Add External Keys (BYOK)

Bring Your Own Key — Connect your own provider credentials to FastRouter and route traffic through your own accounts while retaining FastRouter's full routing, observability, and governance layer.

Overview

FastRouter's External Keys feature lets organization owners attach API credentials from any supported LLM provider directly to their organization. Traffic routes through your own provider account, preserving your negotiated pricing, rate limits, and compliance posture.

Each integration is a named, project-scoped record pairing a provider with credentials and a model selection. Multiple integrations can coexist for the same provider — for example, separate Anthropic integrations for production and research, each scoped to different projects.

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Prerequisites

• You must be an Organization Owner to create, edit, or delete integrations.

• Project Admins and Developers can use integrations within their project scope but cannot modify credentials.

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Supported providers

Provider	Credential type	Notes
Anthropic Claude	API Key
Baseten	API Key
DeepInfra	API Key
FAL AI	API Key
Fireworks AI	API Key
Google AI Studio	API Key
Google Vertex AI	Service Account	Service Account JSON required
Groq	API Key
Microsoft Azure	API Key	Resource Name and deployment config required
Minimax	API Key
Moonshot	API Key
Nebius	API Key
OpenAI	API Key
Perplexity AI	API Key
Pollo AI	API Key
Together AI	API Key
X-AI	API Key

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Creating an integration

Navigate to Setup → External Keys and click New Integration. The wizard has three steps.

Step 1 — Select a provider

Choose from the list above. Use the search box to filter by name.

Select a provider

Step 2 — Integration details

Enter configurations and credentials.

Field	Required	Notes
Name	Yes	Display name, e.g. "Anthropic Production"
Provider Slug	Yes	Unique identifier used in API headers, gateway configs, and the Activity Log
Short Description	No
Project Scope	Yes	"All Projects" or one or more specific projects

The Provider Slug appears in your Activity Log on every request, making it easy to trace which credential was used.

Add provider key & configuration

Credential fields vary by provider. For most, you supply an API key. Three providers support multiple authentication modes:

Google Vertex AI

Auth mode	Required fields
Service Account File	JSON key file upload

Microsoft Azure

Auth mode	Required fields
Default (API Key)	API Key, Azure Resource Name, deployment config

Advanced options (collapsed by default)

• Custom Host — override the provider's default base URL. When set, select an API format: OpenAI-compatible, Anthropic-compatible, or Cohere-compatible.

• Custom Auth Headers — forwarded to your endpoint without logging.

Step 3 — Model provisioning

FastRouter catalog models only. Only models in the FastRouter Model Catalog are routable, even with auto-enable on. Contact support to request a model addition.

• Toggle catalog models on or off individually, or use All / None.

• For now, models from the catalog or custom models have to mapped per provider.

• [COMING SOON: Auto-enable — new catalog models from this provider are enabled on this integration automatically.]

Enable/disable specific provider models

Adding custom models

Use Add Custom Model to register fine-tuned or privately hosted models.

Field	Required	Notes
Model Slug	Yes	The model identifier used in API calls. Must be unique within this integration.
Base Model	No	An existing catalog model your custom model is API-compatible with. Tells FastRouter which request/response schema to use — no effect on pricing.
Custom Host	No	Override the endpoint for this specific model only.
Input / Output pricing	No	USD per 1M tokens, for cost tracking in the dashboard.
Additional token pricing	No	JSON for provider-specific token categories, e.g. {"cache_read_input_tokens": 0.30}

Configure custom models & endpoints

Note: Custom models can be edited or deleted at any time from the model list.

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Editing an integration

Click Edit on any integration card. The edit wizard has two steps — Integration Details and Model Provisioning. The provider cannot be changed after creation.

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Security

• Credentials are encrypted at rest and never returned in API responses after saving.

• Rate limits and costs are governed by your provider account, not FastRouter's shared key pools.

• Only Organization Owners can create, modify, or delete credentials.

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Using BYOK integrations

Once active, reference an integration via its Provider Slug in:

• Virtual Models — associate an alias with a specific integration

• Gateway Configs — use in fallback or load-balancing configurations

• Activity Log — every request shows the Provider Slug of the integration used