Contract capability intersection
Intersect 2–8 supplied capability offers, exact protocol/version/media identifiers and bounded size intervals. Return a deterministic common proposal or explicit conflicts; no negotiation, schema compatibility proof or authorization occurs.
workflow-assurance · Operation ID: contract-capability-negotiate
Choose this operation when
- Find a common contract version and declared capabilities between agents
- Compare message and batch limits before exchanging artifacts
Outside this profile
- Live negotiation, message delivery, queue consumption, remote pagination, artifact fetching or migration execution
- Authentication, signed provenance, authorization, schema compatibility proofs, or exactly-once guarantees
- Inferring absent versions, server state, missing history, semantic equivalence, or market uniqueness
Exact release references
Static JSON contract · Markdown reference · Fixed example response
Complete input schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"offers": {
"minItems": 2,
"maxItems": 8,
"type": "array",
"items": {
"type": "object",
"properties": {
"party": {
"type": "string",
"minLength": 1,
"maxLength": 100
},
"protocol": {
"type": "string",
"minLength": 1,
"maxLength": 100
},
"versions": {
"minItems": 1,
"maxItems": 32,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"mediaTypes": {
"minItems": 1,
"maxItems": 16,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"capabilities": {
"maxItems": 32,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"requiredCapabilities": {
"maxItems": 32,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"minimumMessageBytes": {
"type": "integer",
"minimum": 1,
"maximum": 100000000
},
"maximumMessageBytes": {
"type": "integer",
"minimum": 1,
"maximum": 100000000
},
"minimumBatchItems": {
"type": "integer",
"minimum": 1,
"maximum": 10000
},
"maximumBatchItems": {
"type": "integer",
"minimum": 1,
"maximum": 10000
}
},
"required": [
"party",
"protocol",
"versions",
"mediaTypes",
"capabilities",
"requiredCapabilities",
"minimumMessageBytes",
"maximumMessageBytes",
"minimumBatchItems",
"maximumBatchItems"
],
"additionalProperties": false
}
}
},
"required": [
"offers"
],
"additionalProperties": false
}
Complete output-envelope schema
{
"type": "object",
"required": [
"operation",
"version",
"result",
"provenance"
],
"properties": {
"operation": {
"const": "contract-capability-negotiate",
"type": "string"
},
"version": {
"const": "0.29.0",
"type": "string"
},
"result": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"profile": {
"type": "string",
"const": "contract-capability-intersection-v1"
},
"compatibleDeclarations": {
"type": "boolean"
},
"protocol": {
"anyOf": [
{
"type": "string",
"minLength": 1,
"maxLength": 100
},
{
"type": "null"
}
]
},
"commonVersions": {
"maxItems": 32,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"commonMediaTypes": {
"maxItems": 16,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"commonCapabilities": {
"maxItems": 32,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"requiredCapabilities": {
"maxItems": 256,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
},
"selection": {
"anyOf": [
{
"type": "object",
"properties": {
"version": {
"type": "string",
"minLength": 1,
"maxLength": 100
},
"mediaType": {
"type": "string",
"minLength": 1,
"maxLength": 100
},
"minimumMessageBytes": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"maximumMessageBytes": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"minimumBatchItems": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"maximumBatchItems": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
}
},
"required": [
"version",
"mediaType",
"minimumMessageBytes",
"maximumMessageBytes",
"minimumBatchItems",
"maximumBatchItems"
],
"additionalProperties": false
},
{
"type": "null"
}
]
},
"selectionPolicy": {
"type": "string",
"const": "lexicographic-first-version-and-media-type"
},
"findings": {
"maxItems": 200,
"type": "array",
"items": {
"type": "object",
"properties": {
"code": {
"type": "string"
},
"severity": {
"type": "string",
"enum": [
"error",
"warning"
]
},
"path": {
"type": "string"
},
"message": {
"type": "string"
},
"relatedIds": {
"maxItems": 8,
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"maxLength": 100
}
}
},
"required": [
"code",
"severity",
"path",
"message",
"relatedIds"
],
"additionalProperties": false
}
},
"findingCount": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"errorCount": {
"type": "integer",
"minimum": 0,
"maximum": 9007199254740991
},
"truncated": {
"type": "boolean"
},
"advisoryOnly": {
"type": "boolean",
"const": true
},
"execution": {
"type": "boolean",
"const": false
},
"authorizationGranted": {
"type": "boolean",
"const": false
}
},
"required": [
"profile",
"compatibleDeclarations",
"protocol",
"commonVersions",
"commonMediaTypes",
"commonCapabilities",
"requiredCapabilities",
"selection",
"selectionPolicy",
"findings",
"findingCount",
"errorCount",
"truncated",
"advisoryOnly",
"execution",
"authorizationGranted"
],
"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
{
"offers": [
{
"party": "producer",
"protocol": "agent-exchange",
"versions": [
"1",
"2"
],
"mediaTypes": [
"application/json"
],
"capabilities": [
"cursor",
"digest"
],
"requiredCapabilities": [
"digest"
],
"minimumMessageBytes": 1,
"maximumMessageBytes": 65536,
"minimumBatchItems": 1,
"maximumBatchItems": 32
},
{
"party": "consumer",
"protocol": "agent-exchange",
"versions": [
"2"
],
"mediaTypes": [
"application/json"
],
"capabilities": [
"cursor",
"digest"
],
"requiredCapabilities": [
"digest"
],
"minimumMessageBytes": 1,
"maximumMessageBytes": 32768,
"minimumBatchItems": 1,
"maximumBatchItems": 32
}
]
}
Example response
{
"operation": "contract-capability-negotiate",
"version": "0.29.0",
"result": {
"profile": "contract-capability-intersection-v1",
"compatibleDeclarations": true,
"protocol": "agent-exchange",
"commonVersions": [
"2"
],
"commonMediaTypes": [
"application/json"
],
"commonCapabilities": [
"cursor",
"digest"
],
"requiredCapabilities": [
"digest"
],
"selection": {
"version": "2",
"mediaType": "application/json",
"minimumMessageBytes": 1,
"maximumMessageBytes": 32768,
"minimumBatchItems": 1,
"maximumBatchItems": 32
},
"selectionPolicy": "lexicographic-first-version-and-media-type",
"findings": [],
"findingCount": 0,
"errorCount": 0,
"truncated": false,
"advisoryOnly": true,
"execution": false,
"authorizationGranted": false
},
"provenance": {
"inputSha256": "4fb7645310512b039a130583f3563bf82879d9a262987e2fe833361cb966f2e6",
"outputSha256": "92caafb7a800cd6179eff138af48895244dd681561014116a3f810cf850bcdf0",
"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": 200,
"parties": 8,
"versionsPerParty": 32,
"capabilitiesPerParty": 32
}
}
Complete schemas, descriptions and cross-field validation may impose additional limits.
Proposed price and protocol definitions
{
"unit": "one successful operation call",
"proposedNominalUsd": "0.005",
"sixDecimalTokenBaseUnits": "5000",
"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/contract-capability-negotiate",
"mpp": "/v1/mpp/contract-capability-negotiate"
}
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.