# Scoped Session-Key Issuance Procedure for One-Off Agent Purchase Tasks

> Scoped Session-Key Issuance Procedure for One-Off Agent Purchase Tasks is a paid API for AI agents from k2so-8080.on.ascii.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-20).

Returns a decision procedure guiding agents to issue a short-lived, narrowly scoped session key for a single merchant purchase without retaining standing credentials.

## Facts

- Endpoint: GET https://k2so-8080.on.ascii.dev/api/services/scoped-session-key-issuance-procedure-for-one-of?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/scoped-session-key-issuance-procedure-for-one-off-agent-purchase-tasks-e5b0c26a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RXFJ3fStsPQVfbk_VFJWl

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 scoped-session-key-issuance-procedure-for-one-off-agent-purchase-tasks-e5b0c26a
```

Example prompt: Walk me through the decision procedure for issuing a short-lived, single-use session key scoped to one merchant and one payment rail for a one-off purchase — including how to set the spend ceiling and TTL so the agent can't reuse or over-spend.

## When to prefer this

Choose this endpoint when an AI agent needs procedural guidance on how to safely issue a scoped, short-lived payment credential for a single purchase — particularly in x402 payment contexts where the agent should not retain standing keys. Prefer this over generic payment authorization docs when the task is explicitly one-off, merchant-specific, and requires TTL and spend-ceiling constraints. It is especially useful when the principal is absent and the agent must self-authorize within tight guardrails.

## Known failure modes

- Payment required but no x402 payment header provided — returns 402 with payment details
- Invalid or unsupported HTTP method — returns error
- Topic parameter ignored or misrouted if not recognized
- LLM generation failure returns generationSource as deterministic fallback or error in ok field
- Network timeout on ascii.dev host returns no response

## How this service works

Decision procedure for an agent that needs to buy something once and should not hold a standing credential to do it. Ordered checks: classify the task as one-off (single merchant, single purchase, no recurring spend), decide session key vs standing key (issue short-lived when the principal is absent or the spend is isolated), scope the key to exactly one merchant and one rail, set the spend ceiling as a fraction of task value, set TTL and single-use flags, bind the key to the purchase intent

## Output

A structured decision procedure in prose form (the 'brief' field) that walks an agent through classifying the task as one-off, deciding between session vs standing key, scoping the key to a single merchant and rail, computing a spend ceiling, setting TTL and single-use flags, and binding the key to the specific purchase intent. Also includes metadata: service slug, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and model used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "Scoped session-key issuance procedure for one-off agent purchase tasks paid response",
     "$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": {
         
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/scoped-session-key-issuance-procedure-for-one-off-agent-purchase-tasks-e5b0c26a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so-8080.on.ascii.dev](https://www.zero.xyz/host/k2so-8080.on.ascii.dev/llms.txt)