x402

Prerequisites

MetaNet Client must be running. Check with:

curl -s -H "Origin: http://localhost" http://localhost:3321/isAuthenticated

If not running, tell the user to start it (macOS: /Applications/Metanet Client.app, or download from https://getmetanet.com).

Task

$ARGUMENTS

Agent Registry

A directory of available agents lives at x402agency.com. Run list to see all registered agents — their names, capabilities, and URLs. Agent names resolve automatically anywhere a URL is expected.

Always start with list when the user's request could match any registered agent. Use the agent descriptions, capabilities, and taglines to match the user's natural language intent to the right agent. Don't assume which agent to use — check the registry.

The registry is cached locally for 5 minutes at ~/.local/share/brc31-sessions/registry.json. Full URLs (https://...) still work directly and bypass the registry.

Commands

All operations use the helper script bundled with this skill. All commands output JSON to stdout.

Command	Purpose
python3 ./scripts/brc31_helpers.py list	List all agents from the x402agency.com registry
python3 ./scripts/brc31_helpers.py discover <name_or_url>	Learn server endpoints, auth requirements, costs
python3 ./scripts/brc31_helpers.py auth <METHOD> <name_or_url> [body]	Authenticated request (no payment)
python3 ./scripts/brc31_helpers.py pay <METHOD> <name_or_url> [body]	Authenticated + paid request (auto-handles 402)
python3 ./scripts/brc31_helpers.py identity	Get wallet's 66-char hex identity key
python3 ./scripts/brc31_helpers.py execute-action <json>	Execute a pending action template (broadcasts inscription tx after user confirms)
python3 ./scripts/brc31_helpers.py session <base_url>	Inspect cached session

Handshake is automatic — never call it manually before auth or pay.

Decision Tree

1. List — Run list to see all registered agents. Match the user's intent to an agent by reading the name, tagline, and capabilities from the registry. There may be many agents — pick the best match.

2. Discover — Run discover <agent_name> on the matched agent to get its full manifest: endpoints, pricing, input schemas. Present a summary to yourself (or the user if they're exploring).

3. Route — Match user intent to an endpoint:

   • auth: true, no payment → use auth
   • payment with satoshis → use pay (do NOT ask user to confirm — consent is implicit by invoking this skill; typical costs are 1-100 sats)
   • auth: false → plain curl, no skill needed

4. Call — Run the appropriate command. For requests with a JSON body, pass it as the 4th argument:

   python3 ./scripts/brc31_helpers.py pay POST <agent_name>/<endpoint> '{"key":"value"}'
   

5. Present — Parse the JSON response ({status, headers, body}). The body is a string that may contain nested JSON — parse it before presenting.

6. Action — If the pay response contains pending_action (e.g. from 1sat-agent), present the cost breakdown to the user and ask for confirmation before calling execute-action. Do NOT broadcast automatically. The pending_action includes costs (service fee, estimated mining fee, estimated total) and the action template. Once the user confirms, run:

   python3 ./scripts/brc31_helpers.py execute-action '<action_json>'
   

   The result includes txid and inscription_id.

Examples

Typical flow: user asks for something an agent can do

User asks: "generate an image of a sunset"

# Step 1: Check what agents are available
python3 ./scripts/brc31_helpers.py list
# → Returns JSON array. Read taglines/capabilities. Pick the image generation agent.

# Step 2: Discover its endpoints and pricing
python3 ./scripts/brc31_helpers.py discover <matched_agent_name>
# → Returns manifest with endpoints, pricing tiers, input schemas

# Step 3: Call the paid endpoint
python3 ./scripts/brc31_helpers.py pay POST <agent_name>/<endpoint> '{"prompt":"a sunset"}'
# → Handles auth + 402 + payment automatically. Returns result.

Discovery by URL (for unregistered servers)

python3 ./scripts/brc31_helpers.py discover "https://some-server.example.com"

Returns a manifest with name, serverIdentityKey, endpoints[].

Authenticated request (free endpoint)

python3 ./scripts/brc31_helpers.py auth POST <agent_name>/<endpoint>

Direct URL (bypasses registry)

python3 ./scripts/brc31_helpers.py pay POST "https://some-server.example.com/paid"

Refunds

Servers that support BRC-29 refunds will automatically return refund data when a paid request fails after payment. The client auto-detects and internalizes refunds — no manual action needed.

• Inline refunds: Returned in the same response as the error (e.g., /paid fails immediately)
• Deferred refunds: Returned later when polling /status/{id} for async operations that failed

The discover command shows which endpoints support refunds. The pay command output includes a refund block when a refund was received and internalized.

Payment Transport

Payment is sent via x-bsv-payment header as JSON: {"derivationPrefix":"...","derivationSuffix":"...","transaction":"<base64 BEEF>"}. The client handles this automatically.

Header-only servers: Most servers only accept payment in the header. The client has a body-mode fallback for payments >6KB, but only uses it when the request has no original body to preserve. Typical payments are ~2KB, well under the threshold.

Default Test Server

• Live: https://poc-server.dev-a3e.workers.dev
• Local: http://localhost:8787 (run cd poc-server && npm run dev)

When NOT to Use

• Regular HTTP APIs without BSV authentication
• APIs using OAuth, API keys, or JWT (unless specifically BRC-31)
• Coinbase x402 protocol (EVM/Solana only — this skill is BSV-only)

Troubleshooting

Only consult this section if something goes wrong.

Symptom	Fix
MetaNet Client not running	Start MetaNet Client app or download from https://getmetanet.com
Discovery returns 404	Server may not have /.well-known/x402-info; proceed with known endpoint info or ask user
Connection error	Server may be down or wallet not running
Payment error	Tell user to check MetaNet Client for approval prompt; may also be insufficient funds
Signature is not valid on POST	Session may be stale. Clear: python3 ./cli.py session --clear <server_url>
Persistent auth failures	Clear session: python3 ./cli.py session --clear <server_url>
Need verbose output	Use full CLI: python3 ./cli.py -v auth POST "<url>"