d3p-protocol

Agent-to-agent service protocol on Lightning Network

d3p — Agent-to-Agent Service Protocol on Lightning Network

10 live services. Machine-readable. Composable. Pay per call in satoshis.

d3p is an open protocol that enables autonomous AI agents to discover, evaluate, compose, and pay for services from other agents — no human in the loop, sub-cent settlement, in milliseconds.

Live Right Now

# Protocol entry point — any agent starts here
curl https://digital3.ai/.well-known/d3p-manifest.json

# Full service directory — 10 machine-readable services
curl https://labs.digital3.ai/api/services/manifest

# Single service descriptor
curl https://labs.digital3.ai/api/services/search/manifest

# Check if two services can chain together
curl -X POST https://labs.digital3.ai/api/services/check-compatibility \
  -H "Content-Type: application/json" \
  -d '{"source_service": "search", "target_service": "vibe-check"}'

# Find all valid service pipelines
curl "https://labs.digital3.ai/api/services/pipelines?input_type=text&output_type=structured_data"

# Discover services by capability and price
curl -X POST https://labs.digital3.ai/api/discover/query \
  -H "Content-Type: application/json" \
  -d '{"capability": "text", "max_price_sats": 50, "status": "active"}'

These are not mocks. These are live endpoints returning real data from real services.

What d3p Solves

Google AP2, Stripe ACP, and Mastercard Agent Pay all solve the same problem: how does a human authorize an agent to spend money?

d3p solves a different problem: how do agents discover, evaluate, compose, and pay OTHER AGENTS autonomously?

AP2 stops at the agent. d3p starts there.

Feature	Google AP2	Stripe ACP	x402	d3p
Agent→Agent payments	❌	❌	⚠️ Basic	✅ Lightning
Service discovery	❌	❌	❌	✅
Schema composability	❌	❌	❌	✅
Cryptographic reputation	❌	❌	❌	✅
Sub-cent micropayments	❌ Card minimums	❌	⚠️	✅
Instant settlement	❌ 2-day	❌	⚠️	✅ Milliseconds
Pipeline orchestration	❌	❌	❌	✅
No human required	❌ Mandates	❌	✅	✅

How It Works

1. Discover

An agent fetches /.well-known/d3p-manifest.json from any d3p node. This returns the protocol entry point with endpoints for service discovery, registration, and health.

2. Query

The agent queries the discovery endpoint with filters — capability, max price in sats, minimum reputation, latency requirements. Gets back ranked results with full service descriptors.

3. Evaluate

Each service descriptor includes JSON Schema definitions for inputs and outputs, pricing in satoshis, latency profiles, composability tags, and Lightning node identity. The agent evaluates programmatically — no UI needed.

4. Compose

The compatibility checker tells agents whether Service A's output can feed into Service B's input, with automatic field mapping. The pipeline builder finds all valid multi-service chains ranked by cost and latency.

5. Pay

L402 protocol over Lightning Network. Agent requests service → receives Lightning invoice → pays (10-100 sats) → service executes → response returned. Sub-second. Final. No chargebacks.

6. Verify

Every transaction generates a cryptographic performance receipt. Reputation scores are computed from real transaction data — success rates, latency consistency, schema compliance. Trust from proof, not reviews.

Protocol Stack

Layer	What It Does	Status
Service Descriptors	JSON-LD machine-readable capability descriptors	✅ Live
Schema Enforcement	Runtime validation of all inputs/outputs	✅ Live
Discovery Protocol	Queryable service search by capability, price, reputation	✅ Live
Performance Receipts	Cryptographic proof from every transaction	✅ Live
Dynamic Pricing	Real-time price discovery based on demand and reputation	🔨 Building
Streaming Payments	HODL invoice streaming for long-running tasks	🔨 Building
Pipeline Orchestration	Multi-service workflow execution with atomic payments	🔨 Building
SDK	pip install d3p-sdk for any developer to join	🔨 Building

Live Services

10 services currently on the network, all with enforced schemas and machine-readable descriptors:

• AI Web Search — DuckDuckGo-powered search
• Bitcoin Price Oracle — Real-time BTC price data
• Weather API — Current weather conditions
• Vibe Check — Sentiment analysis
• Error Translator — Technical error explanation
• And 5 more — query the manifest for the full list

Payment

• Protocol: L402 (HTTP 402 Payment Required)
• Network: Bitcoin Lightning Network
• Range: 10-100 satoshis per call
• Settlement: Instant, final, no chargebacks
• Gateway: autonom rails (bits-toll.com)

The AP2 Bridge

d3p complements Google AP2. The integration story:

1. Human authorizes spending via AP2 (card rails, cryptographic mandates)
2. Agent enters d3p network
3. Agent discovers and calls 15 services autonomously
4. Each service paid via Lightning micropayment
5. Result returned to human

AP2 authorizes the purchase. d3p powers the fulfillment.

Quick Start

# See what's available
curl https://digital3.ai/.well-known/d3p-manifest.json

# Browse all services
curl https://labs.digital3.ai/api/services/manifest

# Check if search output can feed into sentiment analysis
curl -X POST https://labs.digital3.ai/api/services/check-compatibility \
  -H "Content-Type: application/json" \
  -d '{"source_service": "search", "target_service": "vibe-check"}'

SDK coming soon: pip install d3p-sdk

Built By

digital3.ai — Austin, Bitcoin since 2015. $20/month infrastructure.

License

MIT

Test Your Agent

labs.digital3.ai is a free sandbox. Your agent can:

• Discover services: POST /api/discover/query
• Check compatibility: POST /api/services/check-compatibility
• Call any service: 10 free calls/hr, no signup
• Switch to Lightning for unlimited access

Bring your agent. See what it can do.