Custom Models (BYOK)
Connect your own API keys, use open source models, or run local models
The Droid CLI supports custom model configurations through BYOK (Bring Your Own Key). Use your own OpenAI or Anthropic keys, connect to any open source model providers, or run models locally on your hardware.
For Factory-managed models and multipliers, see Available Models. For org-level restrictions on custom models, base URLs, and provider access, see Enterprise Controls.
Your API keys remain local and are not uploaded to Factory servers. Custom models are only available in the CLI and won't appear in Factory's web or mobile platforms.
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Configuration reference
Add custom models to ~/.factory/settings.json under the customModels array:
{
"customModels": [
{
"model": "your-model-id",
"displayName": "My Custom Model",
"baseUrl": "https://api.provider.com/v1",
"apiKey": "${PROVIDER_API_KEY}",
"provider": "generic-chat-completion-api",
"maxOutputTokens": 16384
}
]
}In settings.json (and settings.local.json), apiKey supports environment variable references using ${VAR_NAME} syntax. For example, "apiKey": "${PROVIDER_API_KEY}" reads from the environment variable named PROVIDER_API_KEY (for example: export PROVIDER_API_KEY=your_key_here).
Legacy support: Custom models in ~/.factory/config.json using snake_case field names (custom_models, base_url, etc.) are still supported for backwards compatibility. Both files are loaded and merged, with settings.json taking priority. Environment variable expansion for apiKey does not apply to legacy config.json.
Supported fields
modelstringrequiredModel identifier sent via API (e.g.,
claude-sonnet-4-5-20250929,gpt-5.3-codex,qwen3:4b).displayNamestringHuman-friendly name shown in model selector.
baseUrlstringrequiredAPI endpoint base URL.
apiKeystringrequiredYour API key for the provider. Can't be empty. Supports environment variable references; see the Tip above.
providerstringrequiredProvider type that determines API compatibility. See the Understanding Providers section below.
maxOutputTokensnumberMaximum output tokens for model responses.
noImageSupportbooleanSet to
trueto disable image inputs for this model.extraArgsobjectAdditional provider-specific arguments to include in API requests.
extraHeadersobjectAdditional HTTP headers to send with requests.
bedrockobjectAWS Bedrock routing options (
awsRegion,awsProfile,bedrockBaseUrl,awsAuthRefresh,awsCredentialExport). See AWS Bedrock.
Using extraArgs
Pass provider-specific parameters like temperature or top_p by adding an extraArgs object:
{
"extraArgs": {
"temperature": 0.7,
"top_p": 0.9
}
}Using extraHeaders
Add custom HTTP headers to API requests by adding an extraHeaders object:
{
"extraHeaders": {
"X-Custom-Header": "value",
"Authorization": "Bearer YOUR_TOKEN"
}
}AWS Bedrock
To route an Anthropic or OpenAI custom model through AWS Bedrock, add a bedrock object to the model config. Credentials are resolved through the standard AWS SDK provider chain (environment variables, shared config/credentials files, or an SSO/IAM profile).
{
"customModels": [
{
"model": "anthropic.claude-sonnet-4-5-20250929-v1:0",
"displayName": "Sonnet 4.5 [Bedrock]",
"provider": "anthropic",
"apiKey": "not-used-for-bedrock",
"bedrock": {
"awsRegion": "${AWS_REGION}",
"awsProfile": "${AWS_PROFILE}"
}
}
]
}Bedrock fields
| Field | Type | Description |
|---|---|---|
awsRegion | string | AWS region for Bedrock requests. Optional; when omitted, Droid falls back to the AWS default region chain. Supports ${VAR_NAME} interpolation. |
awsProfile | string | AWS profile name to resolve credentials and (as a last resort) a region. Supports ${VAR_NAME} interpolation. |
bedrockBaseUrl | string | Explicit Bedrock endpoint override. Accepts a full URL or a ${VAR_NAME} reference that expands to one. |
awsAuthRefresh | string | Shell command run to refresh AWS credentials before requests. |
awsCredentialExport | string | Shell command whose output exports AWS credentials into the request environment. |
Environment variable interpolation
Like apiKey, the awsRegion, awsProfile, and bedrockBaseUrl fields support ${VAR_NAME} references in settings.json/settings.local.json, expanded per workspace at parse time. This lets a single centrally-distributed customModels config resolve to the correct value in each environment:
{
"bedrock": {
"awsRegion": "${AWS_REGION}"
}
}If a referenced variable is not set, Droid fails fast with a clear error naming the missing variable instead of sending the literal ${VAR_NAME} to AWS.
awsAuthRefresh and awsCredentialExport are not expanded by the settings parser. They run through a shell, so ${VAR} in those commands is substituted by the shell at run time against the child process environment.
Region resolution
When awsRegion is omitted, Droid resolves the region using the AWS default chain, in order:
- 1
AWS_REGION - 2
AWS_DEFAULT_REGION - 3The
regionset on the resolved AWS profile in~/.aws/config
If none of these supply a region, Droid fails fast with a clear error rather than silently defaulting, so requests never target a region the workspace did not choose (important for VPC-endpoint region affinity).
Understanding providers
Factory supports three provider types that determine API compatibility:
| Provider | API Format | Use For | Documentation |
|---|---|---|---|
anthropic | Anthropic Messages API (v1/messages) | Anthropic models on their official API or compatible proxies | Anthropic Messages API |
openai | OpenAI Responses API | OpenAI models on their official API or compatible proxies. Required for the newest models like GPT-5 and GPT-5-Codex. | OpenAI Responses API |
generic-chat-completion-api | OpenAI Chat Completions API | OpenRouter, Fireworks, Together AI, Ollama, vLLM, and most open-source providers | OpenAI Chat Completions API |
Factory is actively verifying Droid's performance on popular models, but we cannot guarantee that all custom models will work out of the box. Only Anthropic and OpenAI models accessed via their official APIs are fully tested and benchmarked.
Model Size Consideration: Models below 30 billion parameters have shown significantly lower performance on agentic coding tasks. While these smaller models can be useful for experimentation and learning, they are generally not recommended for production coding work or complex software engineering tasks.
Provider reference
Every provider below works through the configuration above. Use provider: "generic-chat-completion-api" unless you are calling OpenAI's or Anthropic's official API.
| Provider | baseUrl | Example model |
|---|---|---|
| OpenAI (official) | https://api.openai.com/v1 | gpt-5.3-codex (set provider: "openai") |
| Anthropic (official) | https://api.anthropic.com | claude-sonnet-4-5-20250929 (set provider: "anthropic") |
| OpenRouter | https://openrouter.ai/api/v1 | openai/gpt-oss-20b |
| Fireworks AI | https://api.fireworks.ai/inference/v1 | accounts/fireworks/models/deepseek-v3p1-terminus |
| DeepInfra | https://api.deepinfra.com/v1/openai | Qwen/Qwen3-Coder-480B-A35B-Instruct-Turbo |
| Groq | https://api.groq.com/openai/v1 | moonshotai/kimi-k2-instruct-0905 |
| Baseten | https://inference.baseten.co/v1 | your deployed model ID |
| Hugging Face | https://router.huggingface.co/v1 | openai/gpt-oss-120b:fireworks-ai |
| Google Gemini | https://generativelanguage.googleapis.com/v1beta/ | gemini-2.5-pro |
Local models
Run models on your own hardware with an OpenAI-compatible server, then point baseUrl at it:
- Ollama: set
baseUrltohttp://localhost:11434/v1with any non-emptyapiKey, and raise the context window to at least 32k (for exampleOLLAMA_CONTEXT_LENGTH=32000 ollama serve). Models with 30B+ parameters are recommended for agentic coding, and Ollama Cloud models work through the same endpoint. - LM Studio: set
baseUrltohttp://localhost:1234/v1, load an OpenAI-compatible model, and start its local server.
Prompt caching
The Droid CLI automatically uses prompt caching when available to reduce API costs:
- Official providers (
anthropic,openai): Factory attempts to use prompt caching via the official APIs. Caching behavior follows each provider's implementation and requirements. - Generic providers (
generic-chat-completion-api): Prompt caching support varies by provider and cannot be guaranteed. Some providers may support caching, while others may not.
Verifying prompt caching
To check if prompt caching is working correctly with your custom model:
- 1Run a conversation with your custom model
- 2Use the
/costcommand in the Droid CLI to view cost breakdowns - 3Look for cache hit rates and savings in the output
If you're not seeing expected caching savings, consult your provider's documentation about their prompt caching support and requirements.
Using custom models
Once configured, access your custom models in the CLI:
- 1Use the
/modelcommand - 2Your custom models appear in a separate "Custom models" section below Factory-provided models
- 3Select any model to start using it
Custom models display with the name you set in displayName, making it easy to identify different providers and configurations.