You've built your cold email workflow inside Instantly.
The campaigns are running, leads are coming in, and replies are getting managed.
Now you want to take it a step further. You want to connect Instantly to your CRM, trigger actions based on campaign events, or build a custom automation that fits the way your team actually works.
That's where the Instantly API comes in.
The Instantly API lets you tap into your campaign data, manage leads, and integrate Instantly with the rest of your tech stack, without having to do everything manually inside the platform. For developers, RevOps teams, and agencies building scalable outreach systems, this kind of programmatic access can be a game changer.
But not everything about the Instantly API is straightforward.
For starters, there are two versions to navigate (V1 and V2), certain features are locked behind higher-tier plans, and the API has some real limitations that could affect how well it fits your workflow.
We at Salesforge decided to dig in and test it ourselves.
In this review, we break all of it down for you. We'll walk you through what the Instantly API actually does, how to get started, what's available across key endpoints, where it falls short, and who it's really built for.
Let's get into it.
Instantly API vs Salesforge API: Comparison At a Glance
Before we get into the full breakdown, here’s a quick side-by-side look at how Instantly’s API stacks up against Salesforge so you can get the lay of the land right away.
Both platforms allow integration with multiple services, making it easy to streamline workflows by connecting various tools and platforms for more efficient data management and real-time communication.
Both Instantly API and Salesforge support outreach campaigns, but they differ in their approach and channel support—Instantly focuses on email marketing, while Salesforge enables multi-channel lead engagement across email and LinkedIn.
As you can see, Instantly’s API does the job for email-focused workflows, but Salesforge brings a lot more to the table, especially if you’re thinking beyond just cold email.
We’ll dig into all of this in detail throughout the review.
What Is the Instantly API?
Instantly is a cold email outreach platform built for sales teams, agencies, and founders who want to send high volumes of personalized emails at scale.
It handles everything from campaign creation and lead management to email warm-up and inbox rotation. With API integrations, you can also update or change lead status automatically through platforms like Zapier and Make.com, streamlining your lead follow-up processes.
But if you want to go beyond what the platform’s interface offers, connecting Instantly to your CRM, automating workflows, or building custom integrations, that’s where the Instantly API comes in.
The Instantly API is a RESTful interface that lets developers and technical teams interact with Instantly’s data and features programmatically. API V2 adheres to REST API standards with a few minor exceptions.
Instead of manually logging into the dashboard to check campaign stats, add leads, or update email accounts, you can do all of that directly through API calls. The Instantly API eliminates manual steps such as data download, CSV formatting, and manual upload, streamlining the process of importing leads.
This opens the door to building custom workflows, syncing data with external tools, and automating actions that would otherwise require manual effort inside the platform. Personalized workflows enabled by the API can help improve reply rates by optimizing messaging and engagement.
It’s worth noting that the Instantly API is focused exclusively on email outreach.
There’s no LinkedIn or multi-channel support baked in at the API level.
If your outreach strategy goes beyond cold email, that’s a limitation you’ll want to keep in mind.
Instantly API V1 vs. V2: What Changed?
If you've been using the Instantly API for a while, or you're just getting started and noticed there are two versions floating around, here's what you need to know: V1 is on its way out, and V2 is the version you should be building on.
API V1 was deprecated on January 19, 2026, and V2 is now the official stable version.
If you're still running integrations on V1, you need to migrate.
The good news is that third-party tools like Zapier won't be affected. Integrations that rely on API V1 like Zapier will continue working without disruption, as the deprecation only applies to users building directly on V1.
But if you have custom-built workflows hitting V1 endpoints, those will need to be updated.
Here's a clear breakdown of exactly what changed between the two versions:
One important thing to be aware of: V2 has zero compatibility with V1.
This isn't a minor version bump where things mostly carry over.
It's a ground-up rebuild, which means if you're migrating, you'll need to remap your endpoints, update your authentication, and account for the new naming conventions throughout your codebase.
For teams using Clay, there's a specific heads-up worth noting.
For any actively used columns in Clay that connect to Instantly, you'll need to create a new column from scratch rather than duplicating the original, since the V1-based columns won't carry over cleanly.
The bottom line: if you're starting fresh, go straight to V2. If you're migrating from V1, plan for it to take some actual engineering time. This isn't a quick find-and-replace job.
How to Get Started with the Instantly API
Getting up and running with the Instantly API is straightforward, but there are a few things you need to have in place before you make your first API call.
You will need to obtain your Instantly API key from your Instantly account and use it to create a connection with other services for authentication and integration.
Here’s exactly what you need to do.
Step 1: Make Sure You're on the Right Plan
API access is available on Instantly's paid plans.
Before anything else, confirm your current plan includes API access.
If you're on a lower-tier plan and can't find the API section in your settings, a plan upgrade is likely what's standing between you and your API key.
Step 2: Generate Your API Key
To get your Instantly API key, go to your Instantly Dashboard, navigate to Settings → Integrations, and look for the API section.
Here, you can generate a new V2 Instantly API key.
After generating the key, you will need to enter your Instantly API key when connecting Instantly to third-party platforms, such as Make, to authenticate and establish the integration.
Once generated, store your Instantly API key immediately in your secrets manager or as an environment variable — never hardcode it directly into your codebase.
One important note: you will need a new API key specifically for V2. Your old V1 key will not work on V2 endpoints.
Step 3: Understand API Scopes
Instantly V2 introduces API scopes, which give you granular control over what each API key is allowed to do.
This means you can create separate keys for different use cases.
For example, a read-only key for your reporting dashboard and a key with full access for your lead management workflow. It also makes your setup more secure, since you can revoke individual keys without affecting the rest of your integrations.
Step 4: Authenticate Your Requests
Instantly API V2 uses Bearer token authentication for all requests.
Every API call you make needs to include your token in the Authorization header like this:
Authorization: Bearer <YOUR_TOKEN_HERE>
Step 5: Explore the Interactive Docs
Before you start building, take some time to explore the documentation.
The entire API V2 documentation is interactive and can be tested directly from the browser.
On the right side of every endpoint, you'll see a box with an example request, and you can click the "Try it" button to send a real request to the server without writing a single line of code.
This is a great way to understand what each endpoint does and what kind of response to expect before you start integrating.
Once you've completed these steps, you're ready to start building.
What You Can Do with the Instantly API
The Instantly API V2 gives you programmatic access to most of what you'd do inside the platform. But with the ability to automate it, integrate it, and scale it.
Here's a breakdown of the key functional areas and what you can actually do with each one.
Campaign Management
Campaign management is the core of what the Instantly API offers.
You can create campaigns programmatically, set up schedules, define sending windows, configure daily send limits, and manage sequences, all without touching the Instantly dashboard.
You can also pause, resume, and delete campaigns via API calls, which is especially useful if you're running automated logic that needs to respond to external triggers. Pull analytics for a single campaign or all campaigns at once by specifying the campaign ID or leaving it empty to retrieve aggregate data.
Lead and Contact Management
The API gives you solid control over your leads and lead lists.
You can create and manage lead lists, add leads to campaigns programmatically, move leads between campaigns based on CRM stage changes, and apply labels to segment them.
You can also manage block lists through the API, which helps you maintain hygiene across your outreach by suppressing risky or unsubscribed contacts before they ever make it into a campaign.
Email Account Management
You can retrieve information about your connected email accounts, map them to specific campaigns, and use custom tags to organize and filter accounts across your workspace.
This is particularly useful for agencies managing outreach across multiple clients and domains.
Inbox and Reply Data
One of the most valuable things the API unlocks is access to your reply data.
You can pull reply outcomes programmatically, route positive replies to the right rep automatically, trigger follow-up actions based on reply sentiment, or stream reply events into your CRM without manual copy-paste.
Analytics and Reporting
The analytics endpoints let you pull campaign performance data directly into your own dashboards or reporting tools.
You can pull open rates, click rates, bounce rates, and reply counts into a unified sales dashboard alongside your CRM data, or stream Instantly events to your data warehouse for multi-touch attribution modeling.
Webhooks for Real-Time Events
Webhooks are where the Instantly API really starts to shine for real-time automation, but there's a catch we'll cover in the limitations section.
When you do have access, the supported event types include email sent, email opened, email link clicked, reply received, email bounced, lead unsubscribed, campaign completed, account error, and lead neutral.
This means you can build automations like sending a Slack alert when a high-intent reply comes in, pausing a campaign the moment a bounce threshold is crossed, or pushing a lead into a new sequence the instant they respond.
It's powerful stuff, if you're on the right plan.
Instantly API Pros & Cons
The Instantly API has a lot going for it, but it also comes with some limitations that could affect your decision.
Here’s a clear breakdown of both sides.
Instantly API Pros
- API Access on All Paid Plans: You don't need to be on an enterprise tier to get API access. Instantly includes it across all paid Email Outreach plans, which makes it accessible for smaller teams and solo operators who want to start building automations early.
- Interactive V2 Documentation: The V2 docs let you test endpoints directly in the browser before writing a single line of code. This makes it significantly faster to understand what each endpoint does and what kind of response to expect — a big time saver during the build phase.
- Granular Security Controls: Bearer token authentication combined with API scopes means you can control exactly what each key is allowed to do. You can create separate keys for different workflows and revoke them individually without affecting the rest of your integrations.
- Full Campaign and Lead Management: You get programmatic access to campaign creation, lead list management, email account management, and blocklist control — covering the core of what most outreach automation workflows need.
- Wide Webhook Event Library: When you do have access, the webhook event types are comprehensive — covering email sent, opened, clicked, replied, bounced, unsubscribed, and more. This gives you plenty of triggers to build real-time automations around.
- No-Code Automation Support: Native support for Zapier and Make.com means teams that don't want to write custom code can still connect Instantly to their broader stack without developer involvement.
Instantly API Cons
- Webhooks Are Plan-Gated: Real-time webhook access is only available on the Hypergrowth plan and above. If you're on a lower tier and need event-driven automation, you'll have to upgrade or find a workaround.
- V1 to V2 Migration Is Disruptive: There's zero compatibility between V1 and V2. If you've already built integrations on V1, migrating isn't a quick fix — it requires remapping endpoints, updating authentication, and reworking naming conventions throughout your codebase.
- Email Only — No Multi-Channel Support: The API is built exclusively around email outreach. There's no LinkedIn, SMS, or any other channel at the API level, which limits its usefulness if your outreach strategy goes beyond cold email.
- Limited Native Integrations: Outside of HubSpot, Salesforce, and Pipedrive, the native integration library is thin. For most other tools, you'll need to build a custom connection or route everything through middleware like Zapier or Make.
- Shallow Lead Management: Lead management at the API level lacks the depth you'd get from a dedicated CRM or enrichment tool. There's no built-in enrichment, scoring, or advanced segmentation available programmatically.
- Costs Add Up Quickly: While the entry-level pricing is competitive, important features like webhooks are gated behind higher plans. As your needs grow, so does the price — and not always in a predictable way.
Instantly API Pricing
Understanding what you actually pay for API access with Instantly requires a closer look at their pricing structure because it’s not as simple as picking one plan.
Using data-driven prospecting tools like Instantly can help B2B companies increase their sales and overall revenue growth by improving outreach and lead generation.
Instantly uses a modular approach with separate pricing for different products: Outreach (sending emails), SuperSearch (finding leads), CRM, and Website Visitors.
Each of these is a separate subscription, which means your real monthly bill can look very different from the advertised starting price.
Here’s a breakdown of Instantly’s Outreach plans and what each one includes from an API perspective:
Instantly API Integrations
Instantly gives you several ways to connect your outreach data with the rest of your tech stack. Integrating multiple services can streamline workflows, simplify data management, and improve efficiency through unified APIs and real-time communication.
Here’s how each integration path works and what to expect from each one.
Native CRM Integrations
Instantly offers native connections to HubSpot, Pipedrive, and Salesforce directly from the platform.
These connections let you import contact lists from your CRM into Instantly campaigns and keep your outreach aligned with your existing pipeline.
However, there’s an important limitation to be aware of here: Instantly’s native HubSpot integration currently focuses on exporting leads from HubSpot into Instantly, mapping fields and enrolling contacts into outbound campaigns.
Activity data like opens, clicks, and replies doesn’t automatically flow back into your CRM natively. One-way data synchronization like this can lead to inaccuracies and follow-up issues, since updates in Instantly are not reflected in your CRM.
For true two-way sync, you’ll need a third-party connector like OutboundSync or a custom-built solution using the API and webhooks.
Zapier and Make.com
For teams that prefer no-code automation, Zapier connects Instantly to over 8,000 apps, and Make.com supports over 2,500 integrations.
Common workflows include triggering a CRM task when a reply is received, posting a Slack alert when a lead is marked as interested, updating contact records on bounces, and adding new leads from Google Sheets directly into a campaign.
Zapier uses a task-based billing model, while Make.com is operation-based and is transitioning to a credits model.
Clay
Clay integrates with Instantly to let you build enrichment waterfalls, verify emails, and use Claygent to pull research and personalization data, which then feeds directly into your Instantly campaigns.
This is one of the more powerful combinations in the outbound stack, letting you enrich and personalize leads at scale before they ever hit a campaign sequence.
OutboundSync
For teams that need reliable bidirectional CRM sync, OutboundSync is the go-to connector.
It logs Instantly send, reply, and status events into Salesforce or HubSpot in near real time, giving your sales team a complete activity timeline inside the CRM without any manual data entry.
Developer Integrations (API + Webhooks)
For teams that need full control, API V2 and webhooks let you create contacts, launch campaigns, and pull analytics programmatically.
To authenticate API and webhook integrations, you will need to use your Instantly API key, which establishes a secure connection between Instantly and third-party platforms.
This is the right path for agencies and RevOps teams building custom automation logic that goes beyond what Zapier or native connectors can handle.
Just keep in mind the plan requirements. Webhooks are Hypergrowth and above only.
Instantly API Limitations
The Instantly API covers the basics well, but once you start pushing it beyond standard use cases, the cracks start to show.
Here are the five key limitations you need to know about before you commit to building on it.
Minimal Native Integrations
Instantly connects natively to HubSpot, Salesforce, and Pipedrive and that's about it.
For most teams, that sounds fine on paper, but the reality is that these native connections are fairly shallow.
There's also no native connection to enrichment tools, lead scoring platforms, or data warehouses. While the integrations library is solid on the whole, it would benefit from tighter connections to enrichment tools and lead scoring tools.
If your stack goes beyond the three supported CRMs, you're looking at building custom integrations yourself or relying on Zapier and Make.com to fill the gaps.
Webhook Plan Gating
Webhooks are one of the most powerful features in the Instantly API.
They let you build real-time automations that respond to email events as they happen.
The problem is that webhook access is not available on the base Growth plan and only becomes available on the Hypergrowth plan and above.
That means you're paying at least $97 per month just to unlock real-time event triggers. For smaller teams or solo operators who don't need the full Hypergrowth feature set, being forced up to that tier just for webhooks is a frustrating and expensive trade-off.
Rate limits
The Instantly API enforces a rate limit and returns a 429 Too Many Requests error when you exceed it, requiring exponential backoff, starting at 1 second and doubling with each retry, before you can continue making requests.
For standard use cases this is manageable, but if you're building high-frequency automations that need to process large volumes of leads or campaign events in real time, these limits can become a bottleneck fast.
The workaround is to architect your system with rate limiting in mind from the start.
It's doable, but it adds engineering overhead that you wouldn't have to deal with on a more permissive API.
No Multi-Channel Support
This is perhaps the biggest structural limitation of the Instantly API.
The entire platform — and by extension, its API — is built around email.
There's no LinkedIn outreach, no SMS, no calling, and no multi-channel sequencing at the API level. If your approach requires native multichannel capabilities, Instantly might not align with your needs.
For teams that want to orchestrate email and LinkedIn touchpoints together, the Instantly API simply can't take you there.
Limited Lead Management at API level
While you can create lead lists, add contacts to campaigns, and manage block lists through the API, the depth of lead management available programmatically is limited compared to what you'd expect from a modern sales engagement platform.
There's no native enrichment, lead scoring, or segmentation logic available at the API level.
If you want to build dynamic, behavior-driven lead management workflows, you'll need to layer on additional tools, which adds both cost and integration complexity.
Who Should (and Shouldn't) Use Instantly API?
The Instantly API is a capable tool, but it's not the right fit for everyone.
Here's a straightforward breakdown of who will get the most out of it, and who should probably look elsewhere.
Who Should Use the Instantly API
You're a good fit for the Instantly API if you fall into one of these categories:
- Agencies running email outreach at scale: For agencies scaling outreach, Instantly's API manages unlimited inboxes on a flat fee with no per-email charges or separate warmup tools.
- Developers and RevOps teams building custom workflows: If you need accurate activity data in your CRM, unified reporting, or routing that matches your sales rules, you need API and webhook access.
- Sales teams that live and die by email: If cold email is your primary outreach channel and you want to connect it tightly to your CRM and reporting stack, the Instantly API does that job well.
Who Shouldn't Use the Instantly API
- Teams that need multi-channel outreach: If your sequences need to include LinkedIn touchpoints alongside email, the Instantly API won't get you there. Teams prioritizing LinkedIn and email multichannel outreach will find that Instantly doesn't align with those needs.
- Smaller teams on tight budgets: If you want API access plus webhooks but don't need everything else that comes with the Hypergrowth plan, you're going to be paying for a lot of features you won't use.
- Teams that need deep lead management: If your workflow requires native lead enrichment, behavior-based scoring, or dynamic segmentation at the API level, Instantly will leave you wanting more.
- Teams planning to build enterprise-grade integrations: Cold email platforms that offer robust API and webhook integrations for technical teams wanting to build custom workflows are better suited for power users who need full API control at high volumes.
Best Instantly API Alternative: Salesforge API
If you've read through the Instantly API limitations and found yourself nodding along, you're not alone.
The platform does a solid job for email-focused automation, but for teams that need more channels, more infrastructure control, more depth at the API level, it starts to feel like a ceiling.
That's exactly where Salesforge comes in.
Salesforge is a multichannel outreach platform that blends human efforts with AI-powered automation to help sales teams build more pipeline at a lower cost.
It's not just a cold email tool with an API bolted on. It's a full outreach stack built from the ground up to handle everything from infrastructure and warm-up to lead generation, multi-channel sequencing, and AI-driven personalization, all under one roof.
A Complete Outreach Stack, Not Just a Tool
One of the biggest differences between Salesforge and Instantly is the depth of the stack behind it.
The Forge Stack is built as a closed-loop outreach engine where infrastructure flows into warm-up, warm-up flows into lead generation, and leads flow into multi-channel outreach, all synced automatically without any manual effort.
Here's what that Forge Stack looks like in practice:
- Salesforge — The core outreach platform where you build and manage multi-channel sequences combining email and LinkedIn.
- Mailforge — Shared email infrastructure with automated DNS setup, ideal for teams scaling fast or managing higher complaint volume.
- Infraforge — Private email infrastructure with dedicated IPs, multi-IP provisioning, pre-warmed mailboxes, and its own API for programmatic infrastructure management.
- Warmforge — Every Salesforge plan includes Warmforge Premium, giving you access to advanced warm-up logic, placement testing, and inbox health monitoring — all without extra cost.
- Leadsforge — A lead generation engine that goes beyond basic data pulls, letting you generate lookalike audiences, extract competitor followers, qualify leads using intent signals, and surface buying indicators before outreach even begins.
- Primeforge — Google Workspace and Microsoft 365 mailboxes with US-based IPs, designed for ESP matching to boost primary inbox placement.
- Agent Frank (AI SDR) — Salesforge's AI Sales Development Representative that finds prospects, writes tailored outreach, follows up, and books meetings — and with multi-channel enabled, engages prospects on both email and LinkedIn.
Multi-Channel Outreach Built In
Unlike Instantly, which is limited to email at the API level, Salesforge lets you run multi-channel campaigns combining email and LinkedIn from a single dashboard, with unlimited mailboxes and LinkedIn senders, built-in AI personalization, deliverability protection, and autonomous AI SDRs.
This means your outreach sequences can include LinkedIn connection requests, profile visits, and messages alongside email touchpoints, all managed from one place, not cobbled together from multiple tools.
API and Integrations That Actually Scale
Salesforge offers an API to allow for virtually unlimited integrations.
On the integrations side, Salesforge connects with tools like Slack, Salesforce, Clay, and HubSpot. Plus, you can also plug in via Zapier, webhooks, or the Salesforge API to connect virtually any app.
The integrations library includes Folk CRM, Attio, Databar, Persana, Sendspark, and more, which gives you a much broader native stack than Instantly offers out of the box.
For teams that are serious about outreach at scale and want an API-connected stack that doesn't require duct-taping five different tools together, Salesforge is the most complete option on the market right now.
Final Verdict: Is the Instantly API Worth It?
So after going through everything, here's the honest answer: it depends on what you're trying to build.
The Instantly API is a solid choice if cold email is your primary outreach channel and you need programmatic control over your campaigns, leads, and inbox data.
But the moment you need anything beyond email, Instantly starts to feel limiting.
If you're at that ceiling right now or you can see yourself getting there soon, Salesforge is the smarter long-term bet.
You get API access at a lower plan tier, multi-channel outreach combining email and LinkedIn, a full infrastructure stack through Mailforge, Infraforge, Warmforge, and Primeforge, and an AI SDR in Agent Frank that can run your outreach autonomously.
The bottom line: if Instantly's API meets your current needs, it's a perfectly capable option. But if you're thinking about where your outreach stack needs to be six months from now, Salesforge gives you a lot more room to grow.
Sign up on Salesforge for a free 14-day trial and experience the difference yourself.
FAQs
1) What is the Instantly API used for?
The Instantly API gives you programmatic access to your Instantly account so you can manage campaigns, leads, email accounts, and inbox data without using the dashboard manually.
2) Which Instantly plan includes API access?
API access is available on all Email Outreach plans as of the latest update. However, if you need webhooks for real-time event triggers, you'll need to be on the Hypergrowth plan ($97/month) or above. The Growth plan does not include webhook access.
3) What authentication does the Instantly API use?
The Instantly API V2 uses Bearer token authentication. Every API call needs to include your token in the Authorization header as Authorization: Bearer <YOUR_TOKEN_HERE>. You can create multiple API keys with different scopes and revoke them individually for better security management.
4) Does Instantly support multi-channel outreach via API?
No. The Instantly API is email-only. There's no LinkedIn outreach, SMS, or multi-channel sequencing available at the API level. If your outreach strategy requires multiple channels, you'll need to look at a platform like Salesforge, which supports both email and LinkedIn from a single API-connected workflow.
5) What's the best alternative to the Instantly API?
If you need more than email-only outreach, deeper deliverability infrastructure, or a more complete API-connected stack, Salesforge is the strongest alternative. It offers API access at a lower plan tier, multi-channel outreach combining email and LinkedIn, a complete sales outreach stack.
