Reply.io API review
Best for teams that outgrow per-seat pricing
GET https://api.reply.io/v3/whoami Authorization: Bearer $REPLY_API_KEY # v3: 100/min, 3,000/hour, 150,000 per rolling 7 days # v1 and v2 are still live: 15,000 calls a month # that is the same API, 43x apart on quota
Reply.io is a multichannel sequencer, email plus LinkedIn plus calls and SMS, and it is the only sender in this directory whose price changes shape as you scale rather than just getting bigger. Below 10,000 active contacts you pay per user: $49 a month each at 1,000 contacts, rising to $89 at 5,000. At 10,000 contacts the per-user charge disappears and you pay $159 a month for unlimited users. A four-person team is cheaper on the bigger plan.
The second thing to understand is what Reply.io means by its numbers. An active contact is a unique person who received at least one outreach step in the billing month, and follow-ups to them are free, which is why the plans say unlimited emails. And the unlimited mailbox claim is governed by a fair usage policy that Reply actually publishes as a table: one mailbox per 40 active contacts.
The Reply.io API is the part most likely to catch you out, because there are two of them live at once and they are not close. The current version is v3, documented at docs.reply.io with proper rate limits. The older v1 and v2 are still working, still reachable at apidocs.reply.io, and allow 15,000 calls a month with ten seconds between them.
The rest of the category is in the Sending APIs listing.
Where the per-seat charge stops
The Email Volume slider is the main plan family, and it changes billing model partway up. These are the annual figures from Reply.io's own pricing page, with the monthly ones in brackets.
| Active contacts a month | Price | Users | Mailboxes included |
|---|---|---|---|
| 1,000 | $49 ($59) | Per user | 25 |
| 2,000 | $59 ($69) | Per user | 50 |
| 3,000 | $69 ($79) | Per user | 75 |
| 5,000 | $89 ($99) | Per user | 125 |
| 10,000 | $159 ($179) | Unlimited | 250 |
| 25,000 | $259 ($299) | Unlimited | 625 |
| 50,000 | $459 ($499) | Unlimited | 1,250 |
| 100,000 | $899 ($999) | Unlimited | 2,500 |
Above 100,000 contacts the slider says contact sales. The other plan family, Multichannel, inverts the meters: unlimited active contacts for $89 a user a month, but a fixed 10 mailboxes on annual billing and 5 on monthly. So the cheap family gives you unlimited mailboxes and meters contacts, and the expensive one gives you unlimited contacts and meters mailboxes. Which is right depends on whether your constraint is list size or sending capacity.
The arithmetic is worth doing because it points the opposite way to intuition. At 5,000 contacts you pay $89 per user, so two seats is $178 a month. At 10,000 contacts you pay $159 for unlimited seats.
Two users already cost more on the smaller plan, and a four-person team pays $356 for half the contacts. Anybody buying Reply.io for a team should start at the 10,000 tier and work down only if one person will ever log in.
Reply.io API pricing, plan by plan
Reply.io API pricing does not exist as its own line: the API is on every plan, including the 14-day trial, and what you are buying is the active contact allowance underneath it.
Email Volume, 1,000
- Unlimited mailboxes under fair usage, 25 at this tier
- Unlimited emails to active contacts
- 50 live data credits, 200 website visitor reveals
Email Volume, 10,000
- Unlimited users, no per-seat charge
- 250 mailboxes under the published ratio
- LinkedIn automation at $69 a month per account
Multichannel
- Unlimited active contacts
- 10 mailboxes annual, 5 monthly
- LinkedIn, calls, SMS and WhatsApp included
Agency Core
- Multiple client workspaces under one account
- Unlimited clients, users and mailboxes
- White label as an option
Jason, the AI SDR, starts at $500 a month and runs to $3,000 for 10,000 contacts. Reply.io also sells the sending infrastructure: a pre-warmed domain is $25 a year with three mailboxes at $15 each a month, fresh mailboxes are $5 a month, and any mailbox beyond the number your plan includes needs a $29 a month email account seat. Contact storage past 100,000 is $30 a month per additional 100,000.
Every sender in this category advertises unlimited mailboxes and every one of them applies some fair usage rule. Reply.io is the only one that prints the rule as a table, and the table is exactly one mailbox per 40 active contacts: 1,000 contacts gets 25, 100,000 gets 2,500. That is worth knowing in both directions. It is a real ceiling, so a team wanting 200 inboxes needs the 10,000 contact tier whether or not it needs 10,000 contacts. It is also a generous one, and far more honest than a claim with an unwritten limit behind it.
The version decides the quota
Reply.io API rate limits depend entirely on which version you call, and the gap is large enough to change an architecture. The current v3 publishes three windows; the deprecated v1 and v2 publish a monthly cap and a minimum gap between calls.
| Version | Limit | Scope |
|---|---|---|
| v3 | 100 per minute | Per user. Window starts on your first request. |
| v3 | 3,000 per hour | Per user. |
| v3 | 150,000 per 7 days | Rolling, not a calendar week. |
| v1 and v2 | 15,000 a month | Per user, and still the live limit on those versions. |
| v1 and v2 | 10 seconds between calls | Which works out at 6 a minute. |
| v3 reporting | Lower, unpublished | /v3/reporting/* and the sequence stats endpoints. |
What a 429 tells you
Readable, with one trap.
- Status 429 with Retry-After in seconds and application/problem+json.
- The detail names the window that broke, for example 150000 per 7d.
- GET /v3/rate-limits returns all three windows, usage and reset times in one call.
- Reporting endpoints can 429 before any of the general limits are reached.
Do not predict a 429 from the headers
They describe one window only.
- x-rate-limit-limit holds a period such as 7d, not a request count.
- The headers report the longest window that applies, so usually the weekly one.
- That means x-rate-limit-remaining can read 148,730 while the minute quota is spent.
- 429 responses carry only Retry-After, and none of the three headers.
This is the practical risk, not the numbers themselves. apidocs.reply.io is the older, better established host, it is what most links point at, and it documents v1 and v2 as working. They are working.
They are also capped at 15,000 calls a month with a ten second floor between requests, which is roughly 6 a minute against v3's 100, and they carry a deprecation notice rather than a date. If you inherit a Reply.io integration, check the base path before you check anything else: a build on /v1/ has 10% of the quota it could have, for no reason other than which page somebody opened first.
How to create a Reply.io API key
Reply.io uses Bearer token authentication on v3, with a per-user key from the app, plus a team-level key that can act as any member.
Getting the Reply.io API key
One per user.
- Log into Reply.io, open Settings, and copy the key from the API Key section.
- Send it as Authorization: Bearer YOUR_API_KEY on every v3 request.
- Confirm it with GET /v3/whoami, which returns the authenticated user.
- A missing or revoked token returns 401 with WWW-Authenticate: Bearer and an empty body.
The Master API Key
Beta, and team only.
- Available only with Team Edition on, or for organizations, and generated by the owner.
- Acts as the owner by default, or as a named member with X-User-Id or X-User-Email.
- Permissions follow the impersonated user, so it grants nothing extra.
- Rate limits are per user, so impersonation also moves which quota you spend.
Where the Reply.io API documentation lives
There are two sets of Reply.io API documentation and only one of them is current. v3 is at docs.reply.io on Mintlify, so every page returns Markdown if you append .md. The older v1 and v2 reference is a Postman collection at apidocs.reply.io, and it says on its own front page that both versions are outdated and unsupported.
| Surface | Where | What it answers |
|---|---|---|
| v3 overview | docs.reply.io | Base URL, auth, conventions, endpoint groups. |
| v3 rate limits | docs.reply.io/api-reference/rate-limits | All three windows, the headers and the 429 shape. |
| API base | api.reply.io/v3/ | Where current requests go. |
| v1 and v2 | apidocs.reply.io | Deprecated, still live, 15,000 calls a month. |
| Limits in the app | Support article, "existing limits in Reply" | The fair usage mailbox table and daily send caps. |
| Pricing for agents | reply.io/reply-io-pricing.txt | Every slider position as plain text. |
Errors use application/problem+json throughout, with a stable code in <resource>.<variant> form such as webHook.invalidEvent, and validation errors add an errors[] array keyed by JSON Pointer. Long jobs like bulk imports and email validation return 202 with a Location header pointing at /v3/background-jobs/{id}. Native CRM integrations cover Salesforce, HubSpot, Pipedrive, Copper, Close and Zendesk Sell.
Reply.io also ships an MCP server, and it is on the MCP page with the others in this directory.
Reply.io's own walkthrough of the API
Reply.io publishes this on its own channel, so it is Reply.io's account of Reply.io, not ours. It is here because a rate card cannot show you the thing moving, and a few minutes of the product is faster than any paragraph on this page at telling you whether the shape of it fits yours.
YouTube · Reply Reply API - The Full Power of Reply, Without Touching the UI 2:24 · Published May 2026Two minutes from Reply's own partnerships lead, pitched at developers: endpoints, webhooks, and Zapier, Make and n8n. One claim in it is Reply's rather than ours, 270 plus endpoints, so check their reference before you size anything on it. The MCP server it mentions is documented at docs.reply.io and is on the MCP page.
Published 28 May 2026 on Reply, the channel Reply.io's own pages link to, and read on 13 October 2026. Nothing in it is a source for a price or a limit on this page: every figure in the tables above comes from a Reply.io page.
Strengths and limits
Reply.io is the most honest rate card in this category and the most complete multichannel sequencer in it.
What it does well
- Unlimited users from the 10,000 active contact tier upward.
- The fair usage mailbox ratio is published as a table, which nobody else does.
- Follow-ups are free: the meter is unique contacts touched, not emails sent.
- API on every plan including the 14-day trial, with no tier gate.
- v3 publishes three rate limit windows, a usage endpoint and a readable 429.
- Error codes are stable and machine readable, with JSON Pointer validation detail.
- Email, LinkedIn, calls, SMS and WhatsApp in one sequence.
- A plain text rate card at reply.io/reply-io-pricing.txt, written for agents.
Where it falls short
- Two live API versions 43x apart on monthly quota, and search favors the old one.
- v1 and v2 carry a deprecation notice with no date attached.
- The rate limit headers report one window, so they cannot predict a 429.
- Reporting endpoints are throttled lower than the published figures, unstated.
- Multichannel gives 10 mailboxes on annual billing and only 5 on monthly.
- LinkedIn automation is a $69 a month per account add-on on Email Volume plans.
- An OAuth connection to the MCP server gets the full tool catalog, so limiting an agent means using a scoped personal API key instead.
- No free tier.
Where Reply.io data comes from, and what you may do with it
The question that arrives late and expensively is not how good the data is, it is who is allowed to hold it. These are the fields each one returns, the coverage it claims and the compliance it publishes.
| Provider | Fields returned | Coverage | Compliance | Redistribution |
|---|---|---|---|---|
| Reply.io | Work email, LinkedIn profile, CRM records | Global | GDPR DPA | Not stated |
None of these states a redistribution position on its pricing or docs pages. Internally that never matters. Put the rows in something your customers can see and it becomes the question your legal team asks first.
Two practical notes that apply to every provider on this page. A compliance badge describes the vendor, not your use of it, so a GDPR DPA does not give you a lawful basis for the outreach you send. And every one of these vendors runs its own opt-out, which means a person who asks you to delete their record has to be removed from your copy as well as from theirs.
If Reply.io is not the answer
Four providers in the Sending APIs listing that solve the same problem differently. Each one is a trade, and the trade is named.
Smartlead
$39/moThe volume sender. No per-seat charge at all, unlimited mailboxes with no published ratio, and 90,000 sends on the first plan that carries the API.
Instantly
$47/moCheapest way to get an API against a sender, at $47 with 100 requests a second. Unlimited mailboxes and warmup on the same plan.
Dripify
$39/user/mo annualIf LinkedIn was the half you were paying $69 an account for. One seat per LinkedIn profile from $39, with the API from Pro.
Salesloft
Quote onlyThe enterprise end of the same job, with a well documented cost-per-minute API. No published price, so expect a sales conversation.
The full set, organized by the reason people leave, is on the Reply.io alternatives page.
Reply.io against the obvious rival
Same rate cards, read side by side, with the arithmetic done on a worked volume rather than left to you: Reply.io vs Woodpecker, Reply.io vs Salesloft and Instantly vs Reply.io. Every pairing in the directory is on the compare hub.
Reply.io vs Woodpecker
CompareOne publishes a slider with a pricing cliff, the other has no plans at all and sells the API as a $20 add-on.
Reply.io vs Salesloft
CompareEvery price published against none, and the only sales engagement API here that meters by the minute.
Instantly vs Reply.io
CompareUnlimited mailboxes with no stated ceiling against unlimited mailboxes with a published ratio.
Before you build against it
Four things to settle first, each one read off Reply.io's own pages. The ticks are remembered in this browser, so you can come back to a half-finished integration.
Who should actually buy this
Buy Reply.io if you want one tool running email and LinkedIn together and you have more than one person using it. The pricing cliff at 10,000 active contacts is the whole argument: above it you pay a flat $159 a month for unlimited users and 250 mailboxes, which is cheaper than two seats on the tier below and far cheaper than per-seat multichannel tools. Teams are where this product is priced to win, and the published mailbox ratio means you can size the infrastructure before you buy rather than after.
Skip it if you are one person sending to a small list. At 1,000 contacts you are paying $49 a month for an allowance you will not fill, and the single-operator end of this category is better served by Smartlead or Instantly, where the money buys sending volume instead of multichannel breadth. Skip the Multichannel family too unless LinkedIn volume is genuinely the point, because capping mailboxes at 10 undoes the deliverability advantage the Email Volume plans give you.
On the API, the only decision that really matters is the base path. Build on /v3/ and you get 100 requests a minute, 150,000 a week, a usage endpoint and errors you can branch on. Inherit something on /v1/ and you have 15,000 calls a month and a ten second floor between them, which is enough to make a nightly sync look like a platform limitation when it is really a URL. Check that first, then stop trusting the rate limit headers to predict anything, because they only ever describe the weekly window.
Multichannel sequences are only as good as the reason to send them.
Reply.io will run the sequence. Frontal builds the signal that decides who enters it and what the first line says, inside your own stack.
Worked with 300+ companies. A senior operator runs your account.
Nothing worth quoting yet
The harvest this site runs searches Reddit for Reply.io threads where the API itself is the subject, and it has not come back with a quote that survives the transcription rules yet. When one does, it lands here. Nothing on this page leans on an unquoted paraphrase.
Reply.io API, answered
Is the Reply.io API free?
No. No free tier. 14-day trial with API access and 300 active contacts.
How much does the Reply.io API cost?
Reply.io starts at $49/user/mo. Billing is subscription and per seat. Read from Reply.io's own pricing page on 8 October 2026.
What are the Reply.io API rate limits?
v3: 100 req/min, 3,000/hour, 150,000 per rolling 7 days, per user. v1 and v2: 15,000 a month.
How do I get a Reply.io API key?
Bearer token on v3. A team Master API Key can impersonate a user. The current steps are in Reply.io's own documentation, which is authoritative on anything that has changed since 8 October 2026.
Does Reply.io have an MCP server?
Yes, at https://mcp.reply.io/. It is listed with the others on the MCP page.