Best for · AI infrastructure for builders · Series A startups
Best AI infrastructure for builders for Series A startups.
Builders working with LLMs and agents need a different kind of catalog: composable, self-serve, OSS-friendly, priced per-token or per-query. Magpie covers vector DBs (Pinecone), inference (Together AI, Groq, Hugging Face), observability (Helicone, Langfuse), web search APIs (Tavily), and self-hostable model runners (Ollama, Replicate). Picks favour generous free tiers and OSS-first products. At this layer of the stack, lock-in is expensive. Series A is the scaling phase. The infrastructure for builders below sit in the mid-market sweet spot: substantive AI features, public APIs and MCP servers for agent-readiness, and clear price tiers that don't punish growth.
32 tools matched. Filtered to those that cover both axes.
Firecrawl
The web data API for AI
$16/mo·Seed → Growth
Sentry
Error tracking with an AI-native MCP for agents
Free·Seed → Growth
Anthropic MCP
The protocol itself, with reference servers
Free·Seed → Growth
Cloudflare
Edge platform with Code Mode MCP for infrastructure-controlling agents
Free·Seed → Growth
Composio
Hosted MCP server hub for 250+ apps
$49/mo·Seed → Growth
LlamaIndex
RAG and agent framework with managed cloud
$50/mo·Seed → Growth
Relevance AI
No-code multi-agent workforce builder
$29/mo·MVP → Growth
AWS MCP Servers
Official open source MCP servers for AWS
Free·MVP → Growth
Brave Search MCP
Web search MCP server for agents
Free·Seed → Growth
Crew AI
Open-source multi-agent framework
Free·Seed → Growth
GitHub MCP Server
GitHub's official MCP server for AI agents
Free·MVP → Growth
LangGraph
Multi-agent orchestration framework with state graphs
$39/mo·Seed → Growth
Microsoft MCP
Official catalog of Microsoft MCP server implementations
Free·MVP → Growth
MLflow
Open-source AI engineering platform for agents, LLMs and ML models
Free·MVP → Growth
Smithery
Registry and runtime for MCP servers
Free·Seed → Growth
Tavus
Build conversational video agents
$59/mo·MVP → Growth
E2B
Cloud sandboxes for AI agents
$150/mo·Seed → Growth
Pinecone
Reference vector database for RAG and semantic search — Starter tier is free up to 2GB
Free·MVP → Growth
Stack AI
Enterprise AI agent platform
Contact·Seed → Growth
Browser Use
AI agent that controls a real browser
Free·MVP → Growth
Hugging Face
The model hub the open-source AI ecosystem runs on — free Spaces, $9 PRO, $20/user Team
Free·Solopreneur → Growth
Speechify TTS API (Simba)
Simba TTS API at 300ms latency and $10 per 1M chars
Free·Seed → Growth
Browserbase
Web browsers for AI agents
$39/mo·Seed → Growth
Pydantic AI
Type-safe Python agent framework
Free·MVP → Growth
Replicate
Run, fine-tune, and deploy AI models with one line of code
Free·MVP → Growth
Clawvisor
Authorization layer for AI agents
Free·MVP → Growth
Hyperbrowser
Headless browser infrastructure for AI agents
$30/mo·Seed → Growth
Langfuse
Open-source LLM observability and evals — Hobby tier free, $29/mo Core, self-hostable
Free·MVP → Growth
Together AI
Cheap, fast inference for open models — Llama 3.3 70B at $0.88 per million tokens
n/a·MVP → Growth
Tinker
Fine-tuning API for open-source LLMs
n/a·Seed → Growth
BabyAGI
Experimental self-building autonomous agent framework
Free·MVP → Growth
SubQ
Sub-quadratic LLM for 12M-token reasoning
Contact·Seed → Growth
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