AI Rate Limiting Configuration

Parameters

See plugin common configurations for configuration options available to all plugins.

In API7 Enterprise (from 3.8.17) and in APISIX (from 3.16.0), you should configure one of the following parameter sets, but not both:

rules
Any combination of limit and time_window and/or instances

limit — integer | string · optional

Valid values: greater than 0

The maximum number of tokens allowed to consume within a given time interval.

In API7 Enterprise (from 3.8.17) and in APISIX (from 3.16.0), this parameter also supports the string data type and allows the use of built-in variables prefixed with a dollar sign ($). In earlier APISIX versions, only the integer type is supported.
time_window — integer | string · optional

Valid values: greater than 0

The time interval corresponding to the rate limiting limit in seconds.

In API7 Enterprise (from 3.8.17) and in APISIX (from 3.16.0), this parameter also supports the string data type and allows the use of built-in variables prefixed with a dollar sign ($). In earlier APISIX versions, only the integer type is supported.
show_limit_quota_header — boolean · optional · default: true

If true, includes the rate limiting response headers. Specifically, when using limit/time_window or instances, the headers include the instance name as a suffix:
- X-AI-RateLimit-Limit-{name} shows the total quota.
- X-AI-RateLimit-Remaining-{name} shows the remaining quota.
- X-AI-RateLimit-Reset-{name} shows the number of seconds until the counter resets.
When rules is set, the headers use a prefix instead. See rules.header_prefix for details.
limit_strategy — string · optional · default: total_tokens

Valid values: total_tokens, prompt_tokens, completion_tokens, or expression

Type of token to apply rate limiting. total_tokens, prompt_tokens, and completion_tokens values are returned in each model response, where total_tokens is the sum of prompt_tokens and completion_tokens.

When set to expression, rate limiting cost is calculated using a custom Lua arithmetic expression defined in cost_expr. Available in API7 Enterprise from version 3.9.8 and APISIX from version 3.17.0.
cost_expr — string · optional

Valid values: any non-empty string (must be a valid Lua arithmetic expression)

Lua arithmetic expression for dynamic token cost calculation. Variables are injected from the LLM provider's raw usage response fields (e.g., input_tokens, output_tokens, cache_creation_input_tokens). Missing variables default to 0. Only math functions (abs, ceil, floor, max, min) and arithmetic operators are allowed. Expression syntax is validated when limit_strategy is expression, where this field is required.

Example: input_tokens + cache_creation_input_tokens computes cost from Anthropic Claude's cache-aware token usage.

Available in API7 Enterprise from version 3.9.8 and APISIX from version 3.17.0.
instances — array[object] · optional

LLM instance rate limiting configurations.
- name — string · required
  
  Name of the LLM service instance.
- limit — integer | string · required
  
  Valid values: greater than 0
  
  The maximum number of tokens allowed to consume within a given time interval.
  
  In API7 Enterprise (from 3.8.17) and in APISIX (from 3.16.0), this parameter also supports the string data type and allows the use of built-in variables prefixed with a dollar sign ($). In earlier APISIX versions, only the integer type is supported.
- time_window — integer | string · required
  
  Valid values: greater than 0
  
  The time interval corresponding to the rate limiting limit in seconds.
  
  In API7 Enterprise (from 3.8.17) and in APISIX (from 3.16.0), this parameter also supports the string data type and allows the use of built-in variables prefixed with a dollar sign ($). In earlier APISIX versions, only the integer type is supported.
rejected_code — integer · optional · default: 503

Valid values: between 200 and 599 inclusive

The HTTP status code returned when a request exceeding the quota is rejected.
rejected_msg — string · optional

Valid values: any non-empty string

The response body returned when a request exceeding the quota is rejected.
policy — string · optional · default: local

Valid values: local, redis, redis-cluster, or redis-sentinel

The policy for rate limiting counters. API7 Gateway requires this field; use local for configurations that do not use Redis. APISIX uses local when the field is omitted.

Redis-backed policies are available in API7 Enterprise from version 3.8.19 and in APISIX from version 3.18.0.

Set to local to store the counter in memory locally.

Set to redis to store the counter on a Redis instance.

Set to redis-cluster to store the counter in a Redis cluster.

Set to redis-sentinel to store the counter on the Redis primary node managed by Redis Sentinel, which ensures high availability by automatically promoting a replica to primary in case of failure. Redis Sentinel provides high availability for Redis when not using Redis Cluster.
redis_host — string · optional

The address of the Redis node. Required when policy is redis.
redis_port — integer · optional · default: 6379

Valid values: greater than or equal to 1

The port of the Redis node when policy is redis.
redis_username — string · optional

The username for Redis if Redis ACL is used. If you use the legacy authentication method requirepass, configure only redis_password. Used when policy is redis, and with redis-sentinel in API7 Enterprise 3.10.5 and APISIX 3.18.0.
redis_password — string · optional

Password of the Redis node when policy is redis or redis-cluster, and with redis-sentinel in API7 Enterprise 3.10.5 and APISIX 3.18.0.

In API7 Gateway 3.10.2 or later in the 3.10 release series, and 3.9.16 or later in the 3.9 release series, the value is encrypted with AES256 before being saved to the database.

In APISIX 3.18.0 or later, the value is encrypted with AES before being stored in etcd.
redis_database — integer · optional · default: 0

Valid values: greater than or equal to 0

The database number in Redis when policy is redis or redis-sentinel.
redis_ssl — boolean · optional · default: false

If true, use SSL to connect to Redis when policy is redis.
redis_ssl_verify — boolean · optional · default: false

If true, verify the server SSL certificate when policy is redis.
redis_timeout — integer · optional · default: 1000

Valid values: greater than or equal to 1

The Redis timeout value in milliseconds when policy is redis or redis-cluster.
redis_cluster_nodes — array[string] · optional

List of Redis cluster nodes with at least one address. Required when policy is redis-cluster.
redis_cluster_name — string · optional

The name of the Redis cluster. Required when policy is redis-cluster.
redis_cluster_ssl — boolean · optional · default: false

If true, use SSL to connect to Redis cluster when policy is redis-cluster.
redis_cluster_ssl_verify — boolean · optional · default: false

If true, verify the server SSL certificate when policy is redis-cluster.
redis_sentinels — array[object] · optional

An array of Redis Sentinel nodes (host and port). Required when policy is redis-sentinel.
redis_master_name — string · optional

The name of the Redis master group that Sentinels are monitoring. Required when policy is redis-sentinel.
redis_role — string · optional · default: master

Valid values: master or slave

The Redis node role to connect to. Configurable when policy is redis-sentinel. Set to master to connect to the current Redis master, and set to slave to connect to a Redis replica.
redis_connect_timeout — integer · optional · default: 1000

Valid values: greater than or equal to 1

Timeout in milliseconds for establishing a connection to a Redis node. Configurable when policy is redis-sentinel.
redis_read_timeout — integer · optional · default: 1000

Valid values: greater than or equal to 1

Timeout in milliseconds for reading data from a Redis node. Configurable when policy is redis-sentinel.
redis_keepalive_timeout — integer · optional · default: 10000 for redis or redis-cluster; 60000 for redis-sentinel

Valid values: redis and redis-cluster: greater than or equal to 1000; redis-sentinel: greater than or equal to 1

Time in milliseconds that an idle Redis connection is kept alive in the connection pool before being closed. Used by all Redis-backed policies in APISIX 3.18.0. In API7 Enterprise, it is used by redis-sentinel; redis and redis-cluster support it from version 3.9.16 on the 3.9 release series and version 3.10.3 on the 3.10 release series.
redis_keepalive_pool — integer · optional · default: 100

Valid values: greater than or equal to 1

Maximum number of idle Redis connections in the keepalive pool. Used when policy is redis or redis-cluster. Available in API7 Enterprise from version 3.9.16 on the 3.9 release series and version 3.10.3 on the 3.10 release series, and in APISIX from version 3.18.0.
sentinel_username — string · optional

Username used to authenticate with the Redis Sentinel instance. Configurable when policy is redis-sentinel.
sentinel_password — string · optional

Password used to authenticate with the Redis Sentinel instance. Configurable when policy is redis-sentinel.

In API7 Gateway 3.10.2 or later in the 3.10 release series, and 3.9.16 or later in the 3.9 release series, the value is encrypted with AES256 before being saved to the database.

In APISIX 3.18.0 or later, the value is encrypted with AES before being stored in etcd.
allow_degradation — boolean · optional · default: false

If true, allow the gateway to continue handling requests without the plugin when the plugin or its dependencies become unavailable.

Available in API7 Enterprise from version 3.8.19 and in APISIX from version 3.18.0.
rules — array[object] · optional

An array of rate-limiting rules that are applied sequentially.

Available in API7 Enterprise from 3.8.17 and in APISIX from 3.16.0.
- count — integer | string · required
  
  Valid values: greater than 0
  
  The maximum number of tokens allowed to consume within a given time interval.
  
  This parameter also supports the string data type and allows the use of built-in variables prefixed with a dollar sign ($).
- time_window — integer | string · required
  
  Valid values: greater than 0
  
  The time interval corresponding to the rate limiting count in seconds.
  
  This parameter also supports the string data type and allows the use of built-in variables prefixed with a dollar sign ($).
- key — string · required
  
  The key to count requests by. If the configured key does not exist, the rule will not be executed.
  
  The key is interpreted as a variable. The variable does not need to be prefixed by a dollar sign ($). See built-in variables for available variables.
- header_prefix — string · optional
  
  Prefix for all rate limiting response headers. Available in API7 Enterprise from version 3.8.19 and in APISIX from version 3.17.0.
  
  When configured, the prefix is inserted after X-AI- in the header name. For example, with header_prefix set to test, the headers become X-AI-Test-RateLimit-Limit, X-AI-Test-RateLimit-Remaining, and X-AI-Test-RateLimit-Reset.
  
  When not configured, the index of the rule in the rules array is used as the prefix. For example, headers for the first rule will be X-AI-1-RateLimit-Limit, X-AI-1-RateLimit-Remaining, and X-AI-1-RateLimit-Reset.