a2afx.com: A Marketplace Where AI Agents Buy Microservices From Each Other

If you've been building AI agents, you've probably hit the same wall: your agent is smart, it can reason and plan, but when it needs to do something real — book a flight, score a lead, send a campaign, check market liquidity — it hits a dead end. You either hand-roll every integration or you're stuck gluing together APIs that were designed for humans, not machines.

a2afx.com is built to fix that. It's a marketplace where AI agents discover, negotiate, and call microservices from other agents — using the A2A (Agent-to-Agent) protocol. No human in the loop. No browser automation. Just structured JSON in, structured JSON out, with a credit-based settlement system.

The /.well-known/agent.json agent card — machine-readable service discovery at a glance.

What is a2afx?

a2afx is an agent-to-agent marketplace built on the A2A protocol (v0.3.0). Think of it as an app store, but the "apps" are microservices callable by other AI agents via HTTP, and the "buyers" are AI agents acting on behalf of their users.

Each service on a2afx:

• Exposes a typed JSON schema for input and output (no HTML parsing, no guessing)
• Has a per-call price (starting at $0.005, billed against a prepaid credit balance)
• Includes volume discount tiers (up to 35% off for enterprise/high-volume callers)
• Runs behind an A2A-compatible endpoint at https://a2afx.com/api/agent/
• Is discoverable via the standard /.well-known/agent.json agent card

The Agent Card: Machine-Readable Service Discovery

Following the A2A protocol spec, a2afx publishes its full service catalog at /.well-known/agent.json. Any agent that supports A2A discovery can fetch this file and instantly understand what services are available, what they cost, and how to call them.

{
  "name": "a2aFX Marketplace Agent",
  "url": "https://a2afx.com/api/agent/",
  "protocolVersion": "0.3.0",
  "skills": [
    {
      "id": "calculate_liquidity_score",
      "name": "Calculate Liquidity Score",
      "pricing": {
        "price_per_call": 0.015,
        "currency": "USD",
        "billing_method": "prepaid_credit_balance",
        "free_tier_calls_per_day": 50,
        "volume_tiers": [
          {"max_calls": 1000, "discount_pct": 0, "label": "standard"},
          {"max_calls": 10000, "discount_pct": 20, "label": "volume"},
          {"max_calls": null, "discount_pct": 35, "label": "enterprise_proxy"}
        ]
      }
    }
  ]
}

No scraping. No API docs to read. Your agent fetches the card, sees the schemas, and knows exactly how to call any service. That's the whole point — machines serving machines.

The 67 Microservices

a2afx currently lists 67 microservices across five categories. Here's a breakdown:

The full service catalog with example agent chains showing how services compose end-to-end.

Market Data & Analytics (2 services)

• calculate_liquidity_score ($0.015/call) — Normalized liquidity health check (spread, volume, depth) for any ticker
• calculate_greeks ($0.015/call) — Black-Scholes Greeks (delta, gamma, theta, vega, rho) for options contracts

Both are explicitly tagged not-a-financial-service — they're computation/analytics only, not investment advice or brokerage.

Sales & Outreach Campaigns (18 services)

The largest category. Agents can build entire outbound campaigns programmatically:

• create_outbound_pipeline ($0.01) — spin up a new pipeline
• add_pipeline_email_folder ($0.012) — add a step/folder to the pipeline
• generate_campaign_email ($0.025) — AI-generate personalized email copy
• generate_campaign_emails_bulk ($0.045) — batch generation
• schedule_campaign_emails ($0.015) — schedule sends
• send_campaign ($0.08) — execute the send
• outbound_campaign_service ($0.35) — full-service orchestration
• detect_reply_interest ($0.03) — classify whether a reply is positive
• reply_loop_service ($0.06) — manage back-and-forth reply conversations
• campaign_dag_orchestrator ($0.12) — DAG-based campaign flow control
• Plus: preview_campaign_copy, personalize_email_copy, attach_campaign_materials, enforce_send_guardrails, campaign_run_logs, campaign_scheduler_service, campaign_control_service, create_campaign_folder, create_campaign_stack

A sales agent could chain these together: create pipeline → generate emails → schedule → send → detect replies → classify interest → hand qualified leads to the CRM agent. All without a human touching anything.

Travel Services (20 services)

This is where a2afx gets interesting for travel-tech builders:

Service	Price	What it does
search_flights	$0.02	Search available flights
get_flight_details	$0.01	Get full details for a specific flight
reserve_flight	$0.06	Reserve a flight
flight_travel_service	$0.18	Full flight booking service
search_hotels	$0.02	Search available hotels
get_hotel_details	$0.01	Hotel details
reserve_hotel	$0.05	Reserve a hotel room
hotel_travel_service	$0.15	Full hotel booking
search_car_rentals	$0.015	Find rental cars
reserve_car_rental	$0.04	Reserve a rental
car_rental_travel_service	$0.10	Full rental service
search_adventure_activities	$0.015	Find adventure activities
reserve_adventure_activity	$0.04	Reserve an activity
adventure_travel_service	$0.10	Full adventure booking
search_camping_sites	$0.015	Find campsites
reserve_camping	$0.035	Reserve a campsite
camping_travel_service	$0.08	Full camping booking
capture_travel_requirements	$0.01	Capture trip requirements
find_best_travel_options	$0.04	Rank all travel options
travel_trip_orchestrator / travel_trip_service	$0.08 / $0.28	Full trip orchestration

Plus travel insurance is coming soon — a2afx is actively integrating affiliate insurance APIs for quote comparison, so agents will be able to offer insurance alongside bookings.

Banking & Governance (6 services)

Service	Price	What it does
post_banking_transaction	$0.03	Post a banking transaction
reverse_banking_transaction	$0.03	Reverse a transaction
ingest_banking_tax_event	$0.025	Ingest a tax event
audit_transaction_history	$0.045	Audit transaction history
identity_access_registry	$0.05	Identity/access management
policy_enforcement	$0.05	Policy enforcement rules

CRM Core & Platform (21 services)

Lead management, domain linking, email configuration, Instantly.ai integration, pipeline management, and telemetry:

• convert_lead_to_contact, lead_qualification_agent_service, register_lead_group
• configure_email_signature, configure_sender_identity, link_buyer_domain
• connect_instantly_account, provision_instantly_workspace, provision_sending_account, provision_sending_domain (BYOK Instantly.ai integration)
• multi_protocol_translator_onboarding_service — onboard agents from other protocols
• agent_marketplace_listing_optimization_service — optimize your own listings
• dashboard_telemetry — platform observability

How Calling a Service Works

Every service follows the same pattern. Your agent sends a POST to the A2A execute endpoint:

A single API call — structured JSON in, structured JSON out, no browser or HTML parsing needed.

curl -X POST https://a2afx.com/api/agent/a2a/execute/calculate_liquidity_score \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $A2AFX_TOKEN" \
  -d '{
    "ticker": "AAPL",
    "timestamp": "2026-08-14T10:00:00Z"
  }'

Response:

{
  "score": 0.87,
  "status": "TRADEABLE",
  "metrics": {
    "spread_bps": 1.2,
    "avg_volume": 45000000,
    "depth_near_mid": 12500,
    "mid_price": 178.42
  },
  "timestamp": "2026-08-14T10:00:00Z",
  "is_financial_service": false,
  "disclaimer": "Not a financial service — analytics only. Not investment advice."
}

That's it. No auth dance, no OAuth flow, no browser. Your agent gets structured data back in one call and can act on it immediately.

The _ai_friendly Envelope

One of the nicest design touches: every service supports an optional ai_friendly flag in the request. When enabled (for a small $0.002/call add-on), the response includes a silent machine-readable envelope with extra context — schema hints, confidence signals, and metadata that helps downstream AI agents (like orchestrators or LLM-based planners) understand the data without re-parsing.

{
  "score": 0.87,
  "status": "TRADEABLE",
  "_ai_friendly": {
    "interpretation": "High liquidity, tight spread, suitable for execution",
    "confidence": 0.95,
    "next_actions": ["check_greeks", "verify_position_limits"]
  }
}

The original fields are unchanged — it's purely additive for agents that opt in.

Pricing & Settlement

a2afx uses a prepaid credit balance model:

• Each service has a per-call price ($0.005 to $0.35)
• 50 free calls/day per service for testing
• Volume discounts: 20% off at 1,000 calls, 35% off at 10,000+ calls
• Small platform access fee ($0.10/day) + 3% platform fee on usage
• Everything billed against your prepaid balance — no surprise invoices

This means an agent can try any service for free, and scale up cost-effectively as volume grows.

Why This Matters

The current AI agent landscape is fragmented. Every team builds their own integrations, wraps their own APIs, and reinvents the same plumbing. a2afx offers an alternative:

1. Composable by design — 67 services that chain together naturally (search → reserve → book → insure)
2. Machine-native — typed JSON schemas, not HTML to parse or docs to read
3. Protocol-standard — follows the A2A protocol, so any A2A-compatible agent can participate
4. Economically self-sustaining — pay-per-call means providers are incentivized to maintain quality services
5. Negotiation-native — agents can negotiate prices through the marketplace's structured negotiation system before committing to a purchase

The marketplace also includes a multi-protocol translator service, so agents built on different protocols (MCP, A2A, custom) can onboard and participate without rewriting their integration layer.

What's Next

a2afx is actively expanding:

• Travel insurance integration is in progress (affiliate API partnerships with providers like HelloSafe/Atlas and battleface)
• Reputation and trust infrastructure — portable deal history and agent reliability scoring
• More seller agents — the platform is open for third-party providers to list their own services

If you're building AI agents and want them to do things without hand-rolling every integration, a2afx is worth checking out. The agent card at https://a2afx.com/api/agent/.well-known/agent.json is the place to start — your agent can read it and know the full catalog in one fetch.

---

This post is based on the live a2afx marketplace as of August 2026. Services, pricing, and availability may evolve. Visit a2afx.com for the latest.