Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
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+++ disableToc = false title = "Model Aliases" weight = 14 url = "/features/model-aliases/" +++
A model alias is a model name that redirects all traffic to another
configured model. Declare gpt-4 as an alias of my-llama-3 and every client
calling gpt-4 is served by my-llama-3 with no client reconfiguration: the
clients keep their existing model name while you control what answers them on
the server side.
Declaring an alias
Create a minimal config file in your models directory:
name: gpt-4
alias: my-llama-3
That is the whole config: a name (the alias clients call) and an alias key
(the target that actually serves the request).
Rules and behavior
- The target (
my-llama-3) must be an existing, non-alias, enabled model. You cannot point an alias at a missing model, a disabled model, or another alias (no chains). - Aliases are 1:1. One alias maps to exactly one target.
- The target can be swapped live by editing the config file, calling the API, using the UI, or asking the assistant. No restart is required.
- Both
gpt-4andmy-llama-3appear inGET /v1/models. - Responses echo the requested alias: a call to
gpt-4returnsgpt-4in the responsemodelfield, not the target name. - Usage accounting records both sides: requested
gpt-4, servedmy-llama-3. - Aliases work for every modality (chat, embeddings, audio, images, and so on).
To serve a name from several models with automatic fallback, use a [failover chain]({{%relref "features/model-failover" %}}).
Managing aliases
You can create, swap, and remove aliases from any of the management surfaces.
Web UI
Open Add Model and pick the Alias / Routing template, then set a name and a target. To re-point an existing alias, edit it and change the target.
REST API
- Create:
POST /models/import - Swap the target:
PATCH /api/models/config-json/:name - List all aliases:
GET /api/aliases - Delete:
POST /models/delete/:name
Assistant and MCP
The LocalAI Assistant (and the MCP server) expose the same operations as tools:
set_alias, list_aliases, and delete_model.
{{% notice note %}}
You cannot turn an existing real model into an alias. If you run set_alias
(or PATCH /api/models/config-json/:name) against a name that is already a real,
non-alias model, the request is rejected. An alias is a pure redirect, so it
must not carry a backend or parameters.model; a real model does, and merging
an alias onto it produces an invalid config that validation refuses with
alias config ... must not set backend or parameters.model. This is intentional:
it stops a stray set_alias call from clobbering a model that is serving.
To add an alias, point a new name at the target instead of reusing an existing model's name. Re-pointing an existing alias at a different target is fully supported and is the live-swap path: the alias config has no backend of its own, so swapping its target stays a valid pure redirect. {{% /notice %}}
Aliases as deployment slots (distributed mode)
In [distributed mode]({{%relref "features/distributed-mode" %}}) an alias can
carry a scheduling rule. POST /api/nodes/scheduling accepts an alias for
model_name, and the rule then governs whatever model the alias points at:
curl -X POST http://frontend:8080/api/nodes/scheduling \
-H "Content-Type: application/json" \
-d '{"model_name": "production", "node_selector": {"tier": "gpu"}, "min_replicas": 2}'
Re-point production and the placement policy follows it, so the alias behaves
as a stable slot whose contents you can swap. Because a replica is shared by
every name that resolves to it, only one rule may govern a given model at a
time. See [Scheduling a model alias]({{%relref "features/distributed-mode" %}}#scheduling-a-model-alias).
Limits
Aliases are a static 1:1 redirect. For classifier-based or load-balanced selection across several downstream models, use the intelligent router in the [Middleware]({{%relref "operations/middleware" %}}) feature instead.