Bring your own model credentials

Bring your own credentials (BYOK) lets Stilla orchestrate work while model requests run on an account your organization controls. Your provider bills the model usage and applies its own quotas, data controls, and regional policies.

Organization administrators manage models under Settings → Organization → Models. Choose Add model, then pick one of the three setup types below.

Credentials are encrypted at rest and are not displayed again after saving.

Experimental feature

BYOK is rolling out gradually to organizations using credits-based billing. Stilla does not currently charge credits for BYOK model usage, but your model provider still charges your account. Contact support if the controls are not visible.

Built-in model with your API key

Use this option when you want a model from Stilla's built-in catalog to run against a provider account you pay for. Stilla keeps the model's tested context window, tool behavior, and API adapter; you provide only a display name, model, and key.

The model picker only shows models compatible with this credential type.

Provider	What it can run	How to get a key
Anthropic	Built-in Claude models with a direct Anthropic route.	Create a standard API key in the Anthropic Console. The Anthropic access guide also covers billing and team setup.
OpenAI	Built-in GPT models with a direct OpenAI route.	Create a project key under OpenAI API keys. Use a normal project key, not an organization admin key. See OpenAI authentication.
Google Cloud API key	Built-in Gemini models through Agent Platform express mode.	Create a key in Agent Platform Studio or follow Google's Agent Platform API key guide. This key type supports Gemini `generateContent`; it does not unlock Claude or other partner models.

Create a dedicated provider key

Enable billing and model access with the provider. Prefer a project or service credential made only for Stilla, with the narrowest permissions the provider offers.

Choose Built-in model + your key

In Stilla, enter a recognizable display name, select a compatible model, and paste the key.

Google Cloud Agent Platform (formerly Vertex AI)

Use Agent Platform when requests should run in your Google Cloud project. Stilla supports chat models from Google and other Model Garden providers through these Agent Platform API contracts:

Google Gen AI for Gemini models
Anthropic Messages for Claude partner models
OpenAI-compatible Chat Completions for managed MaaS models, self-deployed endpoints, and OpenAI-shaped publisher rawPredict APIs such as Mistral

Agent Platform models are configured independently of Stilla's built-in model list. Choose the API contract the model exposes, then supply its Agent Platform endpoint URL and exact provider model ID.

Prepare Google Cloud

Create or select a Google Cloud project

Attach a billing account, then enable the Agent Platform API.

Enable each model

Open Model Garden, select the model's managed API or API Service card, and choose Enable. Accept provider terms when prompted. Google documents this flow for Claude partner models and open-model MaaS.

Create a dedicated service account

In IAM → Service Accounts, create an account for Stilla and grant it Agent Platform User (roles/aiplatform.user) in the project. Do not grant Owner or Editor just to make model calls.

Download a JSON key

Open the service account, choose Keys → Add key → Create new key → JSON, and store the download securely. Google's service-account key guide explains the required permissions and organization-policy restrictions.

Keep the service-account key secure

A service-account JSON key is required for Agent Platform models. Treat it like a password: keep the account dedicated and least-privileged.

Add the Agent Platform model to Stilla

Choose Agent Platform in Stilla and give the model a recognizable name. Select the API contract described above, then copy the endpoint URL and model ID from the model's sample code in Model Garden. Paste the complete service-account JSON key.

You can paste the endpoint URL exactly as Google provides it—Stilla handles validation and routing. Set the context-window and output-token limits if you know them, or leave them blank to use the defaults.

Custom endpoint

Use a custom endpoint for a model or gateway that is not in Stilla's built-in catalog. The endpoint must be publicly reachable over HTTPS.

The provider does not need an explicit Stilla integration. Any provider or gateway can work, including providers such as OpenCode Zen and Fireworks AI, if its public endpoint supports API-key authentication and streaming responses.

Select the API your provider supports and paste the endpoint URL it gives you. Stilla supports:

OpenAI Responses
OpenAI Chat Completions
Anthropic Messages
Google Gemini

Get the gateway credential

Create an API key with the endpoint operator. There is no universal key issuer for custom endpoints; the key must be valid for the URL and model ID you enter.

Describe the model

Enter the exact provider-side model ID. Optionally set its context window and maximum output tokens.

Rotation and troubleshooting

Edit a model to replace its API key or Agent Platform service-account JSON. Stilla verifies the new credential before saving it; the old value remains active if verification fails.

Removing a model discards its stored credential. The model's name remains attached to existing conversations so they remain understandable.

Common setup failures:

Authentication failed: Create a fresh key, confirm billing is active, and make sure it belongs to the intended provider project or workspace.
Model not found or access denied: Enable the model, accept its terms, check the exact model ID, and confirm your account has access.
Agent Platform project or region error: Copy an endpoint from the model's Google Cloud sample code and confirm its /projects/.../locations/... values. Partner-model regions can differ from Gemini regions.
Service-account key creation is unavailable: Check the iam.disableServiceAccountKeyCreation organization policy or ask a Google Cloud organization administrator.
Custom endpoint rejected: Use a public https:// URL. Private-network endpoints and URLs containing embedded usernames or passwords are not supported.
Verification times out: Confirm the provider is healthy and the endpoint can return a minimal generation request promptly, then try again.

For help, contact Stilla support with the model name, setup type, provider error, and Agent Platform project/location or custom endpoint host. Never send the API key or service-account JSON.