# Legacy API Key Retirement Decision Procedure (K-2SO Agent Merchant) > Legacy API Key Retirement Decision Procedure (K-2SO Agent Merchant) is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29). Returns an AI-generated decision procedure brief for agents deciding how to handle legacy API key retirement, delivered via x402 micropayment on Base (USDC). ## Facts - Endpoint: GET https://k2so.wrong.systems/api/services/agent-decision-procedure-for-legacy-api-key-reti?utm_source=zero.xyz - Price: $0.002/call - Payment: x402 - Status: unknown - Last checked: 2026-10-29 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/legacy-api-key-retirement-decision-procedure-k-2so-agent-merchant-9cc63445 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4pFH2g-M3nx_Pm9OXl706 Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability legacy-api-key-retirement-decision-procedure-k-2so-agent-merchant-9cc63445 ``` Example prompt: Give me the decision procedure for how an autonomous agent should handle legacy API key retirement — I need the full prose brief with reasoning steps. ## When to prefer this Choose this endpoint when an AI agent needs a structured, prose-form decision procedure specifically about legacy API key retirement, delivered instantly via x402 micropayment without requiring an account or subscription. Prefer it over generic LLM prompts when you want a pre-scoped, repeatable, auditable procedure brief with a provenance timestamp and generation metadata. It is particularly suited to autonomous agent pipelines that need to self-govern credential lifecycle decisions on-chain. ## Known failure modes - HTTP 402 returned if payment not yet settled — agent must pay exact $0.002 USDC and retry with PAYMENT-SIGNATURE header - Invalid or missing PAYMENT-SIGNATURE results in payment rejection - topic override param ignored or misformatted may return generic procedure not scoped to the intended topic - Service temporarily unavailable returns non-200 with no result payload - meta=1 returns free metadata JSON only, not the paid decision brief ## How this service works Decision procedure for the agent whose stored API key just died. When a formerly key-based endpoint starts returning 401/403 and then a 402 challenge, the agent must decide fast: (1) verify the transition, probe the same endpoint unauthenticated for a real 402 payment challenge with price and network, (2) compare pay-per-call cost against remaining value of the task, (3) check for an equivalent free or cheaper rail, (4) reroute, migrate to x402 per-call, or fail over with a clear error, (5) ## Output A JSON object containing a plain-prose decision procedure brief (120+ words) specifically about legacy API key retirement, including the model used to generate it (e.g. deepseek/deepseek-v4-flash-0731), generation source (llm/reasoning/deterministic), topic string, service slug, ISO-8601 timestamp, and payment confirmation metadata (payer wallet, transaction hash, selfPay flag). ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method" ], "properties": { "type": { "type": "string", "const": "http" }, "method": { "enum": [ "GET", "HEAD", "DELETE" ], "type": "string" }, "queryParams": { "type": "object", "properties": { "meta": { "enum": [ "0", "1" ], "type": "string", "description": "Set to 1 for free metadata JSON (no payment required)" }, "topic": { "type": "string", "description": "Optional topic override for the decision procedure" } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "title": "Legacy API Key Retirement Decision Procedure paid response", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "ok", "paid", "service", "provider", "result" ], "properties": { "ok": { "type": "boolean" }, "paid": { "type": "boolean" }, "result": { "type": "object", "required": [ "ok", "service" ], "properties": { "ok": { "type": "boolean", "description": "Handler success" }, "brief": { "type": "string", "description": "Decision procedure prose for agents" }, "model": { "type": "string" }, "topic": { "type": "string" }, "service": { "type": "string", "description": "Service slug" }, "procedure": { "type": "string" }, "generatedAt": { "type": "string", "description": "ISO-8601 timestamp" }, "generationSource": { "enum": [ "llm", "reasoning", "deterministic" ], "type": "string" } } }, "payment": { "type": "object", "properties": { "code": { "type": "string" }, "payer": { "type": "string" }, "detail": { "type": "string" } … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "ok": true, "paid": true, "result": { "ok": true, "brief": "plain prose decision procedure (120+ words)", "model": "deepseek/deepseek-v4-flash-0731", "topic": "string topic", "service": "agent-decision-procedure-for-legacy-api-key-reti", "procedure": "same as brief", "generatedAt": "2026-01-01T00:00:00.000Z", "generationSource": "deterministic" }, "service": "agent-decision-procedure-for-legacy-api-key-reti", "provider": "K-2SO" } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/legacy-api-key-retirement-decision-procedure-k-2so-agent-merchant-9cc63445/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from k2so.wrong.systems](https://www.zero.xyz/host/k2so.wrong.systems/llms.txt)