Warmerly
API and 16 mailbox-health webhooks on Agency; an MCP server on every plan. No CRM sync found. LinkedIn is $19 a month per account.
Warmerly
Apollo.io
One-to-one · Integrations, API and LinkedIn
Integrations, API and LinkedIn
One row, in depth: what each tool does, the verified numbers, and who each suits.
Apollo details read from its pricing page and FAQ, product pages and help centre on 21 October 2026.
Warmerly
API and 16 mailbox-health webhooks on Agency; an MCP server on every plan. No CRM sync found. LinkedIn is $19 a month per account.
Apollo.io
CRM integrations from Basic, with Salesforce and HubSpot named; a Chrome extension and an MCP. API access on Custom plans per its FAQ.
The short answer
Integrations, API and LinkedIn, in one look.
Warmerly has an API and 16 mailbox-health webhooks on Agency, an MCP server on every plan, and a LinkedIn add-on at $19 a month per account, but we found no CRM sync. Apollo is ahead on connections to other tools: CRM integrations from Basic, with Salesforce, HubSpot, Outreach, SalesLoft, Marketo, Sendgrid and LinkedIn named in its FAQ, a Chrome extension and an MCP. Apollo's own pages disagree on which plans get its API, so check that before you build on it. Last checked 22 October 2026.
Apollo.ioApollo.io ahead on this row
CRM integrations from Basic, with Salesforce and HubSpot named; a Chrome extension and an MCP. API access on Custom plans per its FAQ.
The picture
Drawn side by side.
What each connects to
As each describes it
WarmerlyApollo.io
Warmerly
Agency plan API16 mailbox-health webhooksMCP server on every planLinkedIn add-on, $19 a month
Apollo.io
CRM integrations from BasicSalesforce, HubSpot and others namedChrome extension and MCPAPI on Custom plans
We found no CRM sync in Warmerly. Apollo's home page claims 200+ integrations and its directory page shows 69 results, so we do not state a count.
How Warmerly does it
Warmerly, in detail.
A developer surface for mailbox health and campaigns, an MCP server for AI tools, and LinkedIn as an add-on.
01
An API, on the Agency plan
API keys need the Agency plan ($179 a month), and a free trial of Agency includes them. Keys go in an X-Api-Key header, each user can hold up to 10, and the default limit is 60 requests a minute per key, which can be raised to a cap of 120 when you create the key.
Warmerly product, checked 21 October 2026
02
16 mailbox-health webhooks
Outbound webhooks are signed POSTs about mailbox health, with 16 event types such as score_drop, auth_fail and dns_changed. They do not cover opens, clicks or replies. Agency only, and deliveries pause while the owner is not on Agency.
Warmerly product, checked 21 October 2026
03
How webhook delivery behaves
A sweep runs every 5 minutes, so events are not real-time. Each delivery is tried up to 3 times and fails if your endpoint does not answer 2xx within 5 seconds. An event that fails all 3 attempts is not redelivered. Each user can hold up to 10 subscriptions, and the target must be a public https URL.
Warmerly product, checked 21 October 2026
04
An MCP server on every plan
An MCP server lets Claude, ChatGPT, Claude Code and Cursor read and act in a workspace after an OAuth sign-in. It is on every plan including Free, and no tool can start or resume campaign sending. You choose one workspace or all of yours when you sign in.
Warmerly product, checked 21 October 2026
05
A Claude plugin with four workflows
Warmerly publishes an open-source plugin with four skills: launch an outreach campaign, diagnose deliverability, triage replies and set up transactional email. Each asks before bulk sends, launches or replies unless you tell it not to.
Warmerly product, checked 21 October 2026
06
LinkedIn as an add-on
A LinkedIn account is $19 a month with no trial, and runs connection and message steps inside the same sequence as email. A 3-account pack is $49 a month and a 5-account pack $75.
Warmerly product, checked 21 October 2026
07
Zapier is a name in the docs, not a connector
The API help page says scripts or tools like Zapier can use a key, and the keys page uses Zapier as an example key name. We found no Zapier app or native connector, so it is the API you would be calling.
Warmerly product, checked 21 October 2026
08
No CRM sync found
We searched the product code and docs for HubSpot, Pipedrive and Salesforce connectors and found none as integrations. If one exists outside the repo, we did not find it.
Warmerly product, checked 21 October 2026
How Apollo.io does it
Apollo.io, in detail.
A wide connector list and a Chrome extension, with CRM links on paid plans and an API whose plan rules are described three different ways.
01
CRM integrations from Basic
The price cards list CRM Integrations on Basic, Professional and Organization, and Automated CRM Enrichment from Basic. The comparison table has rows for CRM Integrations (Salesforce, HubSpot, Pipedrive), Salesforce Custom Objects and Outreach and SalesLoft Integration. The text we read does not show which plan each row applies to.
apollo.io/pricing · read 22 October 2026
02
Named tools
The FAQ says Apollo integrates with Salesforce, HubSpot, Outreach, SalesLoft, Marketo, Sendgrid, LinkedIn and all major email providers. The table also has rows for SendGrid and Mailgun, Slack, LLM integrations (MCP) and workflow integrations.
apollo.io/pricing · read 22 October 2026
03
Which email providers connect
The table row reads Gmail and Microsoft for Free and All Email Providers for the paid plans. The FAQ says free plans connect Gmail accounts only and that paid plans add Microsoft Office or any other provider.
apollo.io/pricing · read 22 October 2026
04
API access, described three ways
The FAQ says API access is available on Custom plans. The Free price card lists API Access, the paid cards list API Enrichment, and the API documentation's rate limit tables give limits for Free, Basic, Professional and Organization.
apollo.io/pricing; https://docs.apollo.io/reference/rate-limits · read 22 October 2026
05
API rate limits are per team
Limits apply per team, not per key, and each endpoint has its own counters across per-minute, per-hour and per-day windows. General limits: Free 50 a minute, 200 an hour and 600 a day. Basic and Professional 200, 400 and 2,000. Organization 200, 600 and 6,000. Higher limits need a request to Apollo Support.
docs.apollo.io/reference/rate-limits · read 22 October 2026
06
Enrichment and search have their own limits
Enrichment endpoints on paid plans allow 1,000 a minute with no hourly or daily limit, but credits still bound how much you can enrich. Search endpoints on paid plans allow 200 a minute, 6,000 an hour and 50,000 a day. MCP uses separate limits.
docs.apollo.io/reference/rate-limits · read 22 October 2026
07
What the API covers
The documentation index lists people and organisation search and enrichment, records such as accounts, contacts, deals and lists, sequences and outreach, an AI Assistant, workspace management, analytics and usage. It lists a Poll Webhook Result endpoint and no webhook subscriptions.
docs.apollo.io · read 22 October 2026
08
Extensions and MCP
The price cards list Prospecting, Gmail and Salesforce Extensions, and the home page names a Chrome Extension, Apollo Anywhere and an Apollo MCP. The home page describes the Chrome extension as getting verified emails and phone numbers while you work in your favourite tools.
apollo.io · read 22 October 2026
09
The integrations directory
The directory page shows 69 results across 3 pages. The 30 cards we could read are labelled Integration (13), Workflows (7) and Waterfall Enrichment (10), with Slack marked Recently Launched and Salesforce featured. Named tools include HubSpot, Marketo, Chili Piper, Clay, Claude, ChatGPT, Airtable, Asana, Google Sheets, Hunter.io and Findymail. Zapier is not mentioned.
apollo.io/product/integrations · read 22 October 2026
What Apollo.io does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Webhooks or Zapier named as an Apollo feature on the integrations page
- Plan requirements per integration on the directory page
- Which plan each comparison-table row, such as Slack or Pipedrive, applies to
- API rate limits for a Custom plan
Where the sources disagree
We report each version rather than pick one.
- Apollo's home page claims 200+ integrations, while the integrations directory page shows 69 results. The two may count differently, and we do not say which is right.
- Apollo's FAQ says API access is available on Custom plans, while the Free price card lists API Access and its documentation gives API rate limits for Free, Basic, Professional and Organization. We report all three.
- Apollo's FAQ says free plans connect Gmail only, while its comparison table lists Gmail and Microsoft for the Free column. We report both.
The numbers
Only what we could verify.
| Measure | Warmerly | Apollo.io |
|---|---|---|
| Integrations, API and LinkedIn | API and 16 mailbox-health webhooks on Agency; an MCP server on every plan. No CRM sync found. LinkedIn is $19 a month per account. | CRM integrations from Basic, with Salesforce and HubSpot named; a Chrome extension and an MCP. API access on Custom plans per its FAQ. |
| CRM integrations | None found | From Basic |
| API access | Agency plan, $179 a month | Custom plans per its FAQ |
| Webhook event types | 16, mailbox health only | Not stated |
| MCP server | Every plan | Apollo MCP named, plan not stated |
| $19 a month per account | Named as an integration | |
| API requests a minute | 60 a key by default, up to 120 | 200 a team on Basic, general limit |
| API requests a day | No daily cap stated | 2,000 a team on Basic, general limit |
| Webhook subscriptions | 10 a user | Not stated |
| Integrations claimed | Not stated | 200+ on the home page, 69 in the directory |
| Entry price of the plan that carries the API | $179 a month, Agency | $49 per seat a month on Basic, billed annually |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
If a CRM is in your daily work
Apollo is built to sit beside one. Warmerly would mean a CSV export or building on its API from Agency.
If you build your own tooling
Warmerly's API and webhooks are on Agency and its MCP server is on every plan, all documented for developers.
What the API limits mean in volume
Warmerly's 60 a minute is 3,600 an hour and 86,400 in 24 hours if you send at full pace, and 172,800 at the cap of 120. Apollo's general limit on Basic is 200 a minute but 2,000 a day per endpoint, so the day limit is reached in 10 minutes of full-speed calls. The daily window is the one that bites.
Search at volume on Apollo
Apollo's search limit on paid plans is 50,000 a day, 25 times the general 2,000. At 100 results per page, the documentation says organisation search costs 1 credit per page, so 50,000 calls could in theory use up to 50,000 credits, far above Basic's 2,500 a month. Credits, not the rate limit, are the real ceiling.
Webhooks are for health alerts, not for replies
Warmerly's webhooks carry mailbox health events only, delivered on a 5-minute sweep. Do not plan on them for opens, clicks or replies, and note an event that fails 3 tries is skipped. To act on replies you would poll the inbox endpoints, which are on the same Agency plan.
What the API costs to reach
Warmerly's API sits on a $179 plan, about 3.65 times Apollo Basic's $49 for one seat. The two are not like for like: the Agency plan also carries 100 mailboxes and 100,000 monthly email lookups, while some of Apollo's API endpoints spend credits.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You want an MCP server on every plan
- You want mailbox-health webhooks you can build on
- You want LinkedIn steps in the same sequence as email
- You want one signed webhook and key model you can read in the docs
Apollo.io
Apollo.io is the better fit if
- You need Salesforce, HubSpot or similar syncing with your outreach
- You want a Chrome extension for prospecting
- You want an API on entry paid plans, once you have confirmed which plan includes it
- You want workflow tools such as Clay or Airtable in a directory
Questions
Does Apollo.io integrate with my CRM?
Its pricing FAQ names Salesforce and HubSpot among its integrations, and the price cards list CRM Integrations from Basic.
Which Apollo plans include the API?
Its pages disagree. The FAQ says Custom plans, the Free price card lists API Access, and the documentation gives rate limits for Free, Basic, Professional and Organization. Ask Apollo before you build.
Does Warmerly work with Zapier?
We found no Zapier app. The docs say tools like Zapier can use an API key, which needs the Agency plan.
Can Warmerly send a webhook when someone replies?
No. Its 16 webhook event types are about mailbox health, such as score drops and auth failures, and do not include replies, opens or clicks.
Sources
- Apollo pricing page, rendered in a browser, plus its FAQ
- Apollo home page
- Apollo integrations page
- Apollo API documentation: rate limits
- Apollo API documentation index
- Warmerly plans and limits (product docs)
- Warmerly docs: webhooks, errors and rate limits, use with AI (MCP)
Apollo.io pages were read on 21 October 2026. Plans and wording change, so check the vendor's own page before you decide. Warmerly details come from the product as it runs today.
See it on your own mailbox.
Connect a mailbox. Warmerly runs alongside whatever you send from now, so you can compare before you move anything.
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