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Firstsales

Cold email that reaches the inbox

Deliverability
For AI agents
APILimited readiness
About

What is Firstsales

FirstSales handles the infrastructure layer of cold email — warming sender accounts, cleaning contact lists, monitoring inbox placement in real time, and configuring email authentication so outbound messages reach primary inboxes rather than spam. It's built for SDRs, founders, and agencies running cold outreach at volume, from small teams sending 30,000 emails a month up to mid-market operations pushing 500,000. The standout capability is unlimited sending accounts across all plans, which lets agencies and multi-brand operators scale without paying per seat or per inbox. AI personalization and sequencing with triggers and scheduling are included, reducing the manual work of building and managing campaigns. The honest limitation: native integrations are not documented, so teams relying on CRM sync or multi-tool workflows will need to lean on the API — which exists but carries limited agentic readiness.

Deliverability
Capabilities

Key features

Deliverability infrastructure

warmup, spam tests, and sender reputation

AI capabilities

AI-drafted personalised copy

Workflow

multi-step sequences, event-driven triggers, templates library

Our verdict

Vanderbuild take

For SDRs, founders, and cold email agencies that need deliverability infrastructure without paying agency rates, FirstSales covers the core stack — warm-up, list hygiene, authentication, and sequencing — at a price point that makes sense for SMBs and growth-stage teams. On the agentic side, an API is available, but agentic readiness is rated limited, meaning you'll hit friction before you can reliably orchestrate this inside an AI-driven outbound workflow — no MCP server is confirmed, and integration depth is unclear. At $28/month to start, the financial risk to test is low, and the workspace-based model means costs stay predictable as you add sending accounts; that said, expect to upgrade tiers as your contact volume grows past the Starter ceiling. The main gap we'd flag is native CRM integrations — none are documented, so if your team lives in HubSpot or Salesforce, plan for manual exports or API work to close that loop.

Mateusz Sekta
Founder, vanderbuild
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Our Resources

The wedge

Agentic stack profile

API
REST

Programmatic access available.

REST API — straightforward to call from any agent or workflow tool. Rate limits and auth vary by plan.

API docs →
Agentic readiness
Limited

Usable but with caveats — rate limits, brittle endpoints.

API exists but is rate-limited, brittle, undocumented, or hidden behind enterprise plans. Use with caution in production agent workflows.

Stack role
Deliverability

Where this tool slots into an agentic pipeline.

Plays the role of Deliverability in an agentic pipeline. Use it to keep email sending reputation healthy — warmup, spam tests.

Compare

Firstsales alternatives

Tools that solve a similar problem — compared at a glance.

Firstsales(this tool)
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Budget
$$
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Readiness
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winnr
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Budget
$$
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GTM Engineer, Founder
Readiness
Native
MCP
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Infraforge
Pricing
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Budget
$
Best for
SDR / BDR, Agency
Readiness
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REST
Answers

Frequently asked questions

Does Firstsales have a public API?

Yes — Firstsales ships a REST API. Docs: https://docs.firstsales.io/. Note the API is rate-limited or enterprise-gated, so plan integrations accordingly.

How much does Firstsales cost?

Firstsales: pricing is workspace-based, expect mid tier ($$) spend. Full pricing page: https://firstsales.io/pricing/.

Who is Firstsales best for?

Firstsales is built for SDR / BDR, Founder, Agency. Fits SMB (1-50), Mid-market (50-500)-sized teams.

How well does Firstsales fit an agentic sales stack?

Tier: Limited. An API exists but it's rate-limited, brittle, or enterprise-gated. Plan integrations carefully.