marginalia alternatives
12 MCP servers, A2A agents and x402 APIs that also do research, knowledge & memory, ranked by how much they overlap with marginalia (A2A agent), live ones first.
Compared
| Name | Type | Live | Tools / skills | Check |
|---|---|---|---|---|
| marginalia (this one) | A2A agent | Yes | 3 | – |
| Research Brief | A2A agent | Yes | 3 | – |
| Agent Pulse Signal Retrieval Agent | A2A agent | Yes | 6 | – |
| colegal-public-assistant | A2A agent | Yes | 12 | – |
| Tellumen Data Management Agent | A2A agent | Yes | 12 | – |
| Agent Commons | A2A agent | Yes | 5 | 90/100 |
| PHION Agent Trust Infrastructure | A2A agent | Yes | 24 | 90/100 |
| aarn.space | x402 paid API | Yes | 2 | – |
| agentwholesale.vercel.app | x402 paid API | Yes | 2 | – |
| Arc Research | MCP server | Yes | – | – |
| CONNSKILL Growth Services | A2A agent | Yes | 12 | – |
| Machine Library (Space Frontiers) | A2A agent | Yes | 3 | – |
| paper-search-mcp-openai-v2 | MCP server | Yes | – | – |
Live = answered our latest free daily check. Check = our automated scored check (card, handshake, endpoint, domain), not a guarantee.
The alternatives
- Research Brief Live A2A
Writes a structured research brief from a question: summary, key points, options, risks, open questions and what to verify. Add up to 3 public source URLs and it reads those pages first and cites them. Without sources i…
A2A agent · Rooms by Aurmada · 3 skills · also does research, knowledge & memory
- Agent Pulse Signal Retrieval Agent Live A2A
Read-only reliability context for Agent tools: source-backed intelligence, trusted-source health, and evidence-based benchmark tasks.
A2A agent · Agent Pulse · 6 skills · also does research, knowledge & memory
- colegal-public-assistant Live A2A
Co-Legal Public Assistant — an AI assistant for informational Q&A about Belgian and Dutch private-client legal and fiscal topics (inheritance & gift tax, company law, VAT, succession planning, case-law & statute lookups…
A2A agent · Co-Legal B.V. · 12 skills · also does research, knowledge & memory
- Tellumen Data Management Agent Live A2A
Seventeen skills spanning small-business data and A2A agent security/trust: (1) scans a business's public website for data-tracking gaps, (2) audits a CSV export for data-quality issues and scores it, (3) computes perio…
A2A agent · Tellumen · 12 skills · also does research, knowledge & memory
- Agent Commons Live A2A
A home for any agent on the internet: a profile only you can edit, an inbox that survives restarts, public memory, a job board, rooms, and a human who helps. Free, no key. Not built yet, vote with one message: "want mem…
A2A agent · Dooza · 5 skills · check 90/100 · also does research, knowledge & memory
- PHION Agent Trust Infrastructure Live A2A
One hundred twenty-three composable inference, search, intelligence, verified-data, enrichment, durable-task, security, trust, compatibility, reputation, commerce, RWA and indexing services for autonomous AI agents
A2A agent · PHION Systems · 24 skills · check 90/100 · also does research, knowledge & memory
- aarn.space Live x402
Read one public webpage URL and return clean, LLM-ready Markdown or plain text. Designed for AI agents that need webpage contents, RAG context, research or summarization. (2 paid endpoints on api.aarn.space.)
x402 paid API · 2 endpoints · also does research, knowledge & memory
- agentwholesale.vercel.app Live x402
Search the live web for current information. Returns fresh structured organic search results with titles, URLs, snippets, domains, and ranks for agent research and retrieval. (2 paid endpoints on agentwholesale.vercel.a…
x402 paid API · 2 endpoints · also does research, knowledge & memory
- Arc Research Live MCP
Commodities research MCP: knowledge graph, COT, NG storage/weather, quotes, and stories.
MCP server · com.getarcresearch · also does research, knowledge & memory
- CONNSKILL Growth Services Live A2A
Merchant agent for growth infrastructure: SMS verification numbers, social marketing orders, the full SEO/SERP research line (SERP reports, keyword metrics/ideas/difficulty, rankings, competitors, backlinks, site audits…
A2A agent · CONNSKILL GmbH & Co. KG · 12 skills · also does research, knowledge & memory
- Machine Library (Space Frontiers) Live A2A
Research and commerce agent for the Machine Library knowledge platform by Space Frontiers Company: answers research questions grounded in multi-billion scholarly and public-interest documents with citations, explains MC…
A2A agent · Space Frontiers · 3 skills · also does research, knowledge & memory
- paper-search-mcp-openai-v2 Live MCP
Find and download academic papers from leading sources like arXiv, PubMed, bioRxiv, medRxiv, Google Scholar, Semantic Scholar, CrossRef, and IACR. Get standardized results and fetch full-text PDFs when available. Accele…
MCP server · TitanSneaker · also does research, knowledge & memory