What programming languages can I use?

Any language that makes HTTP requests. Ed25519 is supported natively in Node.js (crypto module), Python (PyNaCl), Go (crypto/ed25519), and Rust (ed25519-dalek).

Is there a rate limit?

Search: 100 req/min. Publisher endpoints: 10 req/min. Content updates: 30 req/min. Contact us for higher limits.

Can I manage multiple publishers?

Yes. Each publisher has its own domain, verification, and keypair. A single developer account can manage multiple publishers through the API.

What happens if the MCP server is down?

The REST API is always available as a fallback. MCP and REST share the same data layer.

Building on the ACN: Developer Guide

Architecture Overview

The ACN is designed as a three-layer stack that developers interact with at different levels depending on their use case:

Layer 1: Data Layer (MongoDB)

The canonical content_objects collection stores ~30 typed fields per business. Text indexes enable weighted search. Provenance chains track every content modification.

Layer 2: API Layer (REST + MCP)

REST endpoints at /api/acn/v1/ handle search, registration, verification, and content updates. The MCP server exposes five tools (query, get, facts, qa, verify) for AI platforms.

Layer 3: Intelligence Layer

Citation logging, quality scoring, and signal intelligence operate asynchronously. Every query generates attribution data. Every publisher registration triggers fraud detection.

Your First Integration

The fastest path to a working integration:

Step 1: Query the ACN

No authentication required for search. Send a GET request to /api/acn/v1/search?q=dentist&city=Miami and receive structured business data with provenance metadata.

Step 2: Build a Publisher Flow

If you are managing businesses, implement the three-step publisher flow: POST to register, DNS verification, then signed content updates. The API handles keypair generation and signal assessment.

Step 3: Connect via MCP

For AI agent integrations, connect your agent to the ACN MCP server. Five tools are exposed: query for search, get for retrieval, facts for citable statements, qa for Q&A pairs, and verify for provenance checks.

Start building

Read the complete API reference with endpoint specs, authentication, and example responses.

API Reference →

Content Signing with Ed25519

Content integrity is enforced through Ed25519 digital signatures. When a publisher verifies their domain, the system generates a keypair. The private key is returned once — it is never stored server-side.

Every content update requires:

Authorization header — Bearer token (API key issued at verification)
X-ACN-Signature — Ed25519 signature of SHA-256(body):timestamp
X-ACN-Timestamp — ISO 8601, must be within 5 minutes of server time

The 5-minute timestamp window prevents replay attacks. The SHA-256 hash ensures content integrity. The Ed25519 signature proves publisher identity. Together, these three mechanisms create a tamper-evident chain of custody for every piece of business data on the network.

Building on the Agent Content Network: The Developer Guide