Give FAHCE a candidate answer and the evidence available to your agent. FAHCE identifies unsupported claims, contradictory records, missing proof and reported actions not established by the submitted evidence. Receive a structured determination, proposed corrections when appropriate, verification state and a content-hashed receipt.
Read the machine contract, choose an operation, submit your evidence, pay with a compatible x402 wallet, and retain the full result and payment receipts.
Check an AI-generated answer against supplied evidence. Identify unsupported claims, contradictions, missing proof, and reported actions that the available records do not establish.
You need to understand what the supplied evidence establishes.
$0.15 fixed · x402 exact
Actual settlement: $0.15 fixed. Paid-path purchase acceptance demonstrated; independent transfer reconciliation remains separate.
POST https://fahce.kinganlogic.com/api/v1/diagnoseRequest and response contractEvaluate an integrity problem and return a bounded, evidence-preserving correction plan when supported. Proposed corrections are not executed in the customer's systems.
An identified deficiency needs a scoped correction with prerequisites and protected evidence.
$0.15 fixed · x402 exact
Actual settlement: $0.15 fixed. Paid-path purchase acceptance demonstrated; independent transfer reconciliation remains separate.
POST https://fahce.kinganlogic.com/api/v1/repairRequest and response contractRecheck a submitted or revised answer against supplied evidence. Return a scoped verification determination and content-hashed receipt without claiming independent external execution.
A claimed fix or completed action needs evidence-bound review.
$0.15 fixed · x402 exact
Actual settlement: $0.15 fixed. Paid-path purchase acceptance demonstrated; independent transfer reconciliation remains separate.
POST https://fahce.kinganlogic.com/api/v1/verifyRequest and response contractReceive diagnosis, a bounded proposed repair when required, verification state, and a receipt in one paid response. Authorize up to $0.39; eligible outcomes may settle at $0, $0.15, or $0.39.
You need the connected diagnosis, proposed correction and current verification state in one determination.
$0.39 maximum authorization · x402 upto
Actual settlement: $0.15 without repair required; $0.39 with repair required. Paid-path purchase acceptance demonstrated; independent transfer reconciliation remains separate.
POST https://fahce.kinganlogic.com/api/v1/repair-bundleRequest and response contractUse your x402 v2 wallet client for paid requests. No pilot key or prior account is required.
Submit JSON directly to an operation endpoint, and use /mcp to discover the contract. Paid REST calls use wallet-only x402 authorization, with no human sign-in or issued key. MCP discovers tools; paid execution uses the corresponding REST URLs.
Idempotency-Key is optional. If supplied, keep it unchanged for the same purchase; changed input needs a new purchase identity. Existing receipt reads consume no determination quota.
Individual operations use fixed-price x402 payments of $0.15 each. Bundle uses a maximum authorization of $0.39 and settles the eligible amount determined by the operation. An authorization ceiling is not necessarily the amount transferred.
Diagnose, Repair and Verify cost $0.15 fixed each. The Full Repair Cycle authorizes up to $0.39: settle $0 for nonbillable free retry, $0.15 for verified no-repair work, or $0.39 for a required validated bounded plan. Three separate billable Diagnose, Repair and Verify calls total $0.45. Bundle HTTP 402 requests the $0.39 ceiling even when the eligible actual amount is lower. Unrecognized proposition forms are non-billable and receive an explicit free-retry outcome. Held/invalid plans and unsupported processing are nonbillable; a completed negative Verify is billable; exact-scheme gateway charging on HTTP errors remains unverified.
An up-to amount is a ceiling. The bundle is one logical determination; its stages do not create separate service calls.
Submit candidate-output text, optional expected-output text, and up to 12 caller-supplied log, paste, document (text only) or description items. Bind identities, timestamps, provenance and execution context in the actual evidence text. Source labels alone do not establish trusted authority. This API does not interpret binary PDFs/images, fetch arbitrary websites or execute external repairs.
The entire UTF-8 encoded JSON body must fit within 524288 bytes (512 KiB), including all fields, labels, escaping and JSON overhead. Per-field maxima are independent ceilings; they cannot all be used at once. MCP includes its JSON-RPC wrapper in the same body ceiling. Character limits are UTF-16 code units.
Replace the placeholders with your actual candidate output and source evidence.
{
"schema": "FAHCE_MACHINE_REQUEST_V1",
"candidate_output": "<your exact candidate answer>",
"evidence": [
{
"id": "source_1",
"kind": "log",
"source_label": "<caller-supplied source label>",
"text": "<original evidence>"
}
]
}curl 'https://fahce.kinganlogic.com/api/v1/diagnose' \ -H 'Content-Type: application/json' \ -H 'Idempotency-Key: <high-entropy-request-key-at-least-32-characters>' \ --data-binary @request.json
expected_output: Optional response-contract and repair-target context for all operations, including Diagnose. Supported response-format directives (for example, Return JSON) and implemented explicit constraints can affect the diagnosis. Ordinary matching or mismatching factual text is not compared for string equality and is not a trusted answer oracle or supporting evidence; supply independent evidence for factual claims.
Retain the returned request_id and receipt hashes. Read the saved response at /api/v1/receipts/{receipt_id} using the returned request_id UUID and Authorization: FAHCEReceipt <FAHCE-Recovery-Token>. The capability only reads that receipt, consumes no new payment and grants no operation or owner authority.
Preserve the entire returned JSON body, including receipt.input_hash, receipt.result_hash, receipt.response_hash and its hash scheme. Keep the separate gateway PAYMENT-RESPONSE and purchase identity. Store the private FAHCE-Recovery-Token securely. Recover with GET /api/v1/receipts/{receipt_id} and Authorization: FAHCEReceipt <token>, or POST /api/v1/machine/recovery with the scoped recovery credential. A public request ID, wallet address or hash does not authorize private retrieval. Reconcile ambiguous payment or delivery before another purchase. Complete custody and recovery instructions.
For a completed determination, response.request_id is the receipt_id UUID and equals receipt.case_id and receipt.run_id. Error-envelope request_id is an HTTP trace; use error.receipt_id when present. Each receipt binds input/evidence hashes, engine version and response hash. Supply prior-case context as evidence text; this contract does not automatically load a human case or prior repair. Immutable origin charge fields remain null. Retain the gateway PAYMENT-RESPONSE separately; automated provider reconciliation is unverified; separately proven evidence is recorded through authorized accounting review.
The result distinguishes claim support, conflicts, missing evidence, permission, asserted execution, provable execution and proposed repair. A held or unresolved result identifies what evidence is needed next.
request the operation; read the gateway's HTTP 402 PAYMENT-REQUIRED; authorize payment with an x402 v2 client; retry the same bound request using PAYMENT-SIGNATURE. No pilot key, invitation or prior account is required. The verified payment creates a machine-only principal for this operation. Before authorizing payment, review the published policies and send FAHCE-Terms-Accepted with their legal_documents.publication_hash on the bound request. Retain the random FAHCE-Recovery-Token for free recovery. It authorizes only this purchase's retained output and is not a refund or execution credential. If the first response is lost before the token arrives, original-purchase evidence must be verified separately; do not buy again automatically. The origin verifies the gateway-signed PAYMENT-CONTEXT; PAYMENT-SETTLEMENT is an origin-to-gateway instruction for upto only. Exact responses omit that instruction. The gateway returns PAYMENT-RESPONSE after settlement. Origin delivery intents are not charge receipts. Paid MCP execution uses the REST URLs.
Paid-path HTTP 200 purchase acceptance has been demonstrated for all four operations; independent transfer reconciliation remains separate. Discovery, schemas, pricing and documentation are free. No browser checkout is required for the published x402 flow.
FAHCE evaluates caller-supplied evidence. Evidence labels do not independently authenticate the source. Proposed repairs are not executed. FAHCE does not certify that a deployment, transfer, browser action, external repair, or other real-world activity occurred.
FAHCE application errors use a JSON envelope. Upstream WAF, Access or transport rejection can occur before the application and return HTML or another non-JSON response, including when Accept is application/json. Machine clients must inspect HTTP status and Content-Type before decoding and must never interpret a security block as an integrity determination. Security protections remain enforced.
Payment authorizes service access; it does not establish claim correctness, external execution or permission to act.
Machine contract 1.4.0: public catalog and content negotiation, published service prices, bounded settlement and explicit execution-state output.
MCP and REST are implemented. A2A, OAuth, external registry publication and a confirmed Bazaar listing are unavailable. Service policies are published. Support: logan@kinganlogic.com. Security: logan@kinganlogic.com.