FastMCP Server For Apollo

Apollo.io MCP Server

FastMCP server exposing the full operational surface of the Apollo.io REST API to Claude Code. 27 tools covering sequences, campaign health, mailbox warmup, people/org enrichment, CRM contacts, tasks, labels, credit tracking, AND programmatic template/sequence/mailbox-cap editing with audit logging.

Most existing Apollo MCPs only expose people search and enrichment. This one is built for teams running outbound at scale — daily health digests, sequence management, mailbox deliverability monitoring, programmatic contact enrollment, and end-to-end sequence authoring without touching the Apollo UI.

Quick reference

apollo_campaign_health                — daily digest (start here)
apollo_messages_search days_back=1    — raw send/open/reply/bounce log
apollo_mailbox_warmup                 — per-mailbox deliverability state
apollo_sequences_list                 — all sequences + labels + stats
apollo_sequence_add_contacts ...      — enroll contacts into a sequence
apollo_template_update ...            — update template body + subject (with audit log)
apollo_sequence_create ...            — author a new sequence end-to-end
apollo_step_create ...                — add a step + template to a sequence
apollo_mailbox_update_cap ...         — change daily send cap
apollo_credits_remaining              — monthly credit budget check
apollo_health                         — self-check (also probes master key)

Tool inventory (27)

Campaign health

• apollo_campaign_health(days_back=1) — digest across all sequences + mailboxes
• apollo_mailbox_warmup() — per-mailbox warmup status and daily limits
• apollo_sequence_get(sequence_id) — one-sequence deep-dive

Sequences

• apollo_sequences_list() — list all sequences with stats
• apollo_sequence_add_contacts(sequence_id, contact_ids, send_email_from_email_account_id?)
• apollo_sequence_remove_contacts(sequence_id, contact_ids)
• apollo_sequence_set_active(sequence_id, active) — activate or pause

Messages / analytics

• apollo_messages_search(days_back, sequence_ids?, stats?, per_page, max_pages)

People / orgs

• apollo_people_search(...) — free (no credit burn)
• apollo_person_enrich(...) — 1 credit per revealed email
• apollo_bulk_person_enrich(people, reveal_personal_emails?) — up to 10/call
• apollo_org_search(...)
• apollo_org_enrich(domain)
• apollo_org_job_postings(organization_id)

CRM

• apollo_contacts_search(...)
• apollo_contact_create(...)
• apollo_contact_update(contact_id, fields)
• apollo_contact_stages()

Tasks / labels / credits

• apollo_task_create(...)
• apollo_labels_list()
• apollo_label_create(name)
• apollo_credits_remaining()

Template + sequence authoring (destructive writes)

• apollo_template_get(template_id) — fetch current template state
• apollo_template_update(template_id, subject?, body_text?, body_html?, audit_label?) — update template subject + body. Snapshots current state to APOLLO_AUDIT_LOG_PATH (if set) BEFORE the write so any breakage is reversible from the diff
• apollo_sequence_create(name, label?, permissions?, active?) — create a new sequence (paused by default)
• apollo_step_create(sequence_id, position, wait_days, subject, body_text, body_html?, step_type?, include_signature?) — create a step + touch + template in one call
• apollo_mailbox_update_cap(mailbox_id, daily_send_limit, audit_label?) — change daily send cap on a mailbox. Audits before/after.

Diagnostics

• apollo_health() — probes API key validity + master-key hint

Configuration

Copy config.example.yaml to config.yaml and fill in your values:

cp config.example.yaml config.yaml

config.yaml is gitignored. Key fields:

Env vars:

Install

Open Claude Code, paste:

/plugin marketplace add adelaidasofia/apollo-mcp
/plugin install apollo-mcp@apollo-mcp

Then set APOLLO_API_KEY (must be a master key) in your environment and restart Claude Code.

pip3 install -r requirements.txt
python3 -c "import server; print('OK')"

Add to your .mcp.json:

{
  "mcpServers": {
    "apollo": {
      "command": "python3",
      "args": ["/path/to/apollo-mcp/server.py"],
      "env": {
        "APOLLO_API_KEY": "your-master-key-here"
      }
    }
  }
}

Restart Claude Code after editing .mcp.json.

Known gotchas

1. MASTER key required for /emailer_campaigns, /emailer_messages/search, /email_accounts, /usage_stats/*. Standard keys return 403. apollo_health probes for this automatically.

2. Rate limit ~60 req/min. Built-in jittered exponential backoff handles 429s transparently.

3. Pagination hard-capped at 50 pages × 100/page = 5,000 records per call. Slice by date for deeper queries.

4. Credit burn — apollo_person_enrich(reveal_personal_emails=True) and the bulk variant each burn 1 credit.

5. 5-minute in-memory cache for sequences_list, email_accounts, labels, contact_stages. Force-refresh by restarting Claude Code.

6. Cloudflare 1010 on default Python UAs. apollo.io returns HTTP 403 with body error code: 1010 when it sees python-urllib/* or python-httpx/* user-agents. The server spoofs apollo-mcp/1.0 (curl/8.0.0) to bypass. If you build any adjacent scripts hitting apollo.io, add the same User-Agent header or you'll debug a phantom 403 that looks like a missing master key.

7. No working sequence-scoped unenroll endpoint. POST /emailer_campaigns/{id}/remove_contact_ids returns 404. The no-ID variant POST /emailer_campaigns/remove_contact_ids returns 200 but is a silent no-op regardless of payload. The only reliable unenroll path is DELETE /contacts/{id}, which cascades all campaign enrollments. Destructive: the contact record is marked deleted: true. apollo_sequence_remove_contacts wraps this.

8. GET /emailer_campaigns creates an empty sequence. Use POST /emailer_campaigns/search to list sequences. The server does this correctly — just be careful if you hit the API directly.

9. Sequence activation uses PUT, not a sub-resource. The correct endpoint to activate or pause a sequence is PUT /emailer_campaigns/{id} with body {"emailer_campaign": {"active": true/false}}. Sub-resource paths like /check_contacts return 404.

Scripts

• scripts/daily_digest.py — standalone script that pulls yesterday's stats and prepends them to a markdown dashboard. Run via cron or manually.
• scripts/bootstrap_sequences.py — create sequences programmatically from code. Useful for version-controlling email copy. Includes the undocumented POST /emailer_touches/{id}/approve endpoint needed to move steps out of draft state.

Related MCPs

Same author, same architecture pattern (FastMCP, draft+confirm on writes where applicable, vault auto-export, MIT):

• slack-mcp — multi-workspace Slack
• imessage-mcp — macOS iMessage
• whatsapp-mcp — WhatsApp via whatsmeow
• google-workspace-mcp — Gmail / Calendar / Drive / Docs / Sheets
• substack-mcp — Substack writing + analytics
• luma-mcp — lu.ma events
• parse-mcp — markitdown / Docling / LlamaParse router
• rescuetime-mcp — RescueTime productivity data
• graph-query-mcp — vault knowledge graph queries
• graph-autotagger-mcp — wikilink suggestions from the graph
• investor-relations-mcp — seed-raise pipeline tracker
• vault-sync-mcp — bidirectional vault sync

Telemetry

This plugin sends a single anonymous install signal to myceliumai.co the first time it loads in a Claude Code session on a given machine.

What is sent:

• Plugin name (e.g. slack-mcp)
• Plugin version (e.g. 0.1.0)

What is NOT sent:

• No user identifiers, names, emails, tokens, or API keys
• No file paths, message content, or anything from your work
• No IP address is stored after dedup processing

Why: Helps the maintainer know which plugins people actually install, so attention goes to the ones that get used.

Opt out: Set the environment variable MYCELIUM_NO_PING=1 before launching Claude Code. The hook will skip the network call entirely. Already-pinged installs leave a sentinel at ~/.mycelium/onboarded-<plugin> — delete it if you want to reset state.

License

MIT

Built by Mycelium AI. Full install or team version at diazroa.com.