Fallback
Tiny paid recovery and decision utilities for autonomous agents.
我該用這個嗎
品質與安全性
A
根據工具定義與協定合規性的自動化分析。
上下文成本
~1,882Token（工具定義）
~4.3 KB典型回應大小
中等的注意力影響（128k 上下文的 1.47%）
這是每次將伺服器的工具載入模型上下文時所消耗的約略 token 數量。數量越高，可用於其他工作的注意力就越少。
安裝
一鍵安裝
將以下內容加入你的 `claude_desktop_config.json` 檔案：
{
"mcpServers": {
"fallback-agent-tools": {
"url": "https://fallback.factrail.online/mcp"
}
}
}遠端端點
https://fallback.factrail.online/mcpstreamable-http它能做什麼
工具清單
工具（4）
🟢 唯讀🟡 寫入🔴 刪除⚪ 未知
🟢source_route(goal, domain, start_url, preferred_formats, require_official, ...)
Find likely authoritative or machine-readable sources when you know what information you need but not where to retrieve it. Provide a goal and optional publisher domain or start URL; it returns ranked candidate routes and bounded evidence. Use it before blind searching. Do not use it when you already have the correct source or only need reasoning over supplied context. Price: $0.02 USD per call via x402.
輸入結構描述
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 3,
"maxLength": 500
},
"domain": {
"type": "string",
"maxLength": 253,
"format": "hostname",
"pattern": "^(?=.{1,253}\\.?$)[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[-0-9a-zA-Z]{0,61}[0-9a-zA-Z])?)*\\.?$"
},
"start_url": {
"type": "string",
"maxLength": 2048
},
"preferred_formats": {
"maxItems": 7,
"type": "array",
"items": {
"type": "string",
"enum": [
"json",
"csv",
"xml",
"rss",
"api",
"bulk_download",
"html"
]
}
},
"require_official": {
"default": false,
"type": "boolean"
},
"max_candidates": {
"default": 5,
"type": "integer",
"minimum": 1,
"maximum": 10
}
},
"required": [
"goal"
],
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false
}⚪error_route(goal, request, response, error, attempt)
Diagnose a failed API, HTTP, MCP, or tool request and return a bounded safe next action. Use it after a request fails when the safe next step is unclear. Provide a status, response, or error text; it does not execute requests or verify undocumented fixes. Price: $0.002 USD per call via x402.
輸入結構描述
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 500
},
"request": {
"type": "object",
"properties": {
"method": {
"type": "string",
"maxLength": 16
},
"url": {
"type": "string",
"maxLength": 2048
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 2048
}
},
"body": {}
},
"additionalProperties": false
},
"response": {
"type": "object",
"properties": {
"status": {
"type": "integer",
"minimum": 100,
"maximum": 599
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 2048
}
},
"body": {
"type": "string",
"maxLength": 8192
}
},
"additionalProperties": false
},
"error": {
"type": "string",
"maxLength": 2048
},
"attempt": {
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false
}⚪request_repair(goal, request, response, error, error_route, ...)
Repair a failed API or HTTP request using only supplied schema and error evidence. Use after error_route identifies a request-shape or input problem. Returns the smallest justified request changes and abstains when evidence is insufficient. Price: $0.005 USD per call via x402.
輸入結構描述
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 500
},
"request": {
"type": "object",
"properties": {
"method": {
"type": "string",
"minLength": 1,
"maxLength": 16
},
"url": {
"type": "string",
"maxLength": 2048
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 4096
}
},
"query": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"$ref": "#/$defs/__schema0"
}
},
"body": {
"$ref": "#/$defs/__schema0"
}
},
"additionalProperties": false
},
"response": {
"type": "object",
"properties": {
"status": {
"type": "integer",
"minimum": 100,
"maximum": 599
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 4096
}
},
"body": {
"$ref": "#/$defs/__schema0"
}
},
"additionalProperties": false
},
"error": {
"type": "string",
"maxLength": 4000
},
"error_route": {
"type": "object",
"properties": {
"classification": {
"type": "string",
"enum": [
"authentication_required",
"authorization_denied",
"rate_limited",
"quota_exhausted",
"payment_required",
"payment_failed",
"schema_mismatch",
"invalid_input",
"not_found",
"method_not_allowed",
"unsupported_media_type",
"timeout",
"connection_failure",
"dns_failure",
"tls_failure",
"upstream_failure",
"service_unavailable",
"conflict",
"stale_state",
"malformed_response",
"blocked_or_challenged",
"unknown"
]
},
"retry": {
"type": "string",
"enum": [
"never",
"immediate",
"after_delay",
"after_change",
"after_auth",
"after_payment",
"unknown"
]
}
},
"required": [
"classification"
],
"additionalProperties": {}
},
"schema": {
"$ref": "#/$defs/__schema0"
},
"constraints": {
"default": {
"allow_method_change": false,
"allow_url_change": false
},
"type": "object",
"properties": {
"allow_method_change": {
"default": false,
"type": "boolean"
},
"allow_url_change": {
"default": false,
"type": "boolean"
}
},
"additionalProperties": false
}
},
"required": [
"request"
],
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"$defs": {
"__schema0": {
"anyOf": [
{
"type": "string",
"maxLength": 8192
},
{
"type": "number"
},
{
"type": "boolean"
},
{
"type": "null"
},
{
"maxItems": 256,
"type": "array",
"items": {
"$ref": "#/$defs/__schema0"
}
},
{
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"$ref": "#/$defs/__schema0"
}
}
]
}
}
}🟢stop_search(goal, checks, remaining_routes, search_budget, risk)
Decide whether another search or paid retrieval is worth the cost based on the scope already checked. Use after several search or source checks when you need to decide whether to continue or return a scoped not-found result. It does not prove universal absence and performs no searches itself. Price: $0.003 USD per call via x402.
輸入結構描述
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 500
},
"checks": {
"default": [],
"maxItems": 40,
"type": "array",
"items": {
"type": "object",
"properties": {
"target": {
"type": "string",
"minLength": 1,
"maxLength": 300
},
"method": {
"type": "string",
"enum": [
"direct",
"search",
"documentation",
"api_catalog",
"registry",
"browser",
"other"
]
},
"result": {
"type": "string",
"enum": [
"found",
"not_found",
"inconclusive",
"error",
"blocked",
"contradictory"
]
},
"authority": {
"type": "string",
"enum": [
"primary",
"official",
"secondary",
"general",
"unknown"
]
},
"coverage": {
"type": "string",
"enum": [
"low",
"medium",
"high"
]
},
"exhaustive": {
"default": false,
"type": "boolean"
},
"checked_at": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
}
},
"required": [
"target",
"method",
"result",
"authority",
"coverage"
],
"additionalProperties": false
}
},
"remaining_routes": {
"default": [],
"maxItems": 20,
"type": "array",
"items": {
"type": "object",
"properties": {
"route": {
"type": "string",
"minLength": 1,
"maxLength": 300
},
"expected_value": {
"anyOf": [
{
"type": "string",
"enum": [
"low",
"medium",
"high"
]
},
{
"type": "string",
"const": "unknown"
}
]
},
"estimated_cost_usd": {
"type": "number",
"minimum": 0,
"maximum": 10000
}
},
"required": [
"route",
"expected_value"
],
"additionalProperties": false
}
},
"search_budget": {
"type": "object",
"properties": {
"calls_used": {
"type": "integer",
"minimum": 0,
"maximum": 10000
},
"calls_remaining": {
"type": "integer",
"minimum": 0,
"maximum": 10000
},
"cost_used_usd": {
"type": "number",
"minimum": 0,
"maximum": 10000
},
"cost_remaining_usd": {
"type": "number",
"minimum": 0,
"maximum": 10000
}
},
"additionalProperties": false
},
"risk": {
"default": "medium",
"type": "string",
"enum": [
"low",
"medium",
"high"
]
}
},
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false
}社群
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