Migrates the AMP module to a new unified routing system, replacing the fallback handler with a router-based approach.
This change introduces a `ModelRoutingWrapper` that handles model extraction, routing decisions, and proxying based on provider availability and model mappings.
It provides a more flexible and maintainable routing mechanism by centralizing routing logic.
The changes include:
- Introducing new `routing` package with core routing logic.
- Creating characterization tests to capture existing behavior.
- Implementing model extraction and rewriting.
- Updating AMP module routes to utilize the new routing wrapper.
- Deprecating `FallbackHandler` in favor of the new `ModelRoutingWrapper`.
Improves AMP request handling by consolidating model mapping logic into a helper function for better readability and maintainability.
Enhances error handling for premature client connection closures during reverse proxy operations by explicitly acknowledging and swallowing the ErrAbortHandler panic, preventing noisy stack traces.
Removes unused method `findProviderViaOAuthAlias` from the `DefaultModelMapper`.
Uses centralized context keys for accessing mapped and fallback models.
This change deprecates the string-based context keys used in the AMP fallback handlers in favor of the `ctxkeys` package, promoting consistency and reducing the risk of typos.
The authentication conductor now retrieves fallback models using the shared `ctxkeys` constants.
- Added a new routing package to manage provider registration and model resolution.
- Introduced Router, Executor, and Provider interfaces to handle different provider types.
- Implemented OAuthProvider and APIKeyProvider to support OAuth and API key authentication.
- Enhanced DefaultModelMapper to include OAuth model alias handling and fallback mechanisms.
- Updated context management in API handlers to preserve fallback models.
- Added tests for routing logic and provider selection.
- Enhanced Claude request conversion to handle reasoning content based on thinking mode.
Enhances the AMP model mapping functionality to support fallback mechanisms using .
This change allows the system to attempt alternative models (aliases) if the primary mapped model fails due to issues like quota exhaustion. It updates the model mapper to load and utilize the configuration, enabling provider lookup via aliases. It also introduces context keys to pass fallback model names between handlers.
Additionally, this change introduces a fix to prevent ReverseProxy from panicking by swallowing ErrAbortHandler panics.
Amp-Thread-ID: https://ampcode.com/threads/T-019c0cd1-9e59-722b-83f0-e0582aba6914
Co-authored-by: Amp <amp@ampcode.com>
This commit introduces several improvements to the AMP (Advanced Model Proxy) module:
- **Model Mapping Logic:** The `FallbackHandler` now uses a more robust approach for model mapping. It includes the extraction and preservation of dynamic "thinking suffixes" (e.g., `(xhigh)`) during mapping, ensuring that these configurations are correctly applied to the mapped model. A new `resolveMappedModel` function centralizes this logic for cleaner code.
- **ModelMapper Verification:** The `ModelMapper` in `model_mapping.go` now verifies that the target model of a mapping has available providers *after* normalizing it. This prevents mappings to non-existent or unresolvable models.
- **Gemini Thinking Configuration Cleanup:** In `gemini_thinking.go`, unnecessary `generationConfig.thinkingConfig.include_thoughts` and `generationConfig.thinkingConfig.thinkingBudget` fields are now deleted from the request body when applying Gemini thinking levels. This prevents potential conflicts or redundant configurations.
- **Testing:** A new test case `TestModelMapper_MapModel_TargetWithThinkingSuffix` has been added to `model_mapping_test.go` to specifically cover the preservation of thinking suffixes during model mapping.
Ensures compatibility with the Amp client by suppressing
"thinking" blocks when "tool_use" blocks are also present in
the response.
The Amp client has issues rendering both types of blocks
simultaneously. This change filters out "thinking" blocks in
such cases, preventing rendering problems.
Normalize action handling by accommodating wildcard patterns in route definitions for Gemini endpoints. Adjust `request.Action` parsing logic to correctly process routes with prefixed actions.
All Amp management endpoints (e.g., /api/user, /threads) are now protected by the standard API key authentication middleware. This ensures that all management operations require a valid API key, significantly improving security.
As a result of this change:
- The `restrict-management-to-localhost` setting now defaults to `false`. API key authentication provides a stronger and more flexible security control than IP-based restrictions, improving usability in containerized environments.
- The reverse proxy logic now strips the client's `Authorization` header after authenticating the initial request. It then injects the configured `upstream-api-key` for the request to the upstream Amp service.
BREAKING CHANGE: Amp management endpoints now require a valid API key for authentication. Requests without a valid API key in the `Authorization` header will be rejected with a 401 Unauthorized error.
- Added support for parsing and normalizing dynamic thinking model suffixes.
- Centralized budget resolution across executors and payload helpers.
- Retired legacy Gemini-specific thinking handlers in favor of unified logic.
- Updated executors to use metadata-based thinking configuration.
- Added `ResolveOriginalModel` utility for resolving normalized upstream models using request metadata.
- Updated executors (Gemini, Codex, iFlow, OpenAI, Qwen) to incorporate upstream model resolution and substitute model values in payloads and request URLs.
- Ensured fallbacks handle cases with missing or malformed metadata to derive models robustly.
- Refactored upstream model resolution to dynamically incorporate metadata for selecting and normalizing models.
- Improved handling of thinking configurations and model overrides in executors.
- Removed hardcoded thinking model entries and migrated logic to metadata-based resolution.
- Updated payload mutations to always include the resolved model.
Add a configuration option to control whether model mappings take
precedence over local API keys for Amp CLI requests.
- Add PrioritizeModelMappings field to AmpCode config struct
- When false (default): Local API keys take precedence (original behavior)
- When true: Model mappings take precedence over local API keys
- Add management API endpoints GET/PUT /prioritize-model-mappings
This allows users who want mapping priority to enable it explicitly
while preserving backward compatibility.
Config example:
ampcode:
model-mappings:
- from: claude-opus-4-5-20251101
to: gemini-claude-opus-4-5-thinking
prioritize-model-mappings: true
Simplifies routing logic by delegating all provider/mapping/proxy
decisions to FallbackHandler. Previously, the route checked for
provider/mapping availability before calling the handler, then
FallbackHandler performed the same checks again.
Changes:
- Remove model extraction and provider checking from route (lines 182-201)
- Route now only checks if request is POST with /models/ path
- FallbackHandler handles provider -> mapping -> proxy fallback
- Remove unused internal/util import
Benefits:
- Eliminates duplicate checks (addresses PR review feedback #2)
- Centralizes all provider/mapping logic in FallbackHandler
- Reduces routing code by ~20 lines
- Aligns with how other /api/provider routes work
Performance: No impact (checks still happen once in FallbackHandler)
- Change createGeminiBridgeHandler to accept gin.HandlerFunc instead of *gemini.GeminiAPIHandler
This allows tests to inject mock handlers instead of duplicating bridge logic
- Replace magic number 8 with len(modelsPrefix) for better maintainability
- Remove redundant test case that doesn't test edge case in production
- Update routes.go to pass geminiHandlers.GeminiHandler directly
Addresses PR review feedback on test architecture and code clarity.
Amp-Thread-ID: https://ampcode.com/threads/T-1ae2c691-e434-4b99-a49a-10cabd3544db
Gemini handler extracts model from URL path, not JSON body, so
rewriting the request body alone wasn't sufficient for model mapping.
- Add MappedModelContextKey constant for context passing
- Update routes.go to use NewFallbackHandlerWithMapper
- Add check for valid mapping before routing to local handler
- Add tests for gemini bridge model mapping
- Store ampModule in Server struct to access it during config updates
- Call ampModule.OnConfigUpdated() in UpdateClients() for hot reload
- Watch config directory instead of file to handle atomic saves (vim, VSCode, etc.)
- Improve config file event detection with basename matching
- Add diagnostic logging for config reload tracing
AMP CLI requests /threads.rss at the root level, but the AMP module
only registered routes under /api/*. This caused a 404 error during
AMP CLI startup.
Add the missing root-level route with the same security middleware
(noCORS, optional localhost restriction) as other management routes.
- Add AmpModelMapping config to route models like 'claude-opus-4.5' to 'claude-sonnet-4'
- Add ModelMapper interface and DefaultModelMapper implementation with hot-reload support
- Enhance FallbackHandler to apply model mappings before falling back to ampcode.com
- Add structured logging for routing decisions (local provider, mapping, amp credits)
- Update config.example.yaml with amp-model-mappings documentation
