.cwd(), spec.role(), ".claude", "agents");
-        if (!cfg.hasMcp() && roleCharter == null && replyCharter == null && agentFile == null) {
+        if (!cfg.mountsAnyMcp() && roleCharter == null && ideCharter == null
+                && replyCharter == null && agentFile == null) {
            return cfg.argv();
        }
        List<String> argv = mutableArgv(cfg.argv());
-        if (cfg.hasMcp()) {
-            String mcpJson = "{\"mcpServers\":{\"" + PeerLauncher.MCP_MOUNT_NAME
-                    + "\":{\"type\":\"http\",\"url\":\""
-                    + cfg.mcpUrl() + "\"}}}";
+        if (cfg.mountsAnyMcp()) {
            argv.add("--mcp-config");
-            argv.add(mcpJson);
+            argv.add(mcpConfigJson(cfg));
        }
-        if (roleCharter != null) {
-            String combined = replyCharter == null ? roleCharter : roleCharter + "\n\n" + replyCharter;
-            argv.add("--append-system-prompt-file");
-            argv.add(writeCharterFile(combined).toString());
-        } else if (replyCharter != null) {
+        // Combine the charters in order role -> ide -> reply, dropping any that are absent. When two
+        // or more survive they must ride one --append-system-prompt-file (CB-618 forbids the inline
+        // flag and the file flag together). A lone reply charter keeps its proven inline delivery.
+        List<String> charters = new java.util.ArrayList<>(3);
+        if (roleCharter != null) charters.add(roleCharter);
+        if (ideCharter != null) charters.add(ideCharter);
+        if (replyCharter != null) charters.add(replyCharter);
+        if (charters.size() == 1 && replyCharter != null && roleCharter == null && ideCharter == null) {
            argv.add("--append-system-prompt");
            argv.add(replyCharter);
+        } else if (!charters.isEmpty()) {
+            argv.add("--append-system-prompt-file");
+            argv.add(writeCharterFile(String.join("\n\n", charters)).toString());
        }
        if (agentFile != null) {
            argv.add("--agent");
@@ -320,6 +328,44 @@ public final class ClaudeCodeLauncher extends HerdrPeerLauncher {
        return argv;
    }

+    /**
+     * The {@code --mcp-config} JSON for this member: always the bridge mount when {@link
+     * FleetConfig.Profile#hasMcp()}, plus the IDE Index MCP as a second server named {@code
+     * intellij} when {@link FleetConfig.Profile#hasIdeMcp()} (CB-634). At least one is present —
+     * the caller only reaches here when {@link FleetConfig.Profile#mountsAnyMcp()} is true.
+     */
+    private static String mcpConfigJson(FleetConfig.Profile cfg) {
+        StringBuilder servers = new StringBuilder();
+        if (cfg.hasMcp()) {
+            servers.append('"').append(PeerLauncher.MCP_MOUNT_NAME)
+                    .append("\":{\"type\":\"http\",\"url\":\"").append(cfg.mcpUrl()).append("\"}");
+        }
+        if (cfg.hasIdeMcp()) {
+            if (servers.length() > 0) servers.append(',');
+            servers.append("\"intellij\":{\"type\":\"http\",\"url\":\"")
+                    .append(cfg.ideMcpUrl()).append("\"}");
+        }
+        return "{\"mcpServers\":{" + servers + "}}";
+    }
+
+    /**
+     * The IDE charter fragment (CB-634): tells the member to prefer the mounted IDE Index MCP over
+     * text search, and — the load-bearing rule — to pin every {@code ide_*} call to its own
+     * worktree. A bare call errors {@code multiple_projects_open}; a call with any other path reads
+     * a different checkout, which is exactly the CB-525 wrong-tree failure this pin prevents.
+     */
+    private static String ideCharter(String worktree) {
+        return "## IDE code intelligence — your worktree only\n"
+                + "An IntelliJ IDE Index MCP server is mounted as `mcp__intellij__ide_*`. Prefer it "
+                + "over `grep`/`find` for symbol lookups, references, call and type hierarchy, and "
+                + "diagnostics — it resolves the real AST, text search does not.\n\n"
+                + "Every `ide_*` call MUST pass `project_path: \"" + worktree + "\"` — your own "
+                + "worktree — and never any other path. A call without it errors "
+                + "`multiple_projects_open`; a call with a different path reads another checkout, "
+                + "not your changes. This is not the primary's IDE: it is your worktree, pinned to "
+                + "you.";
+    }
+
    /** {@code s}, or {@code null} when {@code s} is null/blank — the charter-presence test used above. */
    private static String nonBlank(String s) {
        return (s == null || s.isBlank()) ? null : s;