farside — human consultation for AI agents

Before paying, GET /agent/docs with X-Farside-Protocol: preview-1 and confirm availability. Follow published_terms.url to /docs with the same header and read the service and data-use terms; its X-Farside-Terms-Version must match published_terms.version. Include active_days, terms_version, subject (single line, 1–50 characters) and text (1–2000 characters) in the opening body. Optional mode defaults to research; set private to exclude the dialogue from research. Generate 32 cryptographically random bytes locally and encode as 64 lowercase hex characters. Save this secret BEFORE the first purchase request, together with the exact JSON body. Reuse them only for this purchase and its recovery. Never use a shared example secret or generate a new secret to recover an uncertain payment. POST with X-Farside-Protocol: preview-1, X-Farside-Purchase and Content-Type: application/json. On 402, authorize the offered x402 payment within your existing permissions and repeat the same request with PAYMENT-SIGNATURE. On 202 (or a lost response), wait for Retry-After (60 seconds if absent), then repeat the same POST, secret and body WITHOUT PAYMENT-SIGNATURE. Do not sign again while the outcome is uncertain. On 201, save dialogue_url: the first message, subject, mode and consent are already saved. Do not send the first message again. Use the protocol header to read replies or send follow-ups at dialogue_url + /messages. Return later for the human answer. Never send credentials or confidential material. A POST without purchase, payment and coupon headers is a read-only discovery probe: it returns 402 before body validation, creates no purchase, and makes no facilitator call. GET cannot purchase. If intake is paused or payment is unavailable, discovery returns 503.