Custom Providers

What Are Custom Providers?

Custom providers allow you to create multiple instances of the same base provider, each with different configurations and access patterns. The key feature is request type control, which enables you to restrict what operations each custom provider instance can perform. Think of custom providers as “multiple views” of the same underlying provider - you can create several custom configurations for OpenAI, Anthropic, or any other provider, each optimized for different use cases while sharing the same API keys and base infrastructure.

Key Benefits

Multiple Provider Instances: Create several configurations of the same base provider (e.g., multiple OpenAI configurations)
Request Type Control: Restrict which operations (chat, embeddings, speech, etc.) each custom provider can perform
Custom Naming: Use descriptive names like “openai-production” or “openai-staging”
Provider Reuse: Maximize the value of your existing provider accounts

How to Configure

Custom providers are configured using the custom_provider_config field, which extends the standard provider configuration. The main purpose is to create multiple instances of the same base provider, each with different request type restrictions. Important: The allowed_requests field follows a specific behavior:

Omitted entirely: All operations are allowed (default behavior)
Partially specified: Only explicitly set fields are allowed, others default to false
Fully specified: Only the operations you explicitly enable are allowed
Present but empty object ({}): All fields are set to false

Using Web UI
Using API
Using config.json
Go SDK

Go to http://localhost:8080
Navigate to “Providers” in the sidebar
Click “Add New Provider”
Choose a unique provider name (e.g., “openai-custom”)
Select the base provider type (e.g., “openai”)
Configure which request types are allowed
Save configuration

# Create a chat-only custom provider
curl --location 'http://localhost:8080/api/providers' \
--header 'Content-Type: application/json' \
--data '{
    "provider": "openai-custom",
    "keys": [
        {
            "name": "openai-custom-key-1",
            "value": "env.OPENAI_API_KEY",
            "models": ["*"],
            "weight": 1.0
        }
    ],
    "custom_provider_config": {
        "base_provider_type": "openai",
        "allowed_requests": {
            "list_models": false,
            "text_completion": false,
            "text_completion_stream": false,
            "chat_completion": true,
            "chat_completion_stream": true,
            "responses": false,
            "responses_stream": false,
            "embedding": false,
            "speech": false,
            "speech_stream": false,
            "transcription": false,
            "transcription_stream": false
        },
        "request_path_overrides": {
            "chat_completion": "/v1/chat/completions"
        }
    }
}'

{
    "providers": {
        "openai-custom": {
            "keys": [
                {
                    "name": "openai-custom-key-1",
                    "value": "env.OPENAI_API_KEY",
                    "models": ["*"],
                    "weight": 1.0
                }
            ],
            "custom_provider_config": {
                "base_provider_type": "openai",
                "allowed_requests": {
                    "list_models": false,
                    "text_completion": false,
                    "text_completion_stream": false,
                    "chat_completion": true,
                    "chat_completion_stream": true,
                    "responses": false,
                    "responses_stream": false,
                    "embedding": false,
                    "speech": false,
                    "speech_stream": false,
                    "transcription": false,
                    "transcription_stream": false
                },
                "request_path_overrides": {
                    "chat_completion": "/v1/chat/completions"
                }
            }
        }
    }
}

Create a custom provider using the Go SDK by implementing the Account interface with custom provider configuration:

package main

import (
    "context"
    "fmt"
    "os"
    "time"

    "github.com/maximhq/bifrost/core/schemas"
)

// Define custom provider name
const ProviderOpenAICustom = schemas.ModelProvider("openai-custom")

type MyAccount struct{}

func (a *MyAccount) GetConfiguredProviders() ([]schemas.ModelProvider, error) {
    return []schemas.ModelProvider{
        schemas.OpenAI,
        ProviderOpenAICustom, // Include your custom provider
    }, nil
}

func (a *MyAccount) GetKeysForProvider(ctx context.Context, provider schemas.ModelProvider) ([]schemas.Key, error) {
    switch provider {
    case schemas.OpenAI:
        return []schemas.Key{{
            Value:  os.Getenv("OPENAI_API_KEY"),
            Models: []string{},
            Weight: 1.0,
        }}, nil
    case ProviderOpenAICustom:
        return []schemas.Key{{
            Value:  os.Getenv("OPENAI_CUSTOM_API_KEY"), // API key for OpenAI-compatible endpoint
            Models: []string{},
            Weight: 1.0,
        }}, nil
    }
    return nil, fmt.Errorf("provider %s not supported", provider)
}

func (a *MyAccount) GetConfigForProvider(provider schemas.ModelProvider) (*schemas.ProviderConfig, error) {
    switch provider {
    case schemas.OpenAI:
        return &schemas.ProviderConfig{
            NetworkConfig:            schemas.DefaultNetworkConfig,
            ConcurrencyAndBufferSize: schemas.DefaultConcurrencyAndBufferSize,
        }, nil
    case ProviderOpenAICustom:
        return &schemas.ProviderConfig{
            NetworkConfig: schemas.NetworkConfig{
                BaseURL:                        "https://your-openai-compatible-endpoint.com", // Custom base URL
                DefaultRequestTimeoutInSeconds: 60,
                MaxRetries:                     1,
                RetryBackoffInitial:            100 * time.Millisecond,
                RetryBackoffMax:                2 * time.Second,
            },
            ConcurrencyAndBufferSize: schemas.ConcurrencyAndBufferSize{
                Concurrency: 3,
                BufferSize:  10,
            },
            CustomProviderConfig: &schemas.CustomProviderConfig{
                BaseProviderType: schemas.OpenAI, // Use OpenAI protocol
                AllowedRequests: &schemas.AllowedRequests{
                    TextCompletion:       false,
                    TextCompletionStream: false,
                    ChatCompletion:       true,  // Enable chat completion
                    ChatCompletionStream: true,  // Enable streaming
                    Responses:            false,
                    ResponsesStream:      false,
                    Embedding:            false,
                    Speech:               false,
                    SpeechStream:         false,
                    Transcription:        false,
                    TranscriptionStream:  false,
                },
                RequestPathOverrides: map[schemas.RequestType]string{
                    schemas.ChatCompletionRequest:       "/v1/chat/completions",
                    schemas.ChatCompletionStreamRequest: "/v1/chat/completions",
                },
            },
        }, nil
    }
    return nil, fmt.Errorf("provider %s not supported", provider)
}

Configuration Options

Allowed Request Types

Control which operations your custom provider can perform. The behavior is:

If allowed_requests is not specified: All operations are allowed by default
If allowed_requests is specified: Only the fields set to true are allowed, all others default to false

Available operations:

text_completion: Legacy text completion requests
text_completion_stream: Streaming text completion requests
chat_completion: Standard chat completion requests
chat_completion_stream: Streaming chat responses
responses: Standard responses requests
responses_stream: Streaming responses requests
embedding: Text embedding generation
speech: Text-to-speech conversion
speech_stream: Streaming text-to-speech
transcription: Speech-to-text conversion
transcription_stream: Streaming speech-to-text
rerank: Document reranking via /v1/rerank (OpenAI-compatible base only)

Base Provider Types

Custom providers can be built on these supported providers:

openai - OpenAI API
anthropic - Anthropic Claude
bedrock - AWS Bedrock
cohere - Cohere
gemini - Gemini
replicate - Replicate

Streaming Termination

Most OpenAI-compatible providers end a stream with a data: [DONE] marker, and Bifrost reads until it arrives so that a trailing usage-only chunk — which many providers send after finish_reason — is not lost. Bifrost also ends the stream on its own, with no configuration, when an upstream omits [DONE] after finish_reason:

the upstream closes the connection: the stream ends immediately
the upstream keeps the connection open and sends SSE heartbeat comments: the stream ends on the second consecutive comment after finish_reason, so a trailing usage chunk is still collected
the upstream keeps the connection open and sends nothing: the stream ends cleanly once stream_idle_timeout_in_seconds elapses, with the buffered finish_reason. Usage is unavailable for that request if it never arrived

Set does_not_send_done_marker to true when your upstream instead ends streams on finish_reason and never sends [DONE]. Bifrost then stops reading as soon as finish_reason arrives:

{
    "custom_provider_config": {
        "base_provider_type": "openai",
        "does_not_send_done_marker": true
    }
}

On its own, does_not_send_done_marker discards a trailing usage-only chunk, because that chunk arrives after the finish_reason the stream stopped on. The request is then recorded with zero tokens and zero cost, which affects logging, pricing, virtual-key usage, budgets and cost attribution. Add wait_for_usage if your upstream sends one.

Add wait_for_usage when your upstream ends on finish_reason but still sends that trailing usage chunk. Bifrost requests it on every stream via stream_options.include_usage, so this keeps the read loop open just long enough to collect it:

{
    "custom_provider_config": {
        "base_provider_type": "openai",
        "does_not_send_done_marker": true,
        "wait_for_usage": true
    }
}

With wait_for_usage the stream ends on whichever comes first: the usage chunk, two consecutive heartbeat comments, the upstream closing the connection, or stream_idle_timeout_in_seconds. If your upstream may go silent without ever sending usage, set network_config.stream_idle_timeout_in_seconds low (5, say) on that provider so the last case does not hold the request for the default 120 seconds.

Request Path Overrides

The request_path_overrides field allows you to override the default API endpoint paths for specific request types. This is useful when:

Connecting to custom or self-hosted model providers
Integrating with proxies that expect specific URL patterns
Using provider forks with modified API paths

Not Supported: request_path_overrides is not supported for gemini and bedrock base provider types due to their specialized API implementations.

The field accepts a mapping of request types to either custom paths or full URLs: Using Paths (relative to base_url):

{
    "request_path_overrides": {
        "chat_completion": "/v1/chat/completions",
        "chat_completion_stream": "/v1/chat/completions",
        "embedding": "/v1/embeddings",
        "text_completion": "/v1/completions"
    }
}

Using Full URLs (bypasses base_url):

{
    "request_path_overrides": {
        "chat_completion": "https://specific-endpoint.com/chat",
        "embedding": "http://another-service:8080/embeddings"
    }
}

When a full URL (with scheme and host) is provided in request_path_overrides, Bifrost will use that URL directly and ignore the base_url from network_config for that specific request type. This allows you to route different request types to completely different endpoints.

Example: OpenAI-Compatible Endpoint with Custom Paths

{
    "custom-llm": {
        "keys": [{ "name": "custom-llm-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "network_config": {
            "base_url": "https://your-openai-compatible-endpoint.com"
        },
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true
            },
            "request_path_overrides": {
                "chat_completion": "/api/v2/chat",
                "chat_completion_stream": "/api/v2/chat"
            }
        }
    }
}

In this example, instead of using OpenAI’s default /v1/chat/completions path, requests will be sent to https://custom-endpoint.example.com/api/v2/chat.

TLS for Self-Signed or Internal Certificates

When connecting to providers with HTTPS endpoints that use self-signed certificates or internal CAs (e.g., air-gapped environments, internal services), you can configure TLS in network_config:

Field	Type	Description
`insecure_skip_verify`	boolean	Disable TLS certificate verification. Use only for trusted internal environments. Not recommended for production.
`ca_cert_pem`	string	PEM-encoded CA certificate to trust for provider connections. Use when the endpoint uses a custom CA.

These options are mutually exclusive. Do not set insecure_skip_verify: true together with ca_cert_pem; provider config validation rejects that combination. Option 1: Skip verification (air-gapped / self-signed)

{
    "my-air-gapped-provider": {
        "keys": [{ "name": "key-1", "value": "env.API_KEY", "models": ["*"], "weight": 1.0 }],
        "network_config": {
            "base_url": "https://internal-llm.example.com",
            "insecure_skip_verify": true
        },
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true
            }
        }
    }
}

Option 2: Custom CA certificate (preferred when you have the CA)

{
    "my-internal-provider": {
        "keys": [{ "name": "key-1", "value": "env.API_KEY", "models": ["*"], "weight": 1.0 }],
        "network_config": {
            "base_url": "https://internal-llm.example.com",
            "ca_cert_pem": "-----BEGIN CERTIFICATE-----\n...\n-----END CERTIFICATE-----"
        },
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true
            }
        }
    }
}

Using insecure_skip_verify disables all certificate verification and is insecure. Prefer ca_cert_pem when you have the CA certificate. Only use insecure_skip_verify in trusted, isolated environments (e.g., air-gapped networks).

Use Cases

1. Environment-Specific Configurations

Create different configurations for production, staging, and development environments:

{
    "openai-production": {
        "keys": [{ "name": "openai-prod-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true,
                "embedding": true,
                "speech": true,
                "speech_stream": true
            }
        }
    },
    "openai-staging": {
        "keys": [{ "name": "openai-stage-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true,
                "embedding": true,
                "speech": false,
                "speech_stream": false
            }
        }
    },
    "openai-dev": {
        "keys": [{ "name": "openai-dev-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": false,
                "embedding": false,
                "speech": false,
                "speech_stream": false
            }
        }
    }
}

2. Role-Based Access Control

Restrict capabilities based on user roles or team permissions. You can then create virtual keys for better management of who can access which providers, providing granular control over team permissions and resource usage. This integrates seamlessly with Bifrost’s governance features for comprehensive access control and monitoring:

{
    "openai-developers": {
        "keys": [{ "name": "openai-developers-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true,
                "embedding": true,
                "text_completion": true
            }
        }
    },
    "openai-analysts": {
        "keys": [{ "name": "openai-analysts-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "embedding": true
            }
        }
    },
    "openai-support": {
        "keys": [{ "name": "openai-support-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": false
            }
        }
    }
}

3. Feature Testing and Rollouts

Test new features with limited user groups:

{
    "openai-beta-streaming": {
        "keys": [{ "name": "openai-streaming-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": true,
                "embedding": false
            }
        }
    },
    "openai-stable": {
        "keys": [{ "name": "openai-stable-key-1", "value": "env.PROVIDER_API_KEY", "models": ["*"], "weight": 1.0 }],
        "custom_provider_config": {
            "base_provider_type": "openai",
            "allowed_requests": {
                "chat_completion": true,
                "chat_completion_stream": false,
                "embedding": true
            }
        }
    }
}

Making Requests

Use your custom provider name in requests:

# Request to custom provider
curl --location 'http://localhost:8080/v1/chat/completions' \
--header 'Content-Type: application/json' \
--data '{
    "model": "openai-custom/gpt-4o-mini",
    "messages": [
        {"role": "user", "content": "Hello!"}
    ]
}'

Relationship to Provider Configuration

Custom providers extend the standard provider configuration system. They inherit all the capabilities of their base provider while adding request type restrictions. Learn more about provider configuration:

Next Steps

Fallbacks - Automatic failover between providers
Load Balancing - Intelligent API key management with weighted load balancing
Governance - Advanced access control and monitoring

Overview

Quick Start

Release Cadence

Migration Guides

Migrate from other Gateway

SDK Integrations

Providers & Guides

MCP Gateway

Custom plugins

Open Source Features

Custom Providers

What Are Custom Providers?

Key Benefits

How to Configure

Configuration Options

Allowed Request Types

Base Provider Types

Streaming Termination

Request Path Overrides

TLS for Self-Signed or Internal Certificates

Use Cases

1. Environment-Specific Configurations

2. Role-Based Access Control

3. Feature Testing and Rollouts

Making Requests

Relationship to Provider Configuration

Next Steps

​What Are Custom Providers?

​Key Benefits

​How to Configure

​Configuration Options

​Allowed Request Types

​Base Provider Types

​Streaming Termination

​Request Path Overrides

​TLS for Self-Signed or Internal Certificates

​Use Cases

​1. Environment-Specific Configurations

​2. Role-Based Access Control

​3. Feature Testing and Rollouts

​Making Requests

​Relationship to Provider Configuration

​Next Steps

What Are Custom Providers?

Key Benefits

How to Configure

Configuration Options

Allowed Request Types

Base Provider Types

Streaming Termination

Request Path Overrides

TLS for Self-Signed or Internal Certificates

Use Cases

1. Environment-Specific Configurations

2. Role-Based Access Control

3. Feature Testing and Rollouts

Making Requests

Relationship to Provider Configuration

Next Steps