Documentation
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Overview ¶
Package middleware provides HTTP middleware chain for request and response processing.
This package re-exports the public API from internal/common/middleware, providing external consumers with a flexible middleware infrastructure for AI provider requests and responses.
Overview ¶
The middleware package enables request transformation, response processing, logging, metrics collection, and other cross-cutting concerns through a composable middleware chain pattern. Middleware can process requests before they are sent to AI providers and responses after they are received.
Key Components ¶
- RequestMiddleware: Processes HTTP requests before sending
- ResponseMiddleware: Processes HTTP responses after receiving
- Middleware: Combined interface for both request and response processing
- MiddlewareChain: Manages ordered middleware execution
Basic Usage ¶
// Create a new middleware chain
chain := middleware.NewMiddlewareChain()
// Add middleware to the chain
chain.Add(loggingMiddleware).
Add(metricsMiddleware).
Add(retryMiddleware)
// Process a request
ctx := context.Background()
req, _ := http.NewRequest("POST", "https://api.openai.com/v1/chat/completions", body)
newCtx, newReq, err := chain.ProcessRequest(ctx, req)
if err != nil {
// Handle error
}
// Make the HTTP call
resp, err := client.Do(newReq)
if err != nil {
// Handle error
}
// Process the response
newCtx, newResp, err := chain.ProcessResponse(newCtx, newReq, resp)
Context Keys ¶
The package provides standard context keys for passing data between middleware:
ContextKeyRequestID: Unique request identifier
ContextKeyStartTime: Request start time
ContextKeyProvider: Provider name (e.g., "openai", "anthropic")
ContextKeyModel: Model name (e.g., "gpt-4", "claude-3")
ContextKeyMetadata: Arbitrary metadata map
ContextKeyError: Error information
ContextKeyRetryCount: Retry attempt count
// Store data in context ctx = context.WithValue(ctx, middleware.ContextKeyProvider, "openai") ctx = context.WithValue(ctx, middleware.ContextKeyModel, "gpt-4") ctx = context.WithValue(ctx, middleware.ContextKeyRetryCount, 0)
// Retrieve data from context if provider, ok := ctx.Value(middleware.ContextKeyProvider).(string); ok { // Use provider }
Execution Order ¶
The middleware chain executes in a specific order:
- Request middleware: Execute in the order they were added (first to last)
- Response middleware: Execute in reverse order (last to first)
This ensures symmetric processing, similar to nested function calls:
Request: MW1 -> MW2 -> MW3 -> [HTTP Call] Response: MW1 <- MW2 <- MW3 <- [HTTP Call]
Index ¶
- func NewCombinedMiddleware(reqProcessor middleware.RequestMiddleware, ...) *middleware.CombinedMiddleware
- func NewMiddlewareChain() *middleware.DefaultMiddlewareChain
- type CombinedMiddleware
- type ContextKey
- type DefaultMiddlewareChain
- type Middleware
- type MiddlewareChain
- type RequestMiddleware
- type RequestMiddlewareFunc
- type ResponseMiddleware
- type ResponseMiddlewareFunc
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func NewCombinedMiddleware ¶
func NewCombinedMiddleware(reqProcessor middleware.RequestMiddleware, respProcessor middleware.ResponseMiddleware) *middleware.CombinedMiddleware
NewCombinedMiddleware creates a new combined middleware. Use this to combine separate request and response processors into a single middleware.
func NewMiddlewareChain ¶
func NewMiddlewareChain() *middleware.DefaultMiddlewareChain
NewMiddlewareChain creates a new middleware chain. The returned chain is empty and ready to have middleware added.
Types ¶
type CombinedMiddleware ¶
type CombinedMiddleware = middleware.CombinedMiddleware
CombinedMiddleware is a middleware that implements both RequestMiddleware and ResponseMiddleware.
type ContextKey ¶
type ContextKey = middleware.ContextKey
ContextKey is the type used for middleware context keys.
const ( // ContextKeyRequestID stores a unique request identifier. ContextKeyRequestID ContextKey = middleware.ContextKeyRequestID // ContextKeyStartTime stores the request start time. ContextKeyStartTime ContextKey = middleware.ContextKeyStartTime // ContextKeyProvider stores the provider name. ContextKeyProvider ContextKey = middleware.ContextKeyProvider // ContextKeyModel stores the model name. ContextKeyModel ContextKey = middleware.ContextKeyModel // ContextKeyMetadata stores arbitrary metadata. ContextKeyMetadata ContextKey = middleware.ContextKeyMetadata // ContextKeyError stores error information. ContextKeyError ContextKey = middleware.ContextKeyError // ContextKeyRetryCount stores the retry attempt count. ContextKeyRetryCount ContextKey = middleware.ContextKeyRetryCount )
Standard context keys for passing data between middleware.
type DefaultMiddlewareChain ¶
type DefaultMiddlewareChain = middleware.DefaultMiddlewareChain
DefaultMiddlewareChain is the default implementation of MiddlewareChain. It is thread-safe and can be used concurrently.
type Middleware ¶
type Middleware = middleware.Middleware
Middleware is a combined interface for both request and response processing. Middleware implementations can implement either or both interfaces.
type MiddlewareChain ¶
type MiddlewareChain = middleware.MiddlewareChain
MiddlewareChain manages an ordered collection of middleware. Provides methods to add, remove, and execute middleware in the chain.
type RequestMiddleware ¶
type RequestMiddleware = middleware.RequestMiddleware
RequestMiddleware transforms requests before they are sent to the provider. Implement ProcessRequest to modify the request, context, or return an error to abort.
type RequestMiddlewareFunc ¶
type RequestMiddlewareFunc = middleware.RequestMiddlewareFunc
RequestMiddlewareFunc is a function adapter for RequestMiddleware. Allows simple functions to be used as request middleware.
type ResponseMiddleware ¶
type ResponseMiddleware = middleware.ResponseMiddleware
ResponseMiddleware transforms responses after they are received from the provider. Implement ProcessResponse to modify the response, context, or return an error.
type ResponseMiddlewareFunc ¶
type ResponseMiddlewareFunc = middleware.ResponseMiddlewareFunc
ResponseMiddlewareFunc is a function adapter for ResponseMiddleware. Allows simple functions to be used as response middleware.
Source Files