Vapi Bootstrap Framework

Vapi bootstrap framework

Experimental reference workflow: This skill recreates the architecture used for Vapi's landing-page agents. It is not the standard workflow for building Vapi assistants and should only be used when explicitly requested.

Scaffold an entire Vapi voice-agent project from a single ROUGH_DRAFT.md spec. Works in an empty folder or alongside an existing Bun + TypeScript project. One bun run bootstrap after this skill finishes puts the whole fleet live in dashboard.vapi.ai.

What this skill produces

Project scaffolding (only created if absent — never overwritten):

• package.json — Bun + @vapi-ai/server-sdk + a bootstrap script
• tsconfig.json — strict no-emit TypeScript validation
• .env.example — VAPI_API_KEY placeholder + one slot per (scenario × language) tuple
• .gitignore — node_modules, .env*.local, OS junk

Framework spine (always created — architectural; every later change extends a slot here, never the spine itself):

• src/assistants/languages.ts — per-language voice + transcriber stack
• src/assistants/loadPrompt.ts — loadPrompt(scenarioId, languageId) composer
• src/assistants/scenarios/index.ts — the scenario registry
• src/assistants/buildAssistant.ts — composes a full Vapi assistant body for any (scenarioId, languageId) tuple
• src/assistants/prompts/shared/preambles/es.md — Spanish language preamble (extend with more languages later)

Content (always created — one set per scenario detected in the rough draft):

• src/assistants/scenarios/<scenarioId>.ts — id, name, language-keyed first message
• src/assistants/prompts/<scenarioId>/body.md — rough first-draft system prompt
• src/assistants/prompts/<scenarioId>/off-topic-es.md — Spanish redirect lines

Entry point (always created):

• src/bootstrap.ts — idempotent double loop over scenarios × languages

Defaults: languages en + es. Model openai gpt-4.1 temperature 0.5. Voices ElevenLabs eleven_turbo_v2 (EN) / eleven_multilingual_v2 (ES). Transcriber Deepgram nova-3 (EN) / Soniox stt-rt-v4 (ES). Override these only if the user explicitly asks.

Workflow

1. Check for ROUGH_DRAFT.md at the project root.
   • If present → continue with step 2.
   • If missing → tell the user the skill needs a rough draft to work from. Offer the template under "ROUGH_DRAFT.md template" below; either paste it in for them to fill out, or wait for them to provide their own. Don't proceed past this step without one.
2. Detect scenarios — every ## N. <scenario name> heading is one scenario. Derive a snake_case scenarioId from the name (e.g. "Lead Qualification & Screening" → qualification; "Appointment Scheduling" → appointment). When in doubt, pick the shortest unambiguous noun. Keep ids short — they become env var names.
3. Extract the opening line — under each scenario, look for **On the page**, **Opening**, **Greeting**, or the first quoted string in the section. That's firstMessage.en verbatim.
4. Distill the flow — **What happens** (or equivalent prose) becomes a rough first-draft body.md. Persona-driven, not a contract — no failure rules, no exact wordings, no scripted off-ramps yet. Keep it short.
5. Scaffold the project root — for each of package.json, tsconfig.json, .env.example, .gitignore: if the file is absent, create it from the template below. If .env.example already exists, append any missing VAPI_ASSISTANT_<SCENARIO>_<LANG> slots; never reorder or remove existing lines. If package.json exists, leave it alone but verify it has @vapi-ai/server-sdk in deps plus bootstrap and typecheck scripts — tell the user if any are missing instead of editing.
6. Generate the framework spine — copy the five spine files verbatim from the templates below. They don't change between projects; only the scenario registry's imports do.
7. Generate per-scenario files — one scenarios/<id>.ts, one prompts/<id>/body.md, one prompts/<id>/off-topic-es.md per detected scenario.
8. Wire up the registry — scenarios/index.ts imports every scenario and exports the SCENARIOS const, ScenarioId, SCENARIO_IDS, scenarioFor.
9. Write src/bootstrap.ts with the double-loop template below.
10. Translate first messages to Spanish — natural Latin American Spanish, brand names untranslated.
11. Tell the user how to run it (see "Verification" below).

Keep each scenario's clientTools array empty in this skill — functional capture tools land in a follow-up step. Do not rewrite body.md as a contract here either — that's a separate step.

File templates

Templates use these placeholders that you substitute per project:

• <PROJECT_NAME> — slug from the rough draft title (# Rough draft — <X> → snake/kebab-case of X). Fallback: vapi-voice-agents.
• <SCENARIO_ID> — snake_case scenario id (e.g. qualification)
• <SCENARIO_NAME> — human-readable name (e.g. Lead Qualification)
• <FIRST_MESSAGE_EN> — verbatim opening line from the rough draft
• <FIRST_MESSAGE_ES> — natural Spanish translation
• <BODY_DRAFT> — distilled rough first-draft prompt
• <SCENARIO_IMPORTS> — one import { <id> } from "./<id>.ts"; per scenario, alphabetized
• <SCENARIO_KEYS> — comma-separated scenario ids inside SCENARIOS = { ... }
• <ENV_ASSISTANT_SLOTS> — one commented line per (scenario × language): # VAPI_ASSISTANT_<SCENARIO>_<LANG>=

package.json (only if absent)

{
  "name": "<PROJECT_NAME>",
  "version": "0.1.0",
  "private": true,
  "type": "module",
  "scripts": {
    "bootstrap": "bun run src/bootstrap.ts",
    "typecheck": "tsc --noEmit"
  },
  "dependencies": {
    "@vapi-ai/server-sdk": "^1.2.0"
  },
  "devDependencies": {
    "@types/bun": "^1.3.13",
    "typescript": "^5.9.3"
  },
  "packageManager": "bun@1.3.1"
}

tsconfig.json (only if absent)

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "allowImportingTsExtensions": true,
    "noEmit": true,
    "strict": true,
    "types": ["bun"]
  },
  "include": ["src/**/*.ts"]
}

.env.example (create if absent; extend if present)

# Get this from https://dashboard.vapi.ai/keys
VAPI_API_KEY=

# One slot per (scenario × language). First `bun run bootstrap` prints the
# ids; paste them here, then re-run for idempotent updates.
<ENV_ASSISTANT_SLOTS>

.gitignore (only if absent)

# dependencies
node_modules

# env (local-only secrets)
.env*.local

# os junk
.DS_Store

# bun
*.tsbuildinfo

src/assistants/languages.ts

/**
 * Per-language voice + transcriber stack. Adding a 3rd language is one
 * entry in each record below.
 */
import type { LanguageId } from "./loadPrompt.ts";

export type { LanguageId };

interface VoiceConfig {
  provider: "11labs";
  model: string;
  voiceId: string;
}

interface TranscriberConfig {
  provider: "deepgram" | "soniox";
  model: string;
  language: string;
}

const VOICE_BY_LANGUAGE: Record<LanguageId, VoiceConfig> = {
  en: {
    provider: "11labs",
    model: "eleven_turbo_v2",
    voiceId: "ZoiZ8fuDWInAcwPXaVeq",
  },
  es: {
    provider: "11labs",
    model: "eleven_multilingual_v2",
    voiceId: "JYyJjNPfmNJdaby8LdZs",
  },
};

const TRANSCRIBER_BY_LANGUAGE: Record<LanguageId, TranscriberConfig> = {
  en: { provider: "deepgram", model: "nova-3", language: "en" },
  es: { provider: "soniox", model: "stt-rt-v4", language: "es" },
};

export const voiceFor = (languageId: LanguageId): VoiceConfig =>
  VOICE_BY_LANGUAGE[languageId];

export const transcriberFor = (languageId: LanguageId): TranscriberConfig =>
  TRANSCRIBER_BY_LANGUAGE[languageId];

src/assistants/loadPrompt.ts

/**
 * EN returns body.md unchanged. ES prepends a Spanish preamble with the
 * scenario's off-topic redirects spliced into {{OFF_TOPIC_LINES}}.
 * One body.md per scenario drives every language variant.
 */
import { readFileSync } from "node:fs";
import { resolve } from "node:path";

export type LanguageId = "en" | "es";

const PROMPT_DIR = resolve(import.meta.dir, "prompts");

const read = (relativePath: string): string =>
  readFileSync(resolve(PROMPT_DIR, relativePath), "utf8");

export const loadPrompt = (
  scenarioId: string,
  languageId: LanguageId,
): string => {
  const body = read(`${scenarioId}/body.md`);
  if (languageId === "en") return body;

  const offTopic = read(`${scenarioId}/off-topic-${languageId}.md`).trim();
  const preamble = read(`shared/preambles/${languageId}.md`).replace(
    "{{OFF_TOPIC_LINES}}",
    offTopic,
  );
  return `${preamble}\n\n${body}`;
};

src/assistants/scenarios/index.ts

/**
 * Scenario registry. Adding a new scenario is one entry here plus one new
 * file under `./<scenario-id>.ts` and matching prompts under `../prompts/<id>/`.
 */
// <SCENARIO_IMPORTS>

export const SCENARIOS = {
  // <SCENARIO_KEYS>
} as const;

export type ScenarioId = keyof typeof SCENARIOS;

export const SCENARIO_IDS = Object.keys(SCENARIOS) as ScenarioId[];

export const scenarioFor = (id: ScenarioId) => SCENARIOS[id];

src/assistants/buildAssistant.ts

/**
 * Compose a full Vapi assistant body for a (scenario, language) tuple.
 * Voice + transcriber come from languages.ts; prompt from loadPrompt;
 * name + firstMessage + clientTools from the scenario.
 */
import { transcriberFor, voiceFor } from "./languages.ts";
import { loadPrompt, type LanguageId } from "./loadPrompt.ts";
import { scenarioFor, type ScenarioId } from "./scenarios/index.ts";

export type { LanguageId, ScenarioId };

export const buildAssistant = (
  scenarioId: ScenarioId,
  languageId: LanguageId,
) => {
  const scenario = scenarioFor(scenarioId);
  const systemPrompt = loadPrompt(scenarioId, languageId);

  return {
    name: `${languageId.toUpperCase()} - ${scenario.name}`,
    firstMessage: scenario.firstMessage[languageId],
    voice: voiceFor(languageId),
    transcriber: transcriberFor(languageId),
    model: {
      provider: "openai" as const,
      model: "gpt-4.1",
      temperature: 0.5,
      messages: [{ role: "system" as const, content: systemPrompt }],
      tools: scenario.clientTools,
    },
  };
};

src/assistants/scenarios/<SCENARIO_ID>.ts

/**
 * <SCENARIO_NAME> scenario. Plain data: id, name, language-keyed first
 * message. Later steps add `clientTools` (capture tools fire mid-call).
 */
// Rename `scenarioId` to the generated <SCENARIO_ID> identifier.
export const scenarioId = {
  id: "<SCENARIO_ID>" as const,
  name: "<SCENARIO_NAME>",
  firstMessage: {
    en: "<FIRST_MESSAGE_EN>",
    es: "<FIRST_MESSAGE_ES>",
  },
  clientTools: [] as const,
};

// Rename this type to the generated <PascalCase scenario id>Scenario name.
export type ScenarioIdScenario = typeof scenarioId;

If <FIRST_MESSAGE_EN> is long, break it across concatenated string segments for readability (one logical clause per line, joined with " + ").

src/assistants/prompts/<SCENARIO_ID>/body.md

Rough first draft — persona-driven, not a contract. Suggested shape:

# <SCENARIO_NAME> voice agent

You are the <SCENARIO_NAME> voice agent for Vapi. <One sentence on context — who you're talking to and why.>

<One paragraph distilling **What happens** from the rough draft: the questions to ask, the data to collect, the routing logic, the wrap-up.>

Be warm and curious. Ask one question at a time. If they go off-topic, redirect briefly and return to the next missing field. Keep replies short — you are speaking, not typing.

No ## Absolute rules, no failure rules, no scripted off-ramps. Those are a later step.

src/assistants/prompts/<SCENARIO_ID>/off-topic-es.md

Two short Spanish redirect lines specific to this scenario:

- "Buena pregunta — el equipo te puede ayudar con eso. ¿Podemos seguir con <next field>?"
- "Tomo nota, lo vemos después. Mientras tanto, cuéntame <one short ask tied to the scenario>."

src/assistants/prompts/shared/preambles/es.md

# IDIOMA / LANGUAGE OVERRIDE

The contract that follows this preamble is written in English. **This call is in Spanish.**

Override the language rule of the contract:

- ALL agent speech MUST be in natural, conversational Latin American Spanish. Translate the exact wordings, examples, and acks from the contract — don't switch back to English mid-sentence.
- Read brand and product names in their original form. Don't translate them.
- When you call any capture tool, **always pass free-text fields as a short English summary**, regardless of the call language. Cross-language analytics depend on it.

## Off-topic redirects (use verbatim)

If the visitor goes off-topic, pick one of these and then return to the next missing field:

{{OFF_TOPIC_LINES}}

---

src/bootstrap.ts

/**
 * Idempotent upsert across (scenario × language). One entry per tuple, keyed
 * by VAPI_ASSISTANT_<SCENARIO>_<LANG>. First run creates + prints ids;
 * subsequent runs update in place.
 *
 * Run with `bun run bootstrap`. Bun auto-loads .env.local.
 */
import { VapiClient } from "@vapi-ai/server-sdk";

import {
  buildAssistant,
  type LanguageId,
  type ScenarioId,
} from "./assistants/buildAssistant.ts";
import { SCENARIO_IDS } from "./assistants/scenarios/index.ts";

const LANGUAGES: LanguageId[] = ["en", "es"];

const envVarFor = (scenarioId: ScenarioId, languageId: LanguageId): string =>
  `VAPI_ASSISTANT_${scenarioId.toUpperCase()}_${languageId.toUpperCase()}`;

const requireEnv = (name: string): string => {
  const value = process.env[name];
  if (!value) {
    console.error(`✗ Missing env var: ${name}. See .env.example.`);
    process.exit(1);
  }
  return value;
};

const main = async () => {
  const vapi = new VapiClient({ token: requireEnv("VAPI_API_KEY") });
  const created: Array<{ envVar: string; id: string }> = [];

  for (const scenarioId of SCENARIO_IDS) {
    for (const languageId of LANGUAGES) {
      const envVar = envVarFor(scenarioId, languageId);
      const existingId = process.env[envVar];
      const body = buildAssistant(
        scenarioId,
        languageId,
      ) as unknown as Parameters<typeof vapi.assistants.create>[0];

      const label = `${scenarioId}/${languageId}`;
      let updated = false;

      if (existingId) {
        try {
          await vapi.assistants.update({
            id: existingId,
            ...body,
          } as unknown as Parameters<typeof vapi.assistants.update>[0]);
          console.log(`✓ Updated ${label} → ${existingId}`);
          updated = true;
        } catch (err) {
          const statusCode = (err as { statusCode?: number })?.statusCode;
          if (statusCode === 404) {
            console.log(
              `  ${envVar}=${existingId} not found in this org; creating a new assistant.`,
            );
          } else {
            throw err;
          }
        }
      }

      if (!updated) {
        const assistant = await vapi.assistants.create(body);
        console.log(`✓ Created ${label} → ${assistant.id}`);
        created.push({ envVar, id: assistant.id });
      }
    }
  }

  if (created.length > 0) {
    console.log("\nAdd these to .env.local:");
    for (const { envVar, id } of created) {
      console.log(`  ${envVar}=${id}`);
    }
    console.log(
      "\nThen re-run `bun run bootstrap` to confirm idempotent updates.",
    );
  } else {
    console.log(
      `\nAll ${SCENARIO_IDS.length * LANGUAGES.length} assistants updated in place.`,
    );
  }
};

main().catch((err) => {
  console.error("✗ Bootstrap failed:", err);
  process.exit(1);
});

ROUGH_DRAFT.md template

If the user has no rough draft yet, offer this skeleton (they fill in the angle-brackets and the skill scaffolds the project from it):

# Rough draft — <project name>

## 1. <First scenario name>

**On the page**: "<one verbatim opening line the agent will say>"

**What happens**: <One paragraph: the questions the agent asks, the data it collects, what it does with edge cases, how it wraps up.>

## 2. <Second scenario name>

**Opening**: "<one verbatim opening line>"

**What happens**: <One paragraph.>

One scenario is fine. Three is fine too. The skill scales the bootstrap loop to whatever's in the rough draft.

Adapting the defaults

If the user asks for different defaults, change only the matching slot — never the surrounding shape:

• Different languages: add an entry to VOICE_BY_LANGUAGE and TRANSCRIBER_BY_LANGUAGE, extend the LanguageId union in loadPrompt.ts, add a prompts/shared/preambles/<lang>.md, add a firstMessage.<lang> per scenario, add the lang to LANGUAGES in bootstrap.ts, and add the matching VAPI_ASSISTANT_<SCENARIO>_<LANG> slots to .env.example.
• Different model / temperature: change buildAssistant.ts only.
• Different voice provider: update VoiceConfig + VOICE_BY_LANGUAGE in languages.ts only.

Verification

After generating files, tell the user to run:

bun install
bun run typecheck              # validates locally; creates nothing in Vapi
cp .env.example .env.local     # add VAPI_API_KEY from dashboard.vapi.ai/org/api-keys
bun run bootstrap              # creates one assistant per (scenario × language)
# paste the printed VAPI_ASSISTANT_<SCENARIO>_<LANG>=<id> lines into .env.local
bun run bootstrap              # second run prints "Updated ..." for every tuple

For N scenarios × 2 languages they should see N × 2 assistants in dashboard.vapi.ai. Each one has a green "Talk to assistant" button — the agents will walk the flow but are still rough (no failure rules, no capture tools yet). That's expected; later prompts harden them.