llama-swap is designed to be very simple: one binary, one configuration file.
models:
model1:
cmd: llama-server --port ${PORT} --model /path/to/model.ggufThis is enough to launch llama-server to serve model1. Of course, llama-swap is about making it possible to serve many models:
models:
model1:
cmd: llama-server --port ${PORT} -m /path/to/model.gguf
model2:
cmd: llama-server --port ${PORT} -m /path/to/another_model.gguf
model3:
cmd: llama-server --port ${PORT} -m /path/to/third_model.ggufWith this configuration models will be hot swapped and loaded on demand. The special ${PORT} macro provides a unique port per model which is useful if you want to run multiple models at the same time with the matrix feature.
llama-swap is also about customizability. You can use any CLI flag available:
models:
model1:
cmd: | # support for multi-line
llama-server --PORT ${PORT} -m /path/to/model.gguf
--ctx-size 8192
--jinja
--cache-type-k q8_0
--cache-type-v q8_0llama-swap supports any OpenAI API compatible server. If you can run it on the CLI llama-swap will be able to manage it. Even if it's run in Docker or Podman containers.
models:
"Q3-30B-CODER-VLLM":
name: "Qwen3 30B Coder vllm AWQ (Q3-30B-CODER-VLLM)"
# cmdStop provides a reliable way to stop containers
cmdStop: docker stop vllm-coder
cmd: |
docker run --init --rm --name vllm-coder
--runtime=nvidia --gpus '"device=2,3"'
--shm-size=16g
-v /mnt/nvme/vllm-cache:/root/.cache
-v /mnt/ssd-extra/models:/models -p ${PORT}:8000
vllm/vllm-openai:v0.10.0
--model "/models/cpatonn/Qwen3-Coder-30B-A3B-Instruct-AWQ"
--served-model-name "Q3-30B-CODER-VLLM"
--enable-expert-parallel
--swap-space 16
--max-num-seqs 512
--max-model-len 65536
--max-seq-len-to-capture 65536
--gpu-memory-utilization 0.9
--tensor-parallel-size 2
--trust-remote-codellama-swap supports many more features to customize how you want to manage your environment.
| Feature | Description |
|---|---|
ttl |
automatic unloading of models after a timeout |
macros |
reusable snippets to use in configurations |
matrix |
run multiple models at a time |
hooks |
event driven functionality |
env |
define environment variables per model |
aliases |
serve a model with different names |
filters |
modify requests before sending to the upstream |
... |
And many more tweaks |
Note
Always check config.example.yaml for the most up to date reference for all example configurations.
# add this modeline for validation in vscode
# yaml-language-server: $schema=https://raw.githubusercontent.com/mostlygeek/llama-swap/refs/heads/main/config-schema.json
#
# llama-swap YAML configuration example
# -------------------------------------
#
# 💡 Tip - Use an LLM with this file!
# ====================================
# This example configuration is written to be LLM friendly. Try
# copying this file into an LLM and asking it to explain or generate
# sections for you.
# ====================================
# Usage notes:
# - Below are all the available configuration options for llama-swap.
# - Settings noted as "required" must be in your configuration file
# - Settings noted as "optional" can be omitted
# healthCheckTimeout: number of seconds to wait for a model to be ready to serve requests
# - optional, default: 120
# - minimum value is 15 seconds, anything less will be set to this value
healthCheckTimeout: 500
# logLevel: sets the logging value
# - optional, default: info
# - Valid log levels: debug, info, warn, error
logLevel: info
# logTimeFormat: enables and sets the logging timestamp format
# - optional, default (disabled): ""
# - Valid values: "", "ansic", "unixdate", "rubydate", "rfc822", "rfc822z",
# "rfc850", "rfc1123", "rfc1123z", "rfc3339", "rfc3339nano", "kitchen",
# "stamp", "stampmilli", "stampmicro", and "stampnano".
# - For more info, read: https://pkg.go.dev/time#pkg-constants
logTimeFormat: ""
# logToStdout: controls what is logged to stdout
# - optional, default: "proxy"
# - valid values:
# - "proxy": logs generated by llama-swap when swapping models,
# handling requests, etc.
# - "upstream": a copy of an upstream processes stdout logs
# - "both": both the proxy and upstream logs interleaved together
# - "none": no logs are ever written to stdout
logToStdout: "proxy"
# metricsMaxInMemory: maximum number of metrics to keep in memory
# - optional, default: 1000
# - controls how many metrics are stored in memory before older ones are discarded
# - useful for limiting memory usage when processing large volumes of metrics
metricsMaxInMemory: 1000
# captureBuffer: how many MBs to allocate for storing request/response captures
# - optional, default: 10
# - set to 0 to disable
captureBuffer: 15
# startPort: sets the starting port number for the automatic ${PORT} macro.
# - optional, default: 5800
# - the ${PORT} macro can be used in model.cmd and model.proxy settings
# - it is automatically incremented for every model that uses it
startPort: 10001
# sendLoadingState: inject loading status updates into the reasoning (thinking)
# field
# - optional, default: false
# - when true, a stream of loading messages will be sent to the client in the
# reasoning field so chat UIs can show that loading is in progress.
# - see #366 for more details
sendLoadingState: true
# includeAliasesInList: present aliases within the /v1/models OpenAI API listing
# - optional, default: false
# - when true, model aliases will be output to the API model listing duplicating
# all fields except for Id so chat UIs can use the alias equivalent to the original.
includeAliasesInList: false
# globalTTL: the default TTL in seconds before unloading a model
# - optional, default: 0 (never automatically unload)
# - must be >= 0
globalTTL: 0
# macros: a dictionary of string substitutions
# - optional, default: empty dictionary
# - macros are reusable snippets
# - used in a model's cmd, cmdStop, proxy, checkEndpoint, filters.stripParams
# - useful for reducing common configuration settings
# - macro names are strings and must be less than 64 characters
# - macro names must match the regex ^[a-zA-Z0-9_-]+$
# - macro names must not be a reserved name: PORT or MODEL_ID
# - macro values can be numbers, bools, or strings
# - macros can contain other macros, but they must be defined before they are used
# - environment variables can be referenced with ${env.VAR_NAME} syntax
# - env macros are substituted first, before regular macros
# - if the env var is not set, config loading will fail with an error
macros:
# Example of a multi-line macro
"latest-llama": >
/path/to/llama-server/llama-server-ec9e0301
--port ${PORT}
"default_ctx": 4096
# Example of macro-in-macro usage. macros can contain other macros
# but they must be previously declared.
"default_args": "--ctx-size ${default_ctx}"
# Example of environment variable macros
# - ${env.VAR_NAME} pulls the value from the system environment
# - useful for paths, secrets, or machine-specific configuration
"models_dir": "${env.HOME}/models"
# apiKeys: require an API key when making requests to inference endpoints
# - optional, default: []
# - when empty (the default) authorization will not be checked as llama-swap is default-allow
# - each key is a non-empty string
apiKeys:
- "sk-hunter2"
# tip, one liner: printf "sk-%s\n" "$(head -c 48 /dev/urandom | base64 )"
- "sk-gyCPiKUcIfPlaM4OSMZekkprgijPx6+OsmQs8Rsg0xZ9qpy6gKWsIKqHOk+cgXVx"
# use environment variable macros to keep secrets out of the config
- "${env.API_KEY_1}"
- "${env.API_KEY_2}"
# models: a dictionary of model configurations
# - required
# - each key is the model's ID, used in API requests
# - model settings have default values that are used if they are not defined here
# - the model's ID is available in the ${MODEL_ID} macro, also available in macros defined above
# - below are examples of the all the settings a model can have
models:
# keys are the model names used in API requests
"gpt-oss-120b":
# macros: a dictionary of string substitutions specific to this model
# - optional, default: empty dictionary
# - macros defined here override macros defined in the global macros section
# - model level macros follow the same rules as global macros
macros:
"default_ctx": 16384
"temp": 0.7
# cmd: the command to run to start the inference server.
# - required
# - it is just a string, similar to what you would run on the CLI
# - using `|` allows for comments in the command, these will be parsed out
# - macros can be used within cmd
cmd: |
# ${latest-llama} is a macro that is defined above
${latest-llama}
--model path/to/gpt-oss-120B.gguf
--ctx-size ${default_ctx}
--temperature ${temp}
# name: a display name for the model
# - optional, default: empty string
# - if set, it will be used in the v1/models API response
# - if not set, it will be omitted in the JSON model record
name: "gpt-oss 120B"
# description: a description for the model
# - optional, default: empty string
# - if set, it will be used in the v1/models API response
# - if not set, it will be omitted in the JSON model record
description: "A thinking model from OpenAI"
# env: define an array of environment variables to inject into cmd's environment
# - optional, default: empty array
# - each value is a single string
# - in the format: ENV_NAME=value
env:
- "CUDA_VISIBLE_DEVICES=0,1,2"
# proxy: the URL where llama-swap routes API requests
# - optional, default: http://localhost:${PORT}
# - if you used ${PORT} in cmd this can be omitted
# - if you use a custom port in cmd this *must* be set
proxy: http://127.0.0.1:8999
# checkEndpoint: URL path to check if the server is ready
# - optional, default: /health
# - endpoint is expected to return an HTTP 200 response
# - all requests wait until the endpoint is ready or fails
# - use "none" to skip endpoint health checking
checkEndpoint: /custom-endpoint
# ttl: automatically unload the model after ttl seconds
# - optional, default: -1 (use global default)
# - ttl values must be a value greater than or equal to 0
# - a ttl of -1 will use the global TTL value as the default
# - a ttl of 0 will mean never unload
# - a value of 0 disables automatic unloading of the model
ttl: 60
# useModelName: override the model name that is sent to upstream server
# - optional, default: ""
# - useful for when the upstream server expects a specific model name that
# is different from the model's ID
useModelName: "openai/gpt-oss-120B"
# filters: a dictionary of filter settings
# - optional, default: empty dictionary
# - same capabilities as peer filters (stripParams, setParams)
filters:
# stripParams: a comma separated list of parameters to remove from the request
# - optional, default: ""
# - useful for server side enforcement of sampling parameters
# - the `model` parameter can never be removed
# - can be any JSON key in the request body
# - recommended to stick to sampling parameters
stripParams: "temperature, top_p, top_k"
# setParams: a dictionary of parameters to set/override in requests
# - optional, default: empty dictionary
# - useful for enforcing specific parameter values
# - protected params like "model" cannot be overridden
# - values can be strings, numbers, booleans, arrays, or objects
# - always runs for the model
setParams:
# Example: enforce specific sampling parameters
temperature: 0.7
top_p: 0.9
# setParamsByID: a dictionary of parameters to set based the model ID
# - optional, default: empty dictionary
# - combine with aliases to create variant behaviour without reloading the model
# - parameters are set in the request body JSON
# - run after setParams so it will override any settings
# - protected params like "model" cannot be overridden
# - values can be strings, numbers, booleans, arrays, or objects
# - model aliases will be automatically created for each key
setParamsByID:
"${MODEL_ID}":
chat_template_kwargs:
reasoning_effort: medium
"${MODEL_ID}:high":
chat_template_kwargs:
reasoning_effort: high
"${MODEL_ID}:low":
chat_template_kwargs:
reasoning_effort: low
# aliases: alternative model names that this model configuration is used for
# - optional, default: empty array
# - aliases must be unique globally
# - useful for impersonating a specific model
aliases:
- "gpt-4o-mini"
# metadata: a dictionary of arbitrary values that are included in /v1/models
# - optional, default: empty dictionary
# - while metadata can contains complex types it is recommended to keep it simple
# - metadata is only passed through in /v1/models responses
metadata:
# port will remain an integer
port: ${PORT}
# the ${temp} macro will remain a float
temperature: ${temp}
note: "The ${MODEL_ID} is running on port ${PORT} temp=${temp}, context=${default_ctx}"
a_list:
- 1
- 1.23
- "macros are OK in list and dictionary types: ${MODEL_ID}"
an_obj:
a: "1"
b: 2
# objects can contain complex types with macro substitution
# becomes: c: [0.7, false, "model: llama"]
c: ["${temp}", false, "model: ${MODEL_ID}"]
# concurrencyLimit: overrides the allowed number of active parallel requests to a model
# - optional, default: 0
# - useful for limiting the number of active parallel requests a model can process
# - must be set per model
# - any number greater than 0 will override the internal default value of 10
# - any requests that exceeds the limit will receive an HTTP 429 Too Many Requests response
# - recommended to be omitted and the default used
concurrencyLimit: 0
# sendLoadingState: overrides the global sendLoadingState setting for this model
# - optional, default: undefined (use global setting)
sendLoadingState: false
# timeouts: configure proxy connection timeouts for this model
# - optional, defaults shown below
# - useful for models running on slower hardware that need longer timeouts
# - connect: TCP dial connection timeout in seconds, default: 30 seconds
# - keepalive: TCP connection keepalive timeout, default: 30 seconds
# - responseHeader: time to wait for response headers in seconds, default: 0 (no timeout)
# - tlsHandshake: TLS handshake timeout in seconds, default: 10 seconds
# - idleConn: idle connection timeout in seconds, default: 90 seconds
# - set any value to 0 to disable that timeout (not recommended)
timeouts:
connect: 30
keepalive: 0
responseHeader: 60
tlsHandshake: 10
idleConn: 90
# Unlisted model example:
"qwen-unlisted":
# unlisted: boolean, true or false
# - optional, default: false
# - unlisted models do not show up in /v1/models api requests
# - can be requested as normal through all apis
unlisted: true
cmd: llama-server --port ${PORT} -m Llama-3.2-1B-Instruct-Q4_K_M.gguf -ngl 0
# Docker example:
# container runtimes like Docker and Podman can be used reliably with
# a combination of cmd, cmdStop, and ${MODEL_ID}
"docker-llama":
proxy: "http://127.0.0.1:${PORT}"
cmd: |
docker run --name ${MODEL_ID}
--init --rm -p ${PORT}:8080 -v /mnt/nvme/models:/models
ghcr.io/ggml-org/llama.cpp:server
--model '/models/Qwen2.5-Coder-0.5B-Instruct-Q4_K_M.gguf'
# cmdStop: command to run to stop the model gracefully
# - optional, default: ""
# - useful for stopping commands managed by another system
# - the upstream's process id is available in the ${PID} macro
#
# When empty, llama-swap has this default behaviour:
# - on POSIX systems: a SIGTERM signal is sent
# - on Windows, calls taskkill to stop the process
# - processes have 5 seconds to shutdown until forceful termination is attempted
cmdStop: docker stop ${MODEL_ID}
# =============================================================================
# matrix: run concurrent models with a solver-based swap DSL
# =============================================================================
#
# Note:
# A config must use either a matrix or legacy groups, not both. A configuration error
# will occur if both are defined. Configuration examples for legacy Groups can be found:
# https://github.com/mostlygeek/llama-swap/blob/40e39f7/config.example.yaml#L334-L396
#
# The matrix declares valid combinations of models that can run concurrently.
# When a model is requested, the solver finds the cheapest way to make it
# available by evicting as few (and least costly) running models as possible.
#
# Solver behavior:
# 1. Request arrives for model X
# 2. If X is already running, forward immediately. Done.
# 3. Find all sets containing X
# 4. For each candidate set, compute cost: sum of evict_costs for
# every running model NOT in that set
# 5. Pick lowest cost candidate. Ties broken by definition order.
# 6. Evict what needs to stop. Start X. Forward request.
#
# Subset semantics: a set [a, b, c] means any subset is valid.
# Only the requested model is started — others are not preloaded.
#
# A model not appearing in any set can only run alone.
#
matrix:
# vars: short names for models (alphanumeric, 1-8 chars)
# - required for sets and evict_costs settings
# - each entry is a short name to a real model ID. Do not use an alias
# - used to keep set DSL logic short and easier to read
# - sets and evict_costs only use identifiers defined in vars
vars:
g: gemma-model
q: qwen-model
m: mistral-model
v: voxtral-model
e: reranker-model
L: llama-70B
sd: stable-diffusion
# evict_costs: relative cost of losing a running model (default: 1)
evict_costs:
v: 50 # vllm backend, slow cold start
L: 30 # 70B weights, slow to load
# sets: named sets of concurrent model combinations
# Values are DSL strings with operators:
# & AND (models run together)
# | OR (alternatives)
# () grouping
# +ref inline another set's expression
#
# Expansion examples:
# "L" → [L]
# "a & b" → [a, b]
# "a | b" → [a], [b]
# "(a | b) & c" → [a, c], [b, c]
# "(a | b) & (c | d)" → [a,c], [a,d], [b,c], [b,d]
# "+llms & v" → expands llms inline, then applies & v
sets:
# LLM + TTS: switching between g/q/m won't evict v
# expands to: [g,v], [q,v], [m,v]
standard: "(g | q | m) & v"
# LLM + TTS + reranker
# expands to: [g,v,e], [q,v,e]
with_rerank: "(g | q) & v & e"
# LLM + image generation, no TTS
# expands to: [g,sd], [q,sd]
creative: "(g | q) & sd"
# 70B model uses all GPUs, can only run alone
# expands to: [L]
full: "L"
# hooks: a dictionary of event triggers and actions
# - optional, default: empty dictionary
# - the only supported hook is on_startup
hooks:
# on_startup: a dictionary of actions to perform on startup
# - optional, default: empty dictionary
# - the only supported action is preload
on_startup:
# preload: a list of model ids to load on startup
# - optional, default: empty list
# - model names must match keys in the models sections
# - when preloading multiple models at once, define a group
# otherwise models will be loaded and swapped out
preload:
- "llama"
# peers: a dictionary of remote peers and models they provide
# - optional, default empty dictionary
# - peers can be another llama-swap
# - peers can be any server that provides the /v1/ generative api endpoints supported by llama-swap
peers:
# keys is the peer'd ID
llama-swap-peer:
# proxy: a valid base URL to proxy requests to
# - required
# - requested path to llama-swap will be appended to the end of the proxy value
proxy: http://192.168.1.23
# models: a list of models served by the peer
# - required
models:
- model_a
- model_b
- embeddings/model_c
openrouter:
proxy: https://openrouter.ai/api
# apiKey: a string key to be injected into the request
# - optional, default: ""
# - if blank, no key will be added to the request
# - key will be injected into headers: Authorization: Bearer <key> and x-api-key: <key>
# - can be a string or a macro
apiKey: ${env.OPENROUTER_API_KEY}
models:
- meta-llama/llama-3.1-8b-instruct
- qwen/qwen3-235b-a22b-2507
- deepseek/deepseek-v3.2
- z-ai/glm-4.7
- moonshotai/kimi-k2-0905
- minimax/minimax-m2.1
# timeouts: configure proxy connection timeouts for this peer
# - optional, defaults shown below
# - useful when the peer runs on slower hardware
# - set any value to 0 to disable that timeout (not recommended)
timeouts:
connect: 30
keepalive: 30
responseHeader: 60
tlsHandshake: 10
idleConn: 90
# filters: a dictionary of filter settings for peer requests
# - optional, default: empty dictionary
# - same capabilities as model filters (stripParams, setParams)
filters:
# stripParams: a comma separated list of parameters to remove from the request
# - optional, default: ""
# - useful for removing parameters that the peer doesn't support
# - the `model` parameter can never be removed
stripParams: "temperature, top_p"
# setParams: a dictionary of parameters to set/override in requests to this peer
# - optional, default: empty dictionary
# - useful for injecting provider-specific settings like data retention policies
# - protected params like "model" cannot be overridden
# - values can be strings, numbers, booleans, arrays, or objects
setParams:
# Example: enforce zero-data-retention for OpenRouter
provider:
data_collection: "deny"
zdr: true