HTTP 的 RateLimit 头字段

Roberto Polli Team Digitale，意大利政府 意大利 邮箱： robipolli@gmail.com

   RateLimit-Policy: "burst";q=100;w=60,"daily";q=1000;w=86400

   RateLimit-Policy: "default";q=100;w=10

   RateLimit-Policy: "permin";q=50;w=60,"perhr";q=1000;w=3600

   RateLimit-Policy: "peruser";q=100;w=60;pk=:cHsdsRa894==:

   RateLimit-Policy: "peruser";q=65535;qu="content-bytes";w=10;pk=:sdfjLJUOUH==:

   RateLimit: "default";r=50;t=30

   RateLimit: "default";r=50;t=30

   RateLimit: "default";r=999;pk=:dHJpYWwxMjEzMjM=:

   RateLimit: "default";r=300000000;t=60;pk=:QXBwLTk5OQ==:

HTTP/1.1 429 Bad Request
Content-Type: application/problem+json

{
  "type": "https://iana.org/assignments/http-problem-types#quota-exceeded",
  "title": "Request cannot be satisfied as assigned quota has been exceeded",
  "violated-policies": ["daily","bandwidth"]
}

HTTP/1.1 503 Server Unavailable
Content-Type: application/problem+json

{
  "type": "https://iana.org/assignments/http-problem-types#temporary-reduced-capacity",
  "title": "Request cannot be satisfied due to temporary server capacity constraints",
  "violated-policies": ["hourly"]
}

HTTP/1.1 429 Too Many Requests
Content-Type: application/problem+json

{
  "type": "https://iana.org/assignments/http-problem-types#abnormal-usage-detected",
  "title": "Request not satisifed due to detection of abnormal request pattern",
  "violated-policies": ["hourly"]
}

HTTP/1.1 301 Moved Permanently
Location: /foo/123
RateLimit: "problemPolicy";r=0;t=10


   RateLimit: "default";r=1;t=7

   Date: Tue, 15 Nov 1994 18:00:00 GMT
   RateLimit: "daily";r=1;t=86400

RateLimit-Policy: "somepolicy";q=10000;w=1000
RateLimit: "somepolicy";r=10000;t=10

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit: "default";r=0;t=50

{"hello": "world"}

GET /items/456 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit: "default";r=0;t=48

{"still": "successful"}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit: "dayLimit";r=100;t=36000

{"hello": "world"}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit-Policy: "basic";q=100;w=60
RateLimit: "basic";r=60;t=58

{"elapsed": 2, "issued": 40}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit-Policy: "basic";q=100;w=60
RateLimit: "basic";r=20;t=56

{"elapsed": 4, "issued": 41}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 429 Too Many Requests
Content-Type: application/problem+json
Date: Mon, 05 Aug 2019 09:27:00 GMT
Retry-After: Mon, 05 Aug 2019 09:27:05 GMT
RateLimit: "default";r=0;t=5

{
"type": "https://iana.org/assignments/http-problem-types#quota-exceeded"
"title": "Too Many Requests",
"status": 429,
"violated-policies": ["default"]
}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit: "fixedwindow";r=99;t=50
RateLimit-Policy: "fixedwindow";q=100;w=60
{"hello": "world"}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 Ok
Content-Type: application/json
RateLimit-Policy: "dynamic";q=100;w=60
RateLimit: "dynamic";r=9;t=50


{
  "status": 200,
  "detail": "Just slow down without waiting."
}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 429 Too Many Requests
Content-Type: application/json
RateLimit-Policy: "dynamic";q=15;w=20
RateLimit: "dynamic";r=0;t=20

{
  "status": 429,
  "detail": "Wait 20 seconds, then slow down!"
}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 429 Too Many Requests
Content-Type: application/json
Retry-After: 20
RateLimit-Policy: "dynamic";q=100;w=60
RateLimit: "dynamic";r=15;t=40

{
  "status": 429,
  "detail": "Wait 20 seconds, then slow down!"
}

GET /items/123 HTTP/1.1
Host: api.example


HTTP/1.1 200 OK
Content-Type: application/json
RateLimit-Policy: "hour";q=1000;w=3600, "day";q=5000;w=86400
RateLimit: "day";r=100;t=36000

{"hello": "world"}

RateLimit:"default";r=50;t=60

RateLimit-Policy: "sliding";q=100;w=60;burst=1000
RateLimit-Policy: "fixed";q=5000;w=3600;burst=0
RateLimit: "sliding";r=50;t=44

RateLimit-Policy: "sliding";q=12;w=1
; using 50% of throughput, that is 6 units/s
RateLimit: "sliding";q=12;r=6;t=1


RateLimit-Policy: "sliding";q=12;w=1
; using 100% of throughput, that is 12 units/s
RateLimit: "sliding";q=12;r=1;t=1

互联网草案	HTTP 的 RateLimit 头字段	2026 年 5 月
Polli 等	2026 年 11 月 24 日到期	[页]

字段名	结构化类型	状态	规范
RateLimit	List	永久	RFC nnnn 的第 4 节
RateLimit-Policy	List	永久	RFC nnnn 的第 3 节

配额单位	引用	说明
request	RFC nnnn
content-bytes	RFC nnnn
concurrent-requests	RFC nnnn