Fiber
Sales and recruiting data, built for agents
What is Fiber
Fiber AI provides data APIs that let sales and recruiting agents search across 850M+ professionals and 40M+ companies, enrich contact records in real time, and verify emails through four layers of bounce detection. It's built for SDRs, BDRs, GTM engineers, and founders at mid-market and enterprise companies who need programmatic access to prospect data without hitting LinkedIn's walls. The standout capability is its ability to identify companies by specific promotion patterns, headcount growth trajectories, or accelerator funding history — filters that most prospecting databases don't expose at the API level. The MCP server makes it directly callable by AI agents, which is rare in this category. That said, at $300–$2,400/month on a credit-based model, teams with low or unpredictable outbound volume may find the cost structure hard to justify before they've validated their ICP.
Key features
searchable B2B contact + company directory
autonomous multi-step actions, per-prospect AI research
verified emails, mobile phones, intent signals, real-time enrichment
official SDK
event-driven integrations
Vanderbuild take
Fiber AI sits at the intersection of prospecting database, data enrichment, and email finder — and it's one of the few tools in this category built from the ground up for SDRs, GTM engineers, and founders who want to drive outbound from code, not just a UI. If you're serious about agentic outbound, this is non-negotiable: the native MCP server makes it a first-class orchestration layer for AI agents, not an afterthought bolted on via webhook. Pricing starts at $300/month on a credit model, but the tiers scale to $2,400/month for enterprise volume — expect procurement involvement if you're running this at scale. The honest limitation is that the credit-based billing, where you only pay for successful data calls, sounds clean but can get unpredictable as query volume grows, and teams without a dedicated GTM engineer may struggle to extract full value from the API surface without significant setup time.
Agentic stack profile
MCP serverYesLive MCP server — agents can call this tool directly.
The MCP server connects LLMs and agents to Fiber AI's database of over 40 million companies and 850 million people.
Open MCP →APIRESTProgrammatic access available.
REST API — straightforward to call from any agent or workflow tool. Rate limits and auth vary by plan.
API docs →Agentic readinessNativeBuilt for agents from the ground up.
MCP server + agent-friendly API + at least one autonomous workflow out of the box. The bar for 'Native' is high — only a handful of tools currently qualify.
Stack roleData source · EnricherWhere this tool slots into an agentic pipeline.
Plays the role of Data source + Enricher in an agentic pipeline. Use it to source contacts, companies, and the raw inputs an agent needs to act; add firmographic, technographic, and signal data to a lead row on the fly.
Fiber alternatives
Tools that solve a similar problem — compared at a glance.
- Pricing
- Custom
- Budget
- $$$$
- Best for
- SDR / BDR, GTM Engineer
- Readiness
- Native
- MCP
- Yes
- API
- REST
- Pricing
- Freemium
- Budget
- $$
- Best for
- SDR / BDR, Account Executive
- Readiness
- Native
- MCP
- Yes
- API
- REST
- Pricing
- Seat-based
- Budget
- $$$$
- Best for
- RevOps, GTM Lead
- Readiness
- Native
- MCP
- Yes
- API
- REST
Frequently asked questions
Does Fiber have an MCP server?
Yes — Fiber exposes a Model Context Protocol server. The MCP server connects LLMs and agents to Fiber AI's database of over 40 million companies and 850 million people. See the MCP docs at https://docs.fiber.ai/article/using-mcp-in-llms.
Does Fiber have a public API?
Yes — Fiber ships a REST API. Docs: https://api.fiber.ai/docs.
How much does Fiber cost?
Fiber: pricing is custom, expect enterprise tier ($$$$) spend. Full pricing page: https://fiber.ai/pricing.
Who is Fiber best for?
Fiber is built for SDR / BDR, GTM Engineer, Founder. Fits Mid-market (50-500), Enterprise-sized teams.
How well does Fiber fit an agentic sales stack?
Tier: Native. Has both an MCP server and an agent-friendly API — drops into an agentic stack with minimal glue code.