x402 Solana Pulse

Real-time payment protocol analytics for Coinbase x402 on Solana

Track every x402 payment settlement on Solana — both schemes. This Substreams detects facilitator-sponsored settlements for HTTP 402 payments and extracts payer, recipient, mint, amount, facilitator and memo from each one.

Scheme	Shape on chain	Covered
exact	SPL Token TransferChecked at top level	since v1.0
upto	payment-channels program, transfer as a CPI	new in v1.2

Every row carries scheme, so you can filter to one or trust the total. That matters more than it sounds: upto settlements have no top-level TransferChecked at all, so any Solana x402 indexer that only walks top-level instructions silently undercounts them and looks complete while doing it.

Companion to x402-base-pulse — same model, Solana native.

---

How It Works

The x402 protocol enables internet-native payments using the HTTP 402 status code. The Solana settlement path is defined by the SVM exact scheme:

1. Server responds with HTTP 402 + payment requirements (mint, payTo, amount, feePayer)
2. Client constructs a transaction containing a TransferChecked to the resource server's ATA, signs it, and returns the partially-signed tx
3. Facilitator verifies the transaction, provides the final feePayer signature, and submits it to Solana
4. Solana executes an SPL Token (or Token-2022) TransferChecked + SPL Memo instruction
5. This Substreams captures those transactions by looking for the x402 SVM settlement shape

The upto scheme is shaped differently

upto settles through the payment-channels program (CHNLxYvVA28MJP9PrFuDXccuoGXAx7jBacfLEkahyGsX) rather than a direct transfer. Observed on mainnet, the transaction looks like:

top-level : [ComputeBudget, ComputeBudget, PAYMENT_CHANNELS, Memo]
inner CPI : SPL TransferChecked     <- the actual token movement

Two consequences worth knowing before you query:

• The transfer is a CPI, so it never appears among top-level instructions. A detector that only walks those will report zero upto volume rather than an error.
• The inner transfer's authority is the channel PDA, not the end payer. Those rows set scheme='upto' and carry the PDA in both payer and channel, so you always know which one you are holding instead of mistaking a channel for a wallet.

Detection: strict spec match + known-facilitator fallback

Solana has no on-chain FacilitatorRegistry. This substreams uses a two-layer approach:

1. Strict spec match (any facilitator, known or new): Matches the SVM exact scheme layout verbatim — 3–6 top-level instructions consisting of ComputeBudget SetLimit, ComputeBudget SetPrice, TransferChecked, then optional Memo / Lighthouse. Fee payer must differ from the TransferChecked authority. This captures any spec-compliant facilitator automatically, including new ones that haven't been added to the allowlist.

2. Relaxed match for known facilitators: For the 21 facilitator pubkeys mirrored from x402scan's registry, we accept looser layouts (TransferChecked + Memo anywhere in top-level instructions) so non-spec variants still get indexed. Known facilitators include: Coinbase, PayAI, Dexter, Daydreams, OpenX402, AnySpend, CodeNut, Corbits, Aurracloud, Bitrefill, Cascade, OpenFacilitator, Relai, UltravioletaDAO, X402Jobs.

Splitting volume by scheme

SELECT scheme, COUNT(*) AS settlements, SUM(amount::numeric) AS volume
FROM settlements
GROUP BY scheme;

Channel activity, for upto only:

SELECT channel, COUNT(*) AS settlements, SUM(amount::numeric) AS volume
FROM settlements
WHERE scheme = 'upto'
GROUP BY channel
ORDER BY volume DESC;

Discovering new facilitators

Every settlement has facilitator_name (empty if unknown) and facilitator_known (boolean). To find new facilitators to add to the allowlist:

SELECT facilitator, COUNT(*) AS tx_count, SUM(amount) AS volume
FROM settlements
WHERE facilitator_known = false
GROUP BY facilitator
ORDER BY tx_count DESC
LIMIT 20;

High-volume unknown fee-payers are candidates. Verify on Solscan, then add to KNOWN_FACILITATORS in src/lib.rs and publish a new version.

Modules

Module	Kind	Description
map_x402_settlements	Map	Detects x402 settlements in each Solana block and extracts payer / recipient / mint / amount / facilitator / memo
store_payer_volume	Store	Accumulates total amount spent per payer pubkey
store_payer_count	Store	Counts payments per payer
store_recipient_volume	Store	Accumulates total received per resource server (ATA owner)
store_recipient_count	Store	Counts payments per recipient
store_facilitator_volume	Store	Accumulates volume settled per facilitator
store_facilitator_count	Store	Counts settlements per facilitator
store_facilitator_fees	Store	Accumulates tx fees (lamports) paid per facilitator
store_first_seen	Store	Records first-seen block timestamp per payer / recipient / facilitator
map_payer_stats	Map	Computes payer leaderboards and averages
map_recipient_stats	Map	Computes resource server revenue stats
map_facilitator_stats	Map	Computes facilitator economics (volume, fees, counts)
db_out	Map	Outputs DatabaseChanges for the PostgreSQL sink

Programs Indexed

Program	Pubkey
SPL Token	TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA
SPL Token-2022	TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb
SPL Memo v2	MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr
SPL Memo v1	Memo1UhkJRfHyvLMcVucJwxXeuD728EqVDDwQDxFMNo

Quick Start

# Stream settlements
substreams run x402-solana-pulse map_x402_settlements \
  -e mainnet.sol.streamingfast.io:443 \
  -s 280000000 -t +1000

# GUI mode
substreams gui x402-solana-pulse map_x402_settlements \
  -e mainnet.sol.streamingfast.io:443 \
  -s 280000000

# Sink to PostgreSQL
substreams-sink-sql run "psql://localhost/x402" \
  x402-solana-pulse-v1.0.0.spkg \
  -e mainnet.sol.streamingfast.io:443

SQL Output

Tables

Table	Key	Description
settlements	signature-instruction_index	Every settlement with payer, recipient, mint, amount, facilitator, fee, memo
payers	payer_address	Aggregated spend and payment count per payer pubkey
recipients	recipient_address	Revenue and payment count per resource server
facilitators	facilitator_address	Volume settled, settlement count, lamport fees per facilitator

Views

View	Description
daily_stats	Daily protocol-wide volume, unique participants, fees
top_payers	Ranked by total spend
top_recipients	Ranked by total revenue
facilitator_economics	Volume settled vs fee cost per facilitator
whale_payments	Payments ≥ 100 USDC (atomic units)
recent_settlements	Latest 100 settlements

Build

cargo build --target wasm32-unknown-unknown --release
substreams pack substreams.yaml

References

• x402 Protocol — Coinbase's HTTP 402 payment standard
• How It Works — Settlement flow
• SVM exact scheme — Solana settlement spec
• Network Support — Supported tokens and chains
• x402 Source — Protocol implementation
• x402-base-pulse — Companion Base substreams

Network

• Chain: Solana mainnet
• Endpoint: mainnet.sol.streamingfast.io:443
• Initial block: 280,000,000 (adjustable)