Fallback
Tiny paid recovery and decision utilities for autonomous agents.
我该使用它吗
质量与安全性
A
基于对工具定义和协议合规性的自动分析。
上下文开销
~1,882token 数（工具定义）
~4.3 KB典型响应大小
对注意力有中等影响（占 128k 上下文窗口的 1.47%）
这是每次将服务器的工具加载到模型上下文窗口时所消耗的大致 token 数。数值越高，可用于其他任务的注意力就越少。
安装
一键安装
将以下内容添加到你的 `claude_desktop_config.json` 文件中：
{
"mcpServers": {
"fallback-agent-tools": {
"url": "https://fallback.factrail.online/mcp"
}
}
}远程端点
https://fallback.factrail.online/mcpstreamable-http它能做什么
工具清单
工具（4）
🟢 只读🟡 写入🔴 删除⚪ 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: $0.02 USD per call via x402.
输入模式
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 3,
"maxLength": 500
},
"domain": {
"type": "string",
"maxLength": 253,
"format": "hostname",
"pattern": "^(?=.{1,253}\\.?$)[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: $0.002 USD per call via x402.
输入模式
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 500
},
"request": {
"type": "object",
"properties": {
"method": {
"type": "string",
"maxLength": 16
},
"url": {
"type": "string",
"maxLength": 2048
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 2048
}
},
"body": {}
},
"additionalProperties": false
},
"response": {
"type": "object",
"properties": {
"status": {
"type": "integer",
"minimum": 100,
"maximum": 599
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 2048
}
},
"body": {
"type": "string",
"maxLength": 8192
}
},
"additionalProperties": false
},
"error": {
"type": "string",
"maxLength": 2048
},
"attempt": {
"type": "integer",
"minimum": 1,
"maximum": 100
}
},
"$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: $0.005 USD per call via x402.
输入模式
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 500
},
"request": {
"type": "object",
"properties": {
"method": {
"type": "string",
"minLength": 1,
"maxLength": 16
},
"url": {
"type": "string",
"maxLength": 2048
},
"headers": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"type": "string",
"maxLength": 4096
}
},
"query": {
"type": "object",
"propertyNames": {
"type": "string",
"maxLength": 128
},
"additionalProperties": {
"$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: $0.003 USD per call via x402.
输入模式
{
"type": "object",
"properties": {
"goal": {
"type": "string",
"minLength": 1,
"maxLength": 500
},
"checks": {
"default": [],
"maxItems": 40,
"type": "array",
"items": {
"type": "object",
"properties": {
"target": {
"type": "string",
"minLength": 1,
"maxLength": 300
},
"method": {
"type": "string",
"enum": [
"direct",
"search",
"documentation",
"api_catalog",
"registry",
"browser",
"other"
]
},
"result": {
"type": "string",
"enum": [
"found",
"not_found",
"inconclusive",
"error",
"blocked",
"contradictory"
]
},
"authority": {
"type": "string",
"enum": [
"primary",
"official",
"secondary",
"general",
"unknown"
]
},
"coverage": {
"type": "string",
"enum": [
"low",
"medium",
"high"
]
},
"exhaustive": {
"default": false,
"type": "boolean"
},
"checked_at": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"
}
},
"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
}社区
证据
最近观测
已验证未记录版本4 个工具