feat(core): Model family-specific system prompts (#17614)

2026-05-12 21:03:05 -07:00 · 2026-01-27 10:21:05 -08:00
parent 894bd66dc6
commit dacc178d4e
6 changed files with 876 additions and 677 deletions
@@ -0,0 +1,203 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import fs from 'node:fs';
+import path from 'node:path';
+import process from 'node:process';
+import type { Config } from '../config/config.js';
+import { GEMINI_DIR } from '../utils/paths.js';
+import { ApprovalMode } from '../policy/types.js';
+import * as snippets from './snippets.js';
+import {
+  resolvePathFromEnv,
+  applySubstitutions,
+  isSectionEnabled,
+  type ResolvedPath,
+} from './utils.js';
+import { CodebaseInvestigatorAgent } from '../agents/codebase-investigator.js';
+import { isGitRepository } from '../utils/gitUtils.js';
+import {
+  PLAN_MODE_TOOLS,
+  WRITE_TODOS_TOOL_NAME,
+  READ_FILE_TOOL_NAME,
+} from '../tools/tool-names.js';
+import { resolveModel, isPreviewModel } from '../config/models.js';
+
+/**
+ * Orchestrates prompt generation by gathering context and building options.
+ */
+export class PromptProvider {
+  /**
+   * Generates the core system prompt.
+   */
+  getCoreSystemPrompt(
+    config: Config,
+    userMemory?: string,
+    interactiveOverride?: boolean,
+  ): string {
+    const systemMdResolution = resolvePathFromEnv(
+      process.env['GEMINI_SYSTEM_MD'],
+    );
+
+    const interactiveMode = interactiveOverride ?? config.isInteractive();
+    const approvalMode = config.getApprovalMode?.() ?? ApprovalMode.DEFAULT;
+    const isPlanMode = approvalMode === ApprovalMode.PLAN;
+    const skills = config.getSkillManager().getSkills();
+    const toolNames = config.getToolRegistry().getAllToolNames();
+
+    const desiredModel = resolveModel(
+      config.getActiveModel(),
+      config.getPreviewFeatures(),
+    );
+    const isGemini3 = isPreviewModel(desiredModel);
+
+    // --- Context Gathering ---
+    const planOptions: snippets.ApprovalModePlanOptions | undefined = isPlanMode
+      ? {
+          planModeToolsList: PLAN_MODE_TOOLS.filter((t) =>
+            new Set(toolNames).has(t),
+          )
+            .map((t) => `- \`${t}\``)
+            .join('\n'),
+          plansDir: config.storage.getProjectTempPlansDir(),
+        }
+      : undefined;
+
+    let basePrompt: string;
+
+    // --- Template File Override ---
+    if (systemMdResolution.value && !systemMdResolution.isDisabled) {
+      let systemMdPath = path.resolve(path.join(GEMINI_DIR, 'system.md'));
+      if (!systemMdResolution.isSwitch) {
+        systemMdPath = systemMdResolution.value;
+      }
+      if (!fs.existsSync(systemMdPath)) {
+        throw new Error(`missing system prompt file '${systemMdPath}'`);
+      }
+      basePrompt = fs.readFileSync(systemMdPath, 'utf8');
+      const skillsPrompt = snippets.renderAgentSkills(
+        skills.map((s) => ({
+          name: s.name,
+          description: s.description,
+          location: s.location,
+        })),
+      );
+      basePrompt = applySubstitutions(basePrompt, config, skillsPrompt);
+    } else {
+      // --- Standard Composition ---
+      const options: snippets.SystemPromptOptions = {
+        preamble: this.withSection('preamble', () => ({
+          interactive: interactiveMode,
+        })),
+        coreMandates: this.withSection('coreMandates', () => ({
+          interactive: interactiveMode,
+          isGemini3,
+          hasSkills: skills.length > 0,
+        })),
+        agentContexts: this.withSection('agentContexts', () =>
+          config.getAgentRegistry().getDirectoryContext(),
+        ),
+        agentSkills: this.withSection(
+          'agentSkills',
+          () =>
+            skills.map((s) => ({
+              name: s.name,
+              description: s.description,
+              location: s.location,
+            })),
+          skills.length > 0,
+        ),
+        hookContext: isSectionEnabled('hookContext') || undefined,
+        primaryWorkflows: this.withSection(
+          'primaryWorkflows',
+          () => ({
+            interactive: interactiveMode,
+            enableCodebaseInvestigator: toolNames.includes(
+              CodebaseInvestigatorAgent.name,
+            ),
+            enableWriteTodosTool: toolNames.includes(WRITE_TODOS_TOOL_NAME),
+          }),
+          !isPlanMode,
+        ),
+        operationalGuidelines: this.withSection(
+          'operationalGuidelines',
+          () => ({
+            interactive: interactiveMode,
+            isGemini3,
+            enableShellEfficiency: config.getEnableShellOutputEfficiency(),
+          }),
+        ),
+        sandbox: this.withSection('sandbox', () => getSandboxMode()),
+        gitRepo: this.withSection(
+          'git',
+          () => ({ interactive: interactiveMode }),
+          isGitRepository(process.cwd()) ? true : false,
+        ),
+        finalReminder: this.withSection('finalReminder', () => ({
+          readFileToolName: READ_FILE_TOOL_NAME,
+        })),
+      };
+
+      basePrompt = snippets.getCoreSystemPrompt(options);
+    }
+
+    // --- Finalization (Shell) ---
+    const finalPrompt = snippets.renderFinalShell(
+      basePrompt,
+      userMemory,
+      planOptions,
+    );
+
+    // Sanitize erratic newlines from composition
+    const sanitizedPrompt = finalPrompt.replace(/\n{3,}/g, '\n\n');
+
+    // Write back to file if requested
+    this.maybeWriteSystemMd(
+      sanitizedPrompt,
+      systemMdResolution,
+      path.resolve(path.join(GEMINI_DIR, 'system.md')),
+    );
+
+    return sanitizedPrompt;
+  }
+
+  getCompressionPrompt(): string {
+    return snippets.getCompressionPrompt();
+  }
+
+  private withSection<T>(
+    key: string,
+    factory: () => T,
+    guard: boolean = true,
+  ): T | undefined {
+    return guard && isSectionEnabled(key) ? factory() : undefined;
+  }
+
+  private maybeWriteSystemMd(
+    basePrompt: string,
+    resolution: ResolvedPath,
+    defaultPath: string,
+  ): void {
+    const writeSystemMdResolution = resolvePathFromEnv(
+      process.env['GEMINI_WRITE_SYSTEM_MD'],
+    );
+    if (writeSystemMdResolution.value && !writeSystemMdResolution.isDisabled) {
+      const writePath = writeSystemMdResolution.isSwitch
+        ? defaultPath
+        : writeSystemMdResolution.value;
+      fs.mkdirSync(path.dirname(writePath), { recursive: true });
+      fs.writeFileSync(writePath, basePrompt);
+    }
+  }
+}
+
+// --- Internal Context Helpers ---
+
+function getSandboxMode(): snippets.SandboxMode {
+  if (process.env['SANDBOX'] === 'sandbox-exec') return 'macos-seatbelt';
+  if (process.env['SANDBOX']) return 'generic';
+  return 'outside';
+}