ln-church-agent

The Value of "Not a Verdict" LN Church read models do not decide for the agent. They preserve observed memory: what was seen, what was paid, what failed, what receipt shape appeared, what protocol role was observed, and what verification cost was reported. This is not a recommendation or verdict; it is a reusable observation record that helps the local runtime avoid re-verifying everything. Final payment authority remains local.

Your agent will hit a 402 paywall in the wild.

Will it inspect, decide, pay, recover, verify, and continue — or freeze?

ln-church-agent is a buyer-side HTTP 402 runtime and agent-commerce surface inspector for autonomous agents.

In the broader agentic commerce stack, ln-church-agent acts as the buyer-side component of an observability and trust-evidence layer for HTTP 402-compatible paid actions.

It helps agents inspect paid-action surfaces, distinguish executable payment rails from higher-order commerce protocols, and prove paid execution across L402, x402, and supported MPP charge shapes when a concrete HTTP 402-compatible challenge, supported credential path, and verifiable receipt path are present

In v1.9.0+, the inspect layer explicitly classifies emerging agent-commerce surfaces such as OKX Agent Payments Protocol (APP), Google AP2, and ACP without executing payment logic. These protocols are treated as observable commerce / authorization patterns unless they expose a concrete HTTP 402-compatible settlement path.

Core Doctrine

Do not spend even one LLM token on what the agent should not need to reason about.

ln-church-agent moves payment plumbing out of the model's reasoning loop and into a deterministic buyer-side runtime.

The SDK handles mechanical HTTP 402 concerns such as:

• payment-rail inspection,
• challenge parsing,
• policy checks,
• payment execution,
• HATEOAS recovery,
• receipt verification,
• evidence capture.

The LLM remains responsible for the higher-level economic decisions:

• whether the counterparty should be trusted,
• whether payment is justified,
• whether the expected outcome was delivered,
• and whether the endpoint should be reused.

Don't Trust, Verify. But Don't Re-Verify Everything.

The SDK is designed for verification reuse: agents can inspect and verify live payment flows when necessary, but they should reuse observed memory, receipts, and read models when repeated full verification would waste context, liquidity, or reasoning budget.

What it does

Most payment SDKs help agents pay.
ln-church-agent helps agents complete the whole paid-action loop:

Probe → Inspect → Decide → Pay → Execute → Verify → Trace

It is designed for agents that must:

• Inspect HTTP 402 challenges before committing funds.
• Choose between L402, x402, MPP, or safe-stop paths based on local policy.
• Execute paid actions through policy-aware runtime controls (budgets, trust).
• Recover through HATEOAS-style next actions if a flow is interrupted.
• Verify receipts and semantic outcomes after payment.
• Report trace evidence to a public sandbox or local observer.
• Record goal-conditioned attempts and their outcomes for future optimization.

🧠 What this runtime is

• Generic Buyer-Side Runtime: A pure client-side execution engine that keeps your AI agent's reasoning loop clean by abstracting away the HTTP 402 negotiation layer.
• Agent Commerce Surface Inspector: Classifies emerging commerce and authorization layers such as OKX APP, AP2, ACP, and UCP separately from executable settlement rails.
• Open-Web 402 Interoperability: Natively supports Base64URL JSON headers, CAIP-2 network routing, and multi-chain execution out of the box.
• Reference Sandbox Support: Optionally integrates with the LN Church observation network for public benchmarking, trace reporting, and discovery workflows.
• Stable Interface: An unchanging developer API surface that safely absorbs the constant fluctuations of upstream protocol drafts.

Two Runtime Modes

To provide safe boundaries for enterprise AI orchestration, ln-church-agent explicitly separates surface inspection from payment execution.

Explicit MCP Routes and Telemetry Boundaries

ln-church-agent provides two distinct Model Context Protocol (MCP) entrypoints:

• 1. Inspect-only MCP (ln-church-agent-mcp): Use ln-church-agent-mcp for enterprise/read-only/preflight inspection. It never signs, pays, or executes transactions. Telemetry Side-effects: This MCP never auto-submits telemetry. It may submit redacted observation telemetry only when the submit_mcp_observation tool is explicitly invoked by the agent.

• 2. Execution-capable MCP (python -m ln_church_agent.integrations.mcp): Use python -m ln_church_agent.integrations.mcp only when the operator explicitly wants an MCP server that can execute paid actions with configured credentials (e.g., Lightning wallets or EVM signers).

Paid Surface Observer

ln-church-agent is not only a payment executor but also a powerful paid surface observer. The inspect command enumerates all presented settlement_options alongside the selected_settlement_option (the one the SDK would choose if executing). It cleanly separates capabilities: what can be observed versus what is natively supported for execution (execution_support).

Agent Commerce surfaces like APP, AP2, and ACP are treated strictly as commerce/authorization layers. They are processed as inspect-only, meaning the SDK will intentionally avoid automatic execution and explicitly highlight missing settlement parameters (missing_information) if clear rails are undeclared.

LN Church Observatory Opt-in: ln-church-agent can inspect payment surfaces locally. LN Church Observatory is the public observation layer where redacted observations, execution evidence, and interoperability traces can be collected and compared across HTTP 402 / x402 / L402 / MPP surfaces.

The SDK never submits observations automatically. Publishing observations to LN Church must be explicit and opt-in.

Verifiable Reporter Identity Layer (v1.12.0+)

As of v1.12.0, the SDK supports an optional, client-managed Verifiable Reporter Identity Layer via ensure_reporter_verification().

• Key Control vs Report Truth: This layer proves only that the reporting agent controls the private key associated with its agentId. It does not verify the semantic correctness or truth of the submitted telemetry.
• Strictly Non-Mandatory: Verification is completely optional. Telemetry submission fundamentally preserves its privacy-first, opt-in posture.
• No Trust Scores: key_control_verified is not a trust score, certification, recommendation, or settlement proof.
• self_reported Remains First-Class: Runtimes must function identically for self_reported (unverified) agents. Unverified simply means the key-control loop was not explicitly executed.
• No Auto-Hooks: ensure_reporter_verification() is never automatically triggered inside execution methods like execute_detailed() or submit_goal_attempt_observation(), ensuring deterministic management of token overhead.
• Safety Note: agentId can be a 64-character hex identifier, but it is treated strictly as a public identifier. Never submit private keys as your agentId. For EVM public key verification, the agentId must explicitly be the 40-character 0x-prefixed public address.

Managed Platform Boundary

ln-church-agent is not a managed wallet, payment processor, or cloud payment orchestration service.

Managed platforms such as AWS AgentCore Payments help agents execute payments inside a hosted wallet/session environment. ln-church-agent focuses on the open-web buyer side: inspecting HTTP 402 and agent-commerce surfaces, distinguishing executable settlement rails from commerce / authorization layers, enforcing local policy, verifying outcomes, and capturing evidence across protocols.

Use managed platforms when you need hosted wallet custody, cloud-side payment sessions, and provider-managed payment execution.

Use ln-church-agent when you need lightweight, local, cross-protocol inspection, decision support, evidence capture, sandbox validation, or non-AWS / open-web interoperability.

Submitting Observations Safely

Do not use the low-level execute_request() method to manually POST payloads to the /api/agent/external/observe endpoint, as this bypasses schema normalization and may trigger strict internal HATEOAS/Cross-Origin guardrails.

• Standard Observations: Use submit_external_observation().
• Unmapped/Unknown Surfaces: Use submit_unmapped_observation().

from ln_church_agent import LnChurchClient

client = LnChurchClient()

client.submit_unmapped_observation(
    target_url="https://example.com/api/endpoint",
    detection_note="payment_scheme_unmapped",
    rails_detected=["Payment"],
    status_code=402,
)

Note: Unmapped observations are treated strictly as discovery signals. They declare payment_performed=False and verification_status="unverified". Default telemetry auto-submission scripts remain conservative; explicit opt-in is required to submit unmapped observations.

Where it fits

• ln-church-agent: Buyer-side runtime for agents facing HTTP 402 challenges.
• ln-church-server: Provider-side starter for building agent-facing paid APIs.
• LN Church Sandbox: Public proving ground for benchmark, receipt, trace, and interop evidence.
• Evidence Tracking (v1.8.4+): ln-church-agent can now capture sponsored-access and sandbox execution metadata as local evidence (SponsoredAccessEvidence / SandboxEvidence). Sandbox evidence is strictly scoped to LN Church's controlled sandbox environment (evidence_scope: "sandbox_internal") and intentionally does not auto-submit external observations. Raw secrets are securely redacted.
• Corpus Readiness (v1.8.5+): SandboxEvidence can be converted into a local SandboxCorpusCandidate. This does not submit to ExternalObserve. Final corpus acceptance remains server-side.
• Goal Attempt Memory (v1.10.0+): Captures free, paid, and mixed steps toward a declared goal, serving as a foundational data lake for agentic behavior before recipes are applied.

Relationship to official protocol SDKs

ln-church-agent is a complement, not a replacement, for official protocol SDKs.

• Use official protocol SDKs for simple, pure protocol-native settlement.
• Use ln-church-agent when the agent needs deterministic inspection, policy-aware decision support, HATEOAS recovery, receipt verification, evidence capture, cross-protocol comparison, or traceable paid-action attempts.
• Final payment authority remains local. The network can advise, but the SDK's local PaymentPolicy explicitly supersedes remote advice.

🧠 AI Decision Card

Use ln-church-agent when an AI agent must do more than simply pay for one API call.

Choose this SDK when the agent needs:

• Multi-rail support: L402, x402, and MPP-aware flows.
• Policy enforcement: Local spend limits, session budgets, and trust checks.
• Verifiable evidence: Receipts, evidence records, and traces for auditing.
• Safe stopping: Graceful handling of unsupported or unstable payment sessions.
• Commerce surface inspection: Detect OKX APP-style agent-commerce metadata while keeping execution disabled unless a supported 402 rail is present.
• Goal-conditioned attempt tracking: Explicitly record multi-step attempts (free, paid, mixed) and their optional outcomes.

Use a lightweight 402 proxy when the task is only a one-off, low-risk pay-and-fetch.

⚡ First Success: Inspect Before Paying

Start with a no-payment inspection command. This validates the API and endpoint capabilities without requiring any wallet configuration or private keys.

pip install ln-church-agent
ln-church-agent inspect https://kari.mayim-mayim.com/api/agent/sandbox/mpp/charge/basic --json

This command does not execute payment. It detects the HTTP 402 challenge, identifies the payment rail, recommends a safe action, and prints the next command.

Canonical first loop: inspect → decide → pay → verify → trace

• For exact capability and execution boundaries, see the Capability Matrix.
• For future standards tracking and deferred items, see Standards Watch Alignment.

🧭 Agent Commerce Surface Inspection

ln-church-agent v1.8+ extends inspect from a payment-rail preflight tool into an Agent Commerce Surface Inspector, with v1.9.0 adding explicit classification for Google AP2 and ACP.

It can safely detect higher-order commerce metadata, starting with OKX Agent Payments Protocol (APP), AP2 mandates, and ACP checkouts, while keeping settlement execution strictly disabled during inspection.

In v1.9.1+, inspect results can also include Guided Handoff metadata for AP2 / ACP / OKX APP-like surfaces. This tells the upstream agent what to ask the site for, what not to treat as settlement proof, which evidence is required, what information is missing, and why operator approval may be required.

Grant-like Signal Detection Sidecar (v1.12+): The inspect tool may also detect unverified incentive signals (e.g., faucets, trial credits) as a local sidecar observation.

• This is not a guarantee of grant availability.
• It does not verify signed grant tokens or redeemability.
• It is not automatically submitted to the Hon-den observation network.
• The SDK maintains strict not_a_recommendation, not_a_verdict, and unassessed_is_not_failed principles.

Example output:

{
  "ok": true,
  "url": "https://api.example.com/checkout",
  "http_status": 402,
  "surfaces_detected": ["ACP"],
  "settlement_rails_detected": ["x402"],
  "surface_type": "checkout",
  "commerce_protocol": "acp",
  "commerce_intent": "agentic_checkout",
  "settlement_rail": "x402",
  "recommended_action": "observe_only",
  "will_execute_payment": false
}

{
  "handoff_mode": "guided_handoff",
  "approval_required": true,
  "ask_site_for": ["quote_details", "settlement_rail_options", "receipt_or_proof_model"],
  "do_not": ["treat_authorization_artifact_as_settlement_proof"],
  "required_evidence": ["explicit_price", "merchant_identity", "settlement_rail", "receipt_model"]
}

This distinction is intentional:

• L402 / x402 / MPP are treated as executable payment rails.
• Google AP2 / ACP / OKX APP / card-network agent payments are treated as commerce, authorization, identity, or checkout surfaces. Even if they expose a concrete HTTP 402-compatible settlement path, their baseline recommendation defaults to observation.
• inspect never executes payment, initializes wallets, signs payloads, or calls brokers.

Use this mode when your agent needs to understand a paid-action surface before deciding whether payment execution is safe, unsupported, or observation-only.

🔭 Paid Domain Observation Slot (v1.14.0+)

ln-church-agent allows agents or human operators to explicitly register a public domain for an extended 7-day observation run by the LN Church observatory queue via an HTTP 402 paid action.

Strict Architectural & Safety Rules:

• Paid Domain Observation Slot is a paid request to LN Church, not a payment to the target domain.
• It is not a security scan, endorsement, certification, recommendation, or trust score.
• MVP v0 does not verify domain ownership. (requester_paid=true, domain_owner_verified=false). Requester paid and domain owner verified are entirely separate concepts.
• Internal workers fetching targets from this queue operate under strict public-safe constraints (GET/HEAD only, no forms, no login, no vulnerability scan, no payment to target).
• Results are published to public-safe read models.

CLI Usage:

# Register a domain for observation (approx 1 USDC via x402)
ln-church-agent observe-domain register example.com --pay

# Check the active queue status (free, read-only)
ln-church-agent observe-domain status obsreq_xxxxx

# Read the public-safe observation facts (Read Model)
ln-church-agent observe-domain read-model example.com

SDK Usage:

from ln_church_agent import LnChurchClient

client = LnChurchClient(private_key="0x...")

# 1. Paid Registration (Requires funds)
res = client.register_domain_observation_slot("example.com")
print(f"Request ID: {res.request_id}")

# 2. Check Status (Free, Read-Only)
# Can be called safely without private keys: LnChurchClient(agent_id="cli_observer")
status_client = LnChurchClient(agent_id="cli_observer")
status = status_client.get_domain_observation_request(res.request_id)

# 3. Fetch Domain Read Model (Free, Read-Only)
read_model = status_client.get_domain_observation_read_model("example.com")

🛡️ Verified Domain Sponsor (v1.15.0+)

For Paid Domain Observation Slots, ln-church-agent v1.15.0+ allows the sponsor to cryptographically prove they control the target domain's public web surface by placing a deterministic challenge document at a .well-known path.

Strict Architectural & Safety Rules:

• Domain Control Only: This proves the sponsor could publish a file on the domain. It explicitly is NOT a legal ownership proof.
• Not a Verdict: Verified domains are not ranked higher, trusted inherently, or endorsed by LN Church (not_a_verdict: true, not_an_endorsement: true).
• No Automatic Execution: The SDK intentionally does not automatically issue challenges or verify sponsors after registration to prevent unprompted executions.
• Secret Leakage Prevention: The CLI and SDK strictly redact proof headers (X-LN-Result-Handle, X-LN-Request-Hash) and the challenge_token from standard outputs.

CLI Usage:

# 1. Issue a challenge and save the document locally safely
ln-church-agent observe-domain sponsor challenge obsreq_xxxxx \
  --output-file ".well-known/ln-church-domain-sponsor.json"

# 2. (Manual Step) Publish the JSON file to exactly:
# https://{target-domain}/.well-known/ln-church-domain-sponsor.json

# 3. Request the LN Church backend to fetch and verify the document
ln-church-agent observe-domain sponsor verify obsreq_xxxxx

SDK Usage:

from ln_church_agent import LnChurchClient

client = LnChurchClient(agent_id="domain_sponsor_cli")

# 1. Issue Challenge
challenge = client.create_domain_sponsor_challenge(
    request_id="obsreq_xxxxx",
    result_handle="pr_...", 
    request_hash="sha256:..."
)

# 2. Save Document Safely (excluding headers/secrets from the file)
client.save_domain_sponsor_challenge_document(
    challenge, 
    ".well-known/ln-church-domain-sponsor.json"
)

# 3. Verify
verified = client.verify_domain_sponsor(
    request_id="obsreq_xxxxx",
    result_handle="pr_...", 
    request_hash="sha256:..."
)

print(f"Domain Control Verified: {verified.domain_control_verified}")
print(f"Legal Ownership Proof: {not verified.not_legal_ownership_proof}") # Evaluates to False

MCP: Inspect-only payment surface discovery

ln-church-agent-mcp is the inspect-only MCP entrypoint bundled with ln-church-agent.

It is intended for MCP-compatible agents that need to discover and inspect HTTP 402 / agent-commerce surfaces before deciding whether any separate payment execution engine should be used.

v1.9.2 adds ln-church-agent-mcp, a keyless MCP server for AI orchestration frameworks that need to inspect paid surfaces without executing payment.

It exposes inspect / explain / observation-payload tools, returns Guided Handoff metadata when available, and hard-locks payment_performed=false.

ln-church-agent-mcp is a public, inspect-only MCP server designed for safe reconnaissance. It parses HTTP 402 paid surfaces, returning detailed structural classifications for L402, x402, MPP, OKX APP, AP2, and ACP.

• No Payments Executed: It strictly analyzes the response and suggests a recommended_action.
• No Private Keys Required: It operates entirely without wallet adapters or identity credentials.
• Safe Telemetry: The server can build and submit observations to /api/agent/external/mcp-observe with guaranteed secret redaction. (It does not auto-submit).

Remote MCP scope note:
v1.9.2 provides a bundled stdio MCP server for inspect-only payment surface discovery.
Remote MCP / Claude custom connector hosting is not included in this release and is planned as future scope.

To expose these safe tools to your AI agent:

ln-church-agent-mcp

Payment Failure Observation

v1.9.4 introduces a structured layer for recording and analyzing 402 payment attempt failures. Rather than viewing failures as binary "broken" states, this layer treats them as Observations—structured evidence of friction encountered under specific conditions (e.g., dynamic feePayer fields causing retry mismatches).

• Structured Knowledge: Converts execution crashes into reusable PaymentFailureRecord artifacts.
• Privacy by Design: Automatically fingerprints and redacts raw secrets (preimages, private keys, macaroons) from challenge dicts and error messages.
• Interoperability Analysis: Detects when server-side requirements drift between initial inspection and payment retry.

Code Example

from ln_church_agent.failures import build_payment_failure_record, build_payment_failure_observation_payload

# 1. Build a local record of the failure
record = build_payment_failure_record(
    endpoint="https://api.example.com/data",
    rail="x402",
    scheme="exact",
    failure_subclass="no_matching_payment_requirements",
    server_message="Your macaroon is invalid", # 'macaroon' will be [REDACTED]
    challenge_before={"accepts": [{"feePayer": "NodeA"}]},
    challenge_after={"accepts": [{"feePayer": "NodeB"}]},
    secondary_client_used="x402-official-client"
)

print(record.changed_fields) 
# Output: ['accepts[0].feePayer']

# 2. Build a public-safe payload for future ingestion
payload = build_payment_failure_observation_payload(record, agent_id="agent-007")
print(payload["evidence"]["payment_performed"]) 
# Output: False

Note: The SDK currently builds these records locally. Automatic submission to the LN Church failure registry is disabled in this release pending server-side support.

Surface Preflight Read Model (v1.11.0+)

Before touching a specific paid surface, your agent can explicitly read the Hon-den's observed historical memory for that endpoint to inspect past friction, evidence grades, and settlement options.

• This is NOT a recommendation. A reusable observation record.
• This is NOT a verdict. A reusable observation record.
• This is NOT a payment proof.
• It does NOT execute payments.
• Final decision authority remains with your local runtime (PaymentPolicy / TrustEvaluator).
• Unknown surfaces are NOT "unsafe"—they simply mean they haven't been observed by the registry yet.

from ln_church_agent import LnChurchClient

client = LnChurchClient(base_url="https://kari.mayim-mayim.com")

# Query deterministically by URL and protocol shapes
card = client.get_surface_preflight(
    target_url="https://api.example.com/protected",
    method="GET",
    rail="x402",
    network="eip155:8453",
    asset="USDC",
    authorization_scheme="x402",
    draft_shape="exact",
)

print(card["schema_version"])
print(card["surface"]["known"])
print(card["not_a_recommendation"])
print(card["guardrails"]["final_authority"])

# Or query directly by Surface Key if known
card2 = client.get_surface_preflight(surface_key="surface_0123456789abcdef01234567")

Goal Attempt Observation (v1.10.0)

ln-church-agent can now explicitly submit Day 1 Goal Attempt observations.

A Goal Attempt records what an agent tried to accomplish for a declared goal, which surfaces it used, whether those steps were free, paid, mixed, observe-only, or simulated, and optionally whether the attempt satisfied the goal.

This is not automatic telemetry.

It does not:

• execute a payment,
• recommend a recipe,
• auto-submit from execute_detailed(),
• change L402/x402/MPP execution behavior.

If outcome is omitted, the attempt is recorded as unassessed. This is intentional: unassessed attempts may still become useful when the Goal Attempt Graph is reinterpreted with newer goal taxonomies and outcome rubrics.

client.submit_goal_attempt_observation(
    goal={
        "goal_text": "Explain this Solana transaction and identify missing confidence signals",
        "declared_goal_type": "tx_investigation",
        "domain_hint": "crypto"
    },
    attempt={
        "attempt_mode": "free",
        "completion_status": "partial_success",
        "total_monetary_cost": 0,
        "total_reasoning_cost_estimate": "medium"
    },
    steps=[
        {
            "step_index": 1,
            "step_role": "fetch",
            "surface_key": "web:solscan:tx_page",
            "surface_type": "web_page",
            "payment_performed": False,
            "status": "success",
            "output_semantic_type": "tx_summary"
        }
    ],
    evidence={
        "evidence_class": "agent_report",
        "verification_status": "self_reported",
        "payment_performed": False
    }
)

🧭 Goal Attempt Memory Read Models (v1.10.0)

While full behavioral mapping is achieved via the premium graph, analyzing the complete monzen-graph.json during an active reasoning loop can cause context-window bloat. ln-church-agent v1.10.0 introduces two lightweight, static S3 snapshot endpoints to read historical attempt context efficiently.

Rational Read Order for Autonomous Agents

To minimize data ingestion and allocation overhead, autonomous agents SHOULD query information using the following hierarchy:

1. Goal Attempt Summary (Free): Query overall volume counters and unassessed ratios to determine base-layer viability.
2. Goal Surface Candidates (Paid - 1 SAT): Fetch up to 20 historically observed surfaces previously harnessed by the network for a specific objective.
3. Full Resonance Graph (Premium - 10 SATS): Download the full multi-chain dataset only when deep analytical structural mapping is required.

Code Example: Fetching Summary and Candidates

from ln_church_agent import LnChurchClient, AssetType

client = LnChurchClient(private_key="0x...")

# 1. Fetch Lightweight Summary (Completely Free)
summary = client.get_goal_attempt_summary(
    goal_type="tx_investigation",
    domain_hint="crypto"
)
print(f"Total Attempts Recorded: {summary['goals'][0]['attempt_count']}")

# 2. Fetch Observed Candidate Surfaces (Paid: 1 SAT / 0.001 USDC / 1 JPYC)
# Warning: If unpaid, this triggers a standard HTTP 402 challenge loop.
candidates = client.get_goal_surface_candidates(
    goal_type="tx_investigation",
    domain_hint="crypto",
    prefer_free_first=True,
    asset=AssetType.SATS,
    scheme="L402"
)

# Candidates are observed records, NOT recommendations or verdicts
for surface in candidates["candidate_groups"][0]["candidate_surfaces"]:
    print(f"Observed Surface: {surface['surface_key']} (Used: {surface['used_count']} times)")

Strict Architectural Guardrails:

• Not a Recommendation. A reusable observation record: Candidate surfaces are historical memory markers, not recipe predictions or active verdicts (not_a_recommendation: true).
• Unassessed Integrity: Traces with missing outcomes indicate an unassessed state, never an execution error.
• Fixed Cost Isolation: Candidate lookups utilize an isolated pricing table, completely decoupled from full graph pricing.

⚡ Start in 5 Minutes

Choose your execution path based on your immediate goal:

Route A: Generic Paid Fetch (Open Web Integration)

Integrate with any HTTP 402 compliant API on the open web. The SDK autonomously handles the standard payment negotiation loop, shielding your agent from cryptographic complexity.

from ln_church_agent import Payment402Client

client = Payment402Client(base_url="https://your-402-api.com", private_key="0x...")

# Inspects 402 -> Applies policy -> Pays if allowed -> Retries -> Verifies response
result = client.execute_request(
    method="POST",
    endpoint_path="/api/protected",
    payload={"input": "data"}
)
print(result)

Route B: Agent Tool Integration (MCP)

Instantly equip any Model Context Protocol (MCP) compatible agent (e.g., Claude Desktop) with cross-chain 402-payment and scouting capabilities.

export AGENT_PRIVATE_KEY="your-0x-prefixed-key"
python -m ln_church_agent.integrations.mcp

Your agent can now autonomously call paid tools and benchmark flows directly from its reasoning loop.

Route C: Public Benchmark against LN Church Sandbox

Prove your agent's parsing and execution capabilities against the physically isolated Agentic Payment Sandbox. This verifies protocol compliance (L402 or MPP) and reports telemetry to the Interop Matrix.

from ln_church_agent import LnChurchClient

client = LnChurchClient(private_key="0x...")

# Autonomously validate standard L402 compliance
l402_result = client.run_l402_sandbox_harness()

# Or, validate the new Machine Payments Protocol (MPP) charge flow
mpp_result = client.run_mpp_charge_sandbox_harness()

print(f"L402 Hash Matched: {l402_result.canonical_hash_matched}")
print(f"MPP Hash Matched: {mpp_result.canonical_hash_matched}")

Observation → Corpus → Synthetic Replay → Agent Dry-run Validation

ln-church-agent v1.8+ closes the agent-side of the LN Church interop loop.

It can read server-side synthetic_from_corpus_v1 replay descriptors and validate whether the local parser and decision engine choose the expected behavior:

• pay_and_verify
• observe_only
• stop_safely
• reject_invalid

This is a dry-run validation path. It does not execute real payments and does not attempt raw wire-level replay.

from ln_church_agent import LnChurchClient

client = LnChurchClient(private_key="0x...")

# Dry-run a synthetic replay descriptor from the Corpus
replay_result = client.run_corpus_replay(
    corpus_id="corp_12345",
    dry_run=True
)

print(f"Success: {replay_result.ok}")
print(f"Expected: {replay_result.expected_action}, Observed: {replay_result.observed_action}")

🛡️ Why teams adopt this runtime

• Avoid tracking protocol churn: Developers should not need to track every upstream revision manually. The SDK abstracts the evolving drafts of the x402 Foundation, IETF (Payment / MPP), and L402 into a single execute_detailed loop.
• Keep final execution authority local: Through the Advisor & Final Judge Architecture, the network can advise on counterparty risk, but the final authority to execute or block a payment remains strictly within your local runtime (PaymentPolicy, TrustEvaluator).
• Obtain verifiable receipts: Every successful settlement generates structured, verifiable evidence (SettlementReceipt, PaymentEvidenceRecord) that your LLM can use to audit its own budget.
• Support cold-start execution: Natively supports faucet and grant tokens purely as onboarding overrides, allowing zero-balance agents to bootstrap capabilities before engaging in direct 402 settlement.
• Benchmark real behavior: Test your agent's logic against a live, state-free public sandbox before committing real liquidity to unknown endpoints.

🔌 Protocol Coverage

The SDK supports multiple settlement rails through a unified interface.

Standard x402 v2 (Global Standards):

• EVM exact (x402): Standard EVM-based settlement utilizing strict EIP-712/EIP-3009 gasless authorization payloads.

• SVM exact (Solana): Official x402 v2 SVM exact payments via CAIP-2 solana:<genesisHash> networks. This SDK features a built-in transaction builder for standard x402 SVM exact compatible payloads.

• Note: The current LN Church exact sandboxes act as post-settlement validators. They require submitted tx hash / signature evidence and will reject unbroadcasted payloads. True V2 exact settlement (facilitator broadcasting) is a future phase.

• L402 / MPP: Standard Lightning Network settlement (SATS) supporting Macaroon and BOLT11 invoice parsing.

Compatibility & Sandbox Paths (LN Church Extensions):

• lnc-solana-transfer: Legacy compatibility path for direct SPL Token (USDC) transfers via Solana RPC.
• lnc-evm-relay: Optimized gasless relayer orchestration.
• grant / faucet: Cold-start overrides and sponsored access.
• Legacy aliases like x402-direct are transparently normalized internally.

Observable Commerce / Authorization Surfaces (Inspect-Only):

• AP2 (Agent Payments Protocol): Detected via payment/checkout mandate metadata. Classified as an authorization surface. The SDK does not sign mandates.
• ACP (Agentic Commerce Protocol): Detected via checkout, cart, or delegated payment token metadata. The SDK does not execute ACP checkouts.
• OKX APP: Detected when explicit APP metadata or broker objects are present.
• Card-network / wallet-mediated agent payments: Treated as observable commerce or authorization patterns, not native SDK execution targets.

🚀 Initializing with Dual-Stack Keys (EVM & SVM)

For agents operating across both Ethereum and Solana ecosystems, the SDK strictly isolates key handling to prevent parsing collisions.

from ln_church_agent import Payment402Client, PaymentPolicy
import os

client = Payment402Client(
    private_key=os.getenv("EVM_PRIVATE_KEY"),        # For standard x402 EVM
    svm_private_key=os.getenv("SVM_PRIVATE_KEY"),    # For standard x402 SVM Exact
    svm_rpc_url=os.getenv("SOLANA_RPC_URL", "https://api.devnet.solana.com"),
    policy=PaymentPolicy(...)
)

⚠️ SVM Exact Architecture & Constraints:

• svm_private_key must be a standard 64-byte Base58 encoded Solana key.

• The SVM exact path is distinct from the legacy lnc-solana-transfer route and responds strictly to scheme: "exact" + network: "solana:<genesisHash>".

• Wire-Level Precision: The transaction builder preserves and uses the raw PaymentRequirements.asset (SPL Token Mint Address) and raw amount (minimal units) for wire-level transaction construction. Human-readable normalization is only used internally for policy and budget evaluation.

• ATA Constraint: The Destination Associated Token Account (ATA) must already exist. The current SDK transaction builder does not inject ATA creation instructions.

• Supported Mints: The internal builder currently targets strictly known USDC mints. Unknown mints will be rejected due to unknown decimals.

• Safety: Always validate your agent's negotiation flow on Solana Devnet before committing real liquidity on Mainnet.

• Architecture Note: Due to the current lack of a public low-level transaction builder in the official Python SDK, this runtime utilizes a Local SVM Exact Transaction Builder to construct standardized VersionedTransaction payloads.

• Interop Validation: This implementation has been successfully validated against a live Hono x402 gateway (@x402/svm) on Solana Mainnet (USDC), successfully negotiating a full 402 gasless settlement.

🎟️ Two LN Church Onboarding Paths (Cold-Start Overrides)

While direct settlement (x402/L402/MPP) remains the standard paid path, LN Church provides two onboarding paths for cold-start execution and sandbox testing. Both act as a paymentOverride before standard settlement.

1. Zero-Balance Faucet Fallback

A one-time fallback for agents with no available cryptocurrency. Designed strictly for initial capability verification.

from ln_church_agent import LnChurchClient, AssetType

client = LnChurchClient(
    private_key="0x...",  # identity anchor for canonical agent binding
    ln_provider="alby",
    ln_api_key="token",
)
client.init_probe()
client.claim_faucet_if_empty()

result = client.draw_omikuji(asset=AssetType.SATS) # Uses Faucet override

2. Sponsored Grant Access

Execute using a signed, scoped, single-use grant token issued by a trusted sponsor. This serves as an experimental foundation for sponsor-funded pre-payment distribution in A2A settings.

ln-church-agent v1.8.3 can locally diagnose a grant token before use (client.explain_grant()), explaining whether it appears usable for the target route/method/audience/agentId. This diagnostic is advisory only; the LN Church backend remains the authoritative validator and enforces single-use consumption.

from ln_church_agent import LnChurchClient

client = LnChurchClient(
    private_key="0x...",  # identity anchor for canonical agent binding
    base_url="https://kari.mayim-mayim.com",
)
client.init_probe()

client.set_grant_token("<JWS_GRANT_TOKEN>")
result = client.draw_omikuji()  # Uses Grant override

📜 Standards Tracking Policy

This SDK is designed to follow the evolving open standards around HTTP 402 agent payments, ensuring application developers do not need to track each protocol directly.

• Normative Upstream References: Coinbase x402, IETF draft-ryan-httpauth-payment-01 (MPP), and Lightning Labs L402.
• Tracking Policy: This SDK prioritizes the current standard path for each protocol. Legacy and ecosystem-specific flows remain available as fallback compatibility paths.
• Design Goal: One SDK, one execution loop, multiple 402 payment rails.

When upstream standards evolve, this SDK aims to absorb those changes behind a stable developer-facing interface. If you use this SDK, you should not need to manually follow every protocol revision in the 402 ecosystem.

Note on Evolving MPP Standards: ln-church-agent does not attempt to replace official MPP SDKs. Instead, it focuses on buyer-side runtime concerns: policy checks, challenge parsing, payment-shape telemetry, evidence capture, and interop observation across L402, x402, and emerging MPP-style Payment challenges. For instance, MPP session intent is currently actively observed and classified for telemetry, but not executed as a full runtime flow.

⚖️ Advisor & Final Judge Architecture

Agents can consult the Monzen network as an evidence-rich advisor to assess counterparty risk before paying, and to verify semantic outcomes after execution.

Crucially, the network can advise, but final authority remains in the local runtime. The LN Church backend returns structured recommendations (e.g., Sanctification status, historical mismatches), but the SDK's local PaymentPolicy and allowed_hosts configuration will always explicitly supersede remote advice.

📡 Verified Domain Track Lite Workflow

Register a domain for the public-safe observation track and establish sponsorship proof via the CLI.

# 1. Register and pay (19 USDC)
ln-church-agent observe-domain track register kari.mayim-mayim.com \
  --pay \
  --max-spend-usd 25 \
  --proof-file .ln-church/vdt-kari-proof.json

# 2. Generate sponsor challenge file
ln-church-agent observe-domain sponsor challenge obsreq_123 \
  --proof-file .ln-church/vdt-kari-proof.json \
  --output-file .well-known/ln-church-domain-sponsor.json

# (Host the generated file at your domain's /.well-known/ path)

# 3. Verify sponsorship
ln-church-agent observe-domain sponsor verify obsreq_123 \
  --proof-file .ln-church/vdt-kari-proof.json

# 4. Check status
ln-church-agent observe-domain track status obsreq_123

Confirm the proof file exists locally.

This file contains result_handle/request_hash material.

Do NOT publish it. Do NOT commit it.

test -f .ln-church/vdt-kari-proof.json

Confirm the public challenge document is reachable after publishing.

curl -I https://kari.mayim-mayim.com/.well-known/ln-church-domain-sponsor.json

Confirm the verified track status.

ln-church-agent observe-domain track domain kari.mayim-mayim.com

Test-Path ".ln-church/vdt-kari-proof.json"

curl.exe -I "https://kari.mayim-mayim.com/.well-known/ln-church-domain-sponsor.json"

ln-church-agent observe-domain track domain kari.mayim-mayim.com

📚 Further Documentation

• Quickstart & Authentication
• Architecture & Capabilities
• The LN Church Pilgrimage
• Integrations (MCP & LangChain)
• Monzen Observation Network

License

MIT