Response Schema

Complete JSON response format for each protocol and endpoint type.

Critical: No top-level price field

Oracle responses do not have a top-level price field. The price is embedded in the canonical string at position 2. Extract it with canonical.split("|")[2].

L402 Response (secp256k1)

Returned by the L402 proxy. This is the raw backend response passed through unchanged.

json

{
  "domain": "BTCUSD",
  "canonical": "v1|BTCUSD|84231.50|USD|2|2026-02-28T07:51:00Z|890123|binance,binance_us,bitfinex,bitstamp,coinbase,gateio,gemini,kraken,okx|median",
  "signature": "<base64-DER-encoded-secp256k1-ECDSA>",
  "pubkey": "<33-byte-compressed-hex-secp256k1>"
}

Field	Type	Description
`domain`	string	Pair identifier without slash (e.g., "BTCUSD")
`canonical`	string	Pipe-delimited canonical string that was signed. See format spec →
`signature`	string	Base64-encoded DER signature over SHA-256(canonical)
`pubkey`	string	Compressed secp256k1 public key, hex-encoded (33 bytes)

x402 Response (Ed25519)

Returned by the x402 proxy after successful USDC payment. The canonical string is from the backend, but the signature is re-signed with Ed25519.

json

{
  "domain": "BTCUSD",
  "canonical": "v1|BTCUSD|84231.50|USD|2|2026-02-28T07:51:00Z|890123|binance,...|median",
  "signature": "<base64-raw-ed25519-64-bytes>",
  "signing_scheme": "ed25519",
  "pubkey": "<32-byte-hex-ed25519>"
}

Field	Type	Description
`domain`	string	Pair identifier without slash
`canonical`	string	Pipe-delimited canonical string (same format as L402)
`signature`	string	Base64-encoded raw Ed25519 signature (64 bytes) over SHA-256(canonical)
`signing_scheme`	string	Always `"ed25519"`. Absent in L402 responses.
`pubkey`	string	Ed25519 public key, hex-encoded (32 bytes)

Protocol detection

To determine which signature scheme to use for verification: if the response contains "signing_scheme": "ed25519", use Ed25519. If the field is absent, the signature is secp256k1 ECDSA (L402 path).

402 Payment Required (x402)

json

{
  "x402Version": 1,
  "accepts": [{
    "scheme": "exact",
    "network": "base",
    "maxAmountRequired": "1000",
    "resource": "https://api.myceliasignal.com/oracle/btcusd",
    "description": "BTC/USD spot price — Ed25519-signed attestation",
    "payTo": "0x...",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "maxTimeoutSeconds": 60
  }],
  "error": "X-PAYMENT header is required"
}

402 Payment Required (L402)

The L402 402 response uses the WWW-Authenticate HTTP header rather than a JSON body:

http header

WWW-Authenticate: L402 macaroon="AgELbXljZWxpYS...", invoice="lnbc100n1pj..."

Extracting Data

python

# Extract price from response
price = response["canonical"].split("|")[2]

# Extract sources
sources = response["canonical"].split("|")[7].split(",")

# Extract timestamp
timestamp = response["canonical"].split("|")[5]

← Endpoints & Pairs Canonical Format →