Email Agent Repo Guide

This skill gives you deep knowledge of the Email Agent codebase so you can answer "how do I…" questions, explain the architecture, and guide extensions — without re-reading every file each time.

What This Repo Is

An AI-powered outbound email generator. A user creates a campaign (with a custom AI prompt + research toggles), uploads contacts via CSV or API, and each contact is processed through a durable Vercel Workflow that:

1. Researches the company (and optionally the person) via Exa
2. Generates a personalized email sequence via the Vercel AI SDK (Anthropic models)
3. Optionally syncs the prospect to Outreach CRM and enrolls them in a sequence

Stack: Next.js 15 (App Router) · React Query · Vercel AI SDK · Drizzle ORM + Neon Postgres · Exa · Outreach · Tailwind 4 + shadcn/ui · Vercel Workflows.

Architecture Map

The Core Workflow

workflows/process-contact.ts is the heart of the app. Each contact runs through it independently and concurrently (Promise.all over start(processContactWorkflow, [id])).

pending → researching → generating → sending → completed (or failed)

Steps (each is a "use step" function for durability + retries):

1. Load contact + campaign from DB (stepLoadContactAndCampaign) — FatalError if missing
2. Research company via Exa → summarized by AI (stepResearchCompany) — only if campaign.researchEnabled
3. Research person via Exa → verified by AI (stepResearchPerson) — only if campaign.peopleResearchEnabled
4. Save research to contacts.companyResearch / peopleResearch (JSONB)
5. Generate email via generateText with structured Output.object (stepGenerateEmail)
6. Save email to contacts.generatedSubject + generatedBody1/2/3
7. Outreach (if campaign.outreachMode !== 'none'): upsert prospect → set custom fields → optionally add to sequence
8. Mark completed (or failed with error message in contacts.data.error)

Workflow launch points:

• services/contacts.ts:processAllContacts — "Process N pending" button
• services/contacts.ts:addAndProcessContacts — after CSV upload
• app/api/contacts/route.ts — after API contact creation

External Integrations & APIs

Exa (research) — lib/exa.ts, lib/research/

• Env var: EXA_API_KEY
• Client: exa-js SDK, singleton via getExaClient()
• Calls: exa.searchAndContents(query, { numResults, type: 'auto', category, summary: true })
• Company research (lib/research/company.ts): two parallel searches (category: 'company' + category: 'news'), results summarized by anthropic/claude-haiku-4-5 into { companySummary, existingAIFeatures[] }
• People research (lib/research/people.ts): two parallel searches (profile + activity), AI verifies isConfidentMatch (company+name must match) → returns { title, contactSummary, recentActivity[] } or null
• Error handling: both research functions catch errors and return safe fallbacks (empty research / null) rather than failing the workflow

Vercel AI SDK (email generation + summarization) — lib/email/

• Env var: AI_GATEWAY_API_KEY (Vercel AI Gateway)
• Email generation (workflows/process-contact.ts:stepGenerateEmail): generateText({ model: 'anthropic/claude-opus-4.6', output: Output.object({ schema }), prompt })
• Research summarization: anthropic/claude-haiku-4-5 with Output.object + Zod schema
• Prompt builder: lib/email/generation.ts:buildEmailGenerationPrompt assembles sections: contact info, instructions (campaign system prompt), company research, people research, format requirements
• Output schema: lib/email/schema.ts:createEmailGenerationSchema(n) — dynamically builds Zod object with subject + body1..bodyN (max 2 follow-ups = 3 bodies)
• Default prompt: DEFAULT_SYSTEM_PROMPT in lib/email/generation.ts — 3-email F-shaped sequence, ~75 words each, HTML <p> formatting

Outreach (CRM) — lib/outreach/

• Env vars: OUTREACH_CLIENT_ID, OUTREACH_CLIENT_SECRET, OUTREACH_REDIRECT_URI
• OAuth flow: services/outreach.ts:getOutreachAuthUrl → user authorizes at api.outreach.io/oauth/authorize → callback at /api/oauth/outreach/callback → token exchange → stored in oauth_tokens table
• Token refresh: lib/outreach/client.ts:refreshAccessToken auto-refreshes if within 5 min of expiry
• API base: https://api.outreach.io, JSON:API format (Content-Type: application/vnd.api+json)
• Custom fields: subject → custom92, bodies → custom93/94/95 (hardcoded in lib/outreach/prospects.ts and sequences.ts)
• Endpoints used:
  • GET /api/v2/prospects?filter[emails]=… — find by email
  • POST /api/v2/prospects — create prospect
  • PATCH /api/v2/prospects/:id — set custom fields
  • POST /api/v2/sequenceStates — add prospect to sequence
  • POST /api/v2/sequences, /sequenceSteps, /templates, /sequenceTemplates — scaffoldOutreachSequence builds a full sequence

Neon Postgres — db/

• Env var: DATABASE_URL
• ORM: Drizzle (drizzle-orm/neon-http), schema in db/schema.ts
• Migrations: pnpm db:push (push) or pnpm db:generate (generate SQL)
• Tables: campaigns, contacts (FK → campaigns, cascade delete), oauth_tokens, settings

How To Extend — Common Questions

"How do I hook this up to a different CRM (instead of Outreach)?"

Mirror the Outreach pattern:

1. Create lib/<crm>/client.ts — auth + authenticated fetch wrapper (see lib/outreach/client.ts)
2. Create lib/<crm>/prospects.ts — upsertProspect, setProspectCustomFields, addProspectToSequence
3. Add an OAuth callback route at app/api/<crm>/callback/route.ts (see the Outreach callback)
4. Add a server action in services/ for generating the auth URL + checking connection
5. Add a <crm>Mode enum to db/schema.ts alongside the existing outreachMode enum, then branch in workflows/process-contact.ts (the workflow already checks campaign.outreachMode)
6. Add a settings UI component for the OAuth connect button

The workflow is the integration point — stepUpsertProspect, stepSetProspectFields, stepAddToSequence are isolated steps you can swap.

"How do I use a different research provider (instead of Exa)?"

1. Replace lib/exa.ts with a new client, or create lib/<provider>.ts
2. Rewrite lib/research/company.ts and lib/research/people.ts to call your provider's search API
3. Keep the return types CompanyResearch and PeopleResearch (defined in db/schema.ts) so the workflow and prompt builder don't need changes
4. Update the env var from EXA_API_KEY to your provider's key

The research functions are self-contained — the workflow just calls researchCompany() / researchPerson() and saves the result.

"How do I use a different AI model?"

The model is a string passed to generateText({ model: '…' }). The app uses the Vercel AI Gateway, so any model the gateway supports works:

• Email generation: anthropic/claude-opus-4.6 in workflows/process-contact.ts:222
• Research summarization: anthropic/claude-haiku-4-5 in lib/research/company.ts:53 and lib/research/people.ts:70

Just change the model string. The Output.object({ schema }) structured output pattern works across providers.

"How do I add contacts from another source (webhook, CRM sync, etc.)?"

Two options:

• API route: POST /api/contacts already exists (app/api/contacts/route.ts). It takes { campaignId, contact: { email, firstName, lastName?, companyName, context? } } and auto-starts the workflow. Point any external system at this endpoint.
• Server action: Call services/contacts.ts:addAndProcessContacts(campaignId, contactsData) directly from a server component or another server action.

"How do I add more follow-up emails?"

Currently capped at 2 follow-ups (3 total) by MAX_FOLLOW_UPS in lib/email/schema.ts. To increase:

1. Bump MAX_FOLLOW_UPS
2. Add generatedBody4, etc. columns to contacts in db/schema.ts → run pnpm db:push
3. Add more Outreach custom field slots in lib/outreach/prospects.ts (CUSTOM_FIELD_BODIES) and sequences.ts
4. Update stepSaveEmail in the workflow to save the extra bodies
5. Update the campaign form select options in components/campaign-form.tsx

"How do I add a new campaign setting?"

1. Add the column to campaigns in db/schema.ts → pnpm db:push
2. Add the form field in components/campaign-form.tsx
3. Read it in workflows/process-contact.ts (the campaign object is loaded in stepLoadContactAndCampaign)
4. If it affects the prompt, pass it through buildEmailGenerationPrompt in lib/email/generation.ts

Coding Conventions (quick reference — full detail in README.md)

• Server actions (services/, 'use server') for internal data ops. API routes (app/api/) only for external entry points (OAuth, webhooks, third-party callers).
• Vercel Workflows for anything calling external APIs or doing AI generation. Use "use workflow" + "use step". FatalError = non-retryable; regular throw = retryable.
• React Query for all client data. Query keys centralized in lib/query-keys.ts. Poll at 3s when contacts are processing. Pass SSR data as initialData.
• Drizzle types via InferSelectModel / $inferInsert — don't duplicate. JSONB for complex nested data. onDelete: 'cascade' for children. withTimezone: true timestamps.
• Components: server components by default, 'use client' only when needed. shadcn/ui for primitives. Native FormData for forms (no form libraries).
• TypeScript: strict mode, prefer inference, validate untrusted data with Zod, no any.
• Tests: integration tests in tests/ with Vitest, fileParallelism: false, real Exa + AI calls (only Outreach mocked). Use createTracker() for cleanup.

Commands

pnpm dev          # local dev server
pnpm build        # production build
pnpm lint         # next lint
pnpm test         # vitest run (needs .env.local with real API keys + DATABASE_URL)
pnpm test:watch   # vitest watch mode
pnpm db:push      # push schema changes to Neon
pnpm db:generate  # generate migration SQL
pnpm db:studio    # Drizzle Studio GUI
pnpm workflows    # inspect workflow runs (npx workflow inspect runs --web)

Environment Variables

Answering Questions

When a user asks "how do I…" about this repo:

1. Identify which integration/layer they're asking about (research, AI, CRM, DB, UI, workflow).
2. Reference the exact files above so they can navigate directly.
3. If they want to swap an integration, point them to the "How To Extend" section that matches and name the specific files to change.
4. If unsure about current behavior, read the specific file before answering — this guide is a map, not a substitute for the code.