Scalar URI Template Expansion
Expand RFC6570 scalar string variables with simple, reserved, fragment, label, path, path-parameter and query operators. Explicitly rejects prefix/explode modifiers, lists/maps and non-ASCII variable names/literals. Missing/null variables are omitted with an audit list; no URL fetch, safety verdict or encoding guesswork.
protocol-assurance · Operation ID: uri-template-expand
Choose this operation when
- Expand scalar RFC6570 API URL templates without accidental slash or query injection
- Construct path and query expressions with explicit reserved expansion
Outside this profile
- Full RFC6570 level 4, prefix/explode/list/map expansions or arbitrary Unicode template literals
- URL authorization, host allowlisting, SSRF safety or fetching
Exact release references
Static JSON contract · Markdown reference · Fixed example response
Complete input schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"template": {
"type": "string",
"maxLength": 10000
},
"variables": {
"type": "object",
"propertyNames": {
"type": "string"
},
"additionalProperties": {
"anyOf": [
{
"type": "string",
"maxLength": 10000
},
{
"type": "null"
}
]
}
}
},
"required": [
"template",
"variables"
],
"additionalProperties": false
}
Complete output-envelope schema
{
"type": "object",
"required": [
"operation",
"version",
"result",
"provenance"
],
"properties": {
"operation": {
"const": "uri-template-expand",
"type": "string"
},
"version": {
"const": "0.29.0",
"type": "string"
},
"result": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"profile": {
"type": "string",
"const": "rfc6570-scalar-no-modifiers-v1"
},
"expanded": {
"type": "string"
},
"usedVariables": {
"type": "array",
"items": {
"type": "string"
}
},
"omittedVariables": {
"type": "array",
"items": {
"type": "string"
}
},
"unusedVariables": {
"type": "array",
"items": {
"type": "string"
}
}
},
"required": [
"profile",
"expanded",
"usedVariables",
"omittedVariables",
"unusedVariables"
],
"additionalProperties": false
},
"provenance": {
"type": "object",
"required": [
"inputSha256",
"outputSha256",
"deterministic",
"externalRequests"
],
"properties": {
"inputSha256": {
"type": "string",
"pattern": "^[a-f0-9]{64}$"
},
"outputSha256": {
"type": "string",
"pattern": "^[a-f0-9]{64}$"
},
"deterministic": {
"const": true
},
"externalRequests": {
"const": 0
}
}
}
},
"additionalProperties": false
}
Fixed example
One accepted fixed example, not a custom-input trial. No operation runs when this static page is requested.
Example input
{
"template": "https://api.example/items/{id}{?query,cursor}",
"variables": {
"id": "folder/item",
"query": "red blue",
"cursor": null
}
}
Example response
{
"operation": "uri-template-expand",
"version": "0.29.0",
"result": {
"profile": "rfc6570-scalar-no-modifiers-v1",
"expanded": "https://api.example/items/folder%2Fitem?query=red%20blue",
"usedVariables": [
"id",
"query",
"cursor"
],
"omittedVariables": [
"cursor"
],
"unusedVariables": []
},
"provenance": {
"inputSha256": "e1935af27af4ababb587b1266ec5524c79d346c9ddb94bc2e6b72cd351c0942b",
"outputSha256": "6740b12989926a33df7c5ef4d44a32b7360051d4b52553a4c63bbaac6adcb5f9",
"deterministic": true,
"externalRequests": 0
}
}
Bounds and precision
JavaScript IEEE-754 numbers; use strings for large integer IDs/exact decimals where the schema accepts strings. No lossless numeric parsing.
{
"global": {
"requestBytes": 131072,
"responseBytes": 524288,
"jsonDepth": 32,
"jsonNodes": 20000,
"requestsPerMinute": 60,
"paidAttemptsPerMinute": 20,
"idempotencyHours": 24
},
"operation": {
"inputBytes": 100000,
"outputBytes": 400000,
"jsonNodes": 12000,
"depth": 20,
"findings": 150,
"findingJsonBytes": 300000,
"variables": 100,
"expressions": 100,
"templateCharacters": 10000,
"expandedCharacters": 200000
}
}
Complete schemas, descriptions and cross-field validation may impose additional limits.
Proposed price and protocol definitions
{
"unit": "one successful operation call",
"proposedNominalUsd": "0.003",
"sixDecimalTokenBaseUnits": "3000",
"subscription": false,
"includesPayerWalletOrNetworkFees": false,
"liveQuoteVerified": false,
"condition": "Actual SDK challenge is authoritative only within the caller's explicit authorization; configured six-decimal token peg is an operator assertion, not a conversion guarantee."
}
Protocol definitions: x402, mpp. MPP uses Tempo charge. Paid MCP execution is unsupported. All runtime readiness is not evaluated in this build.
API path templates, not endpoints on this documentation host
{
"x402": "/v1/x402/uri-template-expand",
"mpp": "/v1/mpp/uri-template-expand"
}
Required headers
{
"Content-Type": "application/json",
"Idempotency-Key": "random 16–128 character operation identifier"
}
Actual SDK challenge amount, asset, network, recipient and wallet costs must pass independent authorization. Preserve identical key, body, protocol and credential on retries; on PAYMENT_UNCERTAIN stop and reconcile.
Execution profile and provider conditions
{
"deterministic": true,
"externalRequests": 0,
"maxExternalRequests": 0,
"resultSnapshotPersisted": false,
"fixedExampleIsIllustrativeSnapshot": false,
"requiresPayment": true,
"supportsMcpExecution": false
}
Deterministic supplied-input operation with no external requests or stored request/result bodies. Payment infrastructure retains payment metadata and hashes.
Failure handling
- HTTP 400: Malformed JSON, missing/invalid idempotency key, or payment identifier mismatch Correct the request before payment
- HTTP 402: Payment challenge or rejected payment Use official protocol SDK; inspect payment outcome before another payment
- HTTP 409: Idempotency conflict, duplicate proof, or PAYMENT_UNCERTAIN Keep original key, body, and proof; reconcile uncertainty with operator; never blindly repay
- HTTP 413: Input or generated output too large Reduce input; no payment attempted for validation failure
- HTTP 415: Unsupported media type or compression Send uncompressed application/json
- HTTP 422: Schema or service-specific semantic validation failure Correct input using returned error code; no payment attempted
- HTTP 429: Request/payment-attempt rate exceeded Wait for rate limit window; preserve existing payment identity
- HTTP 503: Payment configuration/provider/state unavailable, or live DNS preparation failed before settlement Check readiness; DNS preparation failures may retry the identical key/body/credential only; uncertainty requires reconciliation
Declared requirements
Before any paid call, refresh the live operation contract and POST the complete bounded budgeted plan to the separate API's /preflight. Unknown requirements block selection; compatible preflight is not permission to spend.