Pascal 1a87dcdc45
server + ui: SSE Replay Buffer (#23226)
* server: SSE replay buffer, survives client disconnect

Opt in on POST /v1/chat/completions when the client sends
X-Stream-Resume: 1 and a non empty X-Conversation-Id. The conv id is
the session identity end to end, no extra opaque token. The drain
runs detached server side and buffers SSE bytes, the generation
survives HTTP disconnect, F5, or lets users switch from iOS Safari
to another app without losing the actively generated response.

Routes:
  GET    /v1/stream/<conv_id>?from=N       replay
  GET    /v1/streams[?conversation_id=X]   list, drives sidebar spinners
  DELETE /v1/stream/<conv_id>              Stop, idempotent

Router parent fans out to children for list and delete, probes on GET
to route to the owner, fans out DELETE on POST so "one session per
conv" holds across model swaps.

WebUI: the layout snapshots /v1/streams at mount and on
visibilitychange, the sidebar reflects live inferences across all
convs. The chat page reattaches on mount, append vs fresh is detected
from existing content so continue mid stream keeps its prefix.

update_slots: on llama_memory_seq_rm refusal at a deep position, full
clear of the seq and reprefill from zero instead of GGML_ABORT.

OAI strict path unchanged when the opt in headers are absent.

* server: create stream session only after post_tasks succeeds

* server, ui: drop X-Stream-Resume, X-Conversation-Id alone enables the replay buffer

* server: drop magic 17, derive the X-Conversation-Id header length from sizeof at build time

* refactor: address review feedback from ngxson

* server-context: cleaning

* server-stream: fix use-after-free on rd

Guard stop_producer with a shared alive flag, flipped by on_stream_end
before rd dies. Prevents a late cancel (session eviction by a later
POST on the same conv_id, or a DELETE arriving after the producer
ended) from touching a destroyed rd.

* ui: fix cross-conversation contamination

Scope streaming flags per conv so one finishing does not unflag the
others, guard discoverActiveStream against concurrent runs to avoid
duplicate attaches, and stop racing syncRemoteRunningStreams for the
sidebar set.

* server-http: keep request alive in detached SSE drain

The response next() lambda may reach into *request via &req long
after on_complete reset the request shared_ptr. Capture request in
the detached thread so it outlives the drain.

* ui: address review feedback from coder543

Forward Authorization to /v1/stream and /v1/streams fetches, the resumable routes
must obey --api-key like the rest of the API.

Wrap reader.read() in a try/catch, the underlying connection drop rejects with
TypeError instead of resolving done=true, treat it as a premature end of stream
so the existing resume loop kicks in.

Freeze the model at session start in chatStreamingStates.model and thread it
through cancel and resume, the dropdown selection may have changed since the
POST and the server side identity is fixed at that time.

* format

* ui: remove unused selectedModelName

* server-stream: poll session->is_cancelled() in stream_aware_should_stop

Address review feedback from coder543. The cancel propagation through
rd.stop() relies on the slot eventually processing the cancel task and
posting a result that notifies the recv condvar, remove_waiting_task_ids
does not notify directly. Add a defensive poll on session->is_cancelled()
so the producer-side next() loop exits on its next iteration after
cancel() without waiting for the cancel task to round trip through a slot.

* server-stream, ui: replace GET /v1/streams with POST /v1/streams/lookup

Address review feedback from coder543. Listing live sessions leaks the
conversation_id of every concurrent user, which defeats the random UUID
unguessability. The new route takes {conversation_ids: [...]} in the
body and returns matches only for the ids the caller already owns, so
foreign UUIDs stay private. The router fans out the same POST to every
child and aggregates, the WebUI passes the convs visible in its sidebar.

* ui: read conv ids from IndexedDB in syncRemoteRunningStreams

The conversations store is not hydrated yet at +layout onMount, so the
sidebar spinners stayed off for background convs until the user clicked
on them. Read straight from the DB to dodge the init race.

* server-models: deduplicate stream lookup timeouts behind one constant

* ui: extract visibility kick grace into a stream constant, bump to 1000 ms

* make it safer & more simple

* server-stream: survive client disconnect via stream_pipe::finish_producer

After the RAII rewrite the generation stopped the moment the client
disconnected. httplib bails its content provider on the is_peer_alive
check at the top of write_content_chunked, so returning true from the
provider never keeps it producing: the response resets, rd is destroyed
and its task gets cancelled.

Reinstate the disconnect survival inside the pipe. stream_pipe gains
finish_producer, which pumps the response next() into the ring buffer
until the generation ends, and mark_producer_done for the clean wire
end. server-http only triggers them: mark before sink.done on a clean
close, finish in on_complete when the peer left early. No detach, no
stream logic in server-http beyond the trigger, and the strict OAI path
is untouched when no pipe is attached.

Known limitation: finish_producer pumps synchronously on the http
worker, so a disconnected stream keeps its worker busy until the
generation ends. A follow-up will move the drain off the http worker so
no worker is held.

* server-stream: drain disconnected streams on a manager owned thread

The previous commit pumped the post disconnect drain synchronously in
on_complete, on the http worker, so a disconnected stream kept its
worker busy until the generation ended. Under a wave of reloads or tab
closes that pins workers from the pool.

Move the drain off the http worker. on_complete now hands the response
to stream_session_manager::adopt_orphan, which pumps it to completion on
a manager owned thread and releases the worker at once. One thread per
disconnected stream still generating, stored in a list, joined and
reaped on the next adopt, by the GC, and at shutdown. No detach, the
thread lifecycle is fully owned by the manager. needs_drain gates the
handoff so a cleanly finished stream never spawns a thread, and the
strict OAI path stays untouched when no pipe is attached.

stop_gc now cancels sessions before finalizing them, so an in flight
drain sees is_cancelled and exits instead of blocking the shutdown join
until the generation ends naturally.

* ui: add missing JSDoc

* server-stream: drain on the http worker, drop the manager thread

Address @ngxson review: httplib runs a large dynamic pool and a worker
blocked in next() sits on a condvar instead of burning cpu, so draining
the rest of the generation on that worker is fine and much simpler than
a dedicated thread.

on_complete calls finish_producer directly again. Removes adopt_orphan,
the orphan thread list and its reaping, the stop_gc session cancel that
only existed to unblock those threads, and the now dead drain_shutdown
flag.

* server-stream: split stream_pipe into producer and consumer classes

Address @ngxson review: one class covering both ends was messy. stream_pipe
is now a base holding the session and is_cancelled, with stream_pipe_producer
(write, mark_producer_done, finish_producer, cleanup, finalizes on destruct)
and stream_pipe_consumer (read only, no finalize) deriving from it.

Drops the is_producer_ discriminator and its runtime guards, the type now
encodes the role. res.spipe is retyped to shared_ptr<stream_pipe_producer>
since it is only ever a producer. No behavior change.

* server-stream: rename producer methods to unix pipe semantics

Address @ngxson review: mark_producer_done becomes done(), finish_producer
becomes close(), matching a unix pipe write end. The producer_done_ member
follows as done_. write() is unchanged. No behavior change.

* server, ui: route resumable streams via a conv map, persist resume identity

Address ngxson review: drop the polling probe, proxy_post records a conv_id ->
model map and the stream routes resolve the owning child with one lookup. The
map is the single source of truth, the ::model suffix stays for child session
uniqueness but the router never parses it.

UI: the server keys a session by the POST time identity (conv::model), but reload
probed with the bare conv id and missed model tagged sessions, so F5 stopped the
stream and sidebar spinners stayed off. Persist the model and rebuild the exact
identity on resume, single conv and bulk sidebar both send it.

Add unit coverage for the identity round trip.

* ui: resolve continue target by id to stop cross-conversation flash on switch

* ui: skip stream resume when the abort is intentional

* server: move the conv id to model map into a self contained tracker

Address review from ngxson: server_models held two mutexes side by side, the
global one and a bare conv_model_mu guarding a loose map, which made the locking
hard to follow. Wrap the map and its lock in a small conv_model_tracker struct
that owns its mutex, one mutex per struct. The remember, lookup and forget
methods move inline into the tracker, server_models exposes a single conv_models
member and the routes call models.conv_models.lookup and friends. No behavior
change, the map stays the single source of truth for routing resumable streams
to a child.

* ui: replace stream magic values with enums and shared constants

Address review from allozaur: lift the inline literals around the resumable
stream code into named symbols so the intent is explicit and reusable.

* ui: fold the stream resume and discovery helpers into ChatService

Address review from allozaur: drop the two standalone stream-*.service files.
They were used only by the chat service and store, carried no shared state, and
did not follow the static class pattern the other services use, so a separate
abstraction was not warranted. Move the helpers onto ChatService as static
methods. No behavior change, tests now exercise them through ChatService.

* docs: document the SSE replay buffer in server README-dev

Add the resumable streaming section, list stream_session_manager in the
backend component inventory, and link PR 23226 in the related PRs.

* ui: align attachServerStream call with onCompletionId param in handleStreamResponse

* server-http: rename del_ to del to match get and post

* ui: address review feedback from allozaur

* ui: drop duplicate SSE constants, keep sse.ts canonical

* ui: use svelte:document for the visibilitychange listener

address review from allozaur: replace the manual document.addEventListener
in onMount with a declarative <svelte:document onvisibilitychange>. svelte
handles attach, detach and SSR, so the typeof document guard and the onMount
cleanup go away. onMount keeps only the first load snapshot.

* server: trim redundant stream drain comments

Address review from ngxson

* server: balance and clean up stream comments

remove redundant comments and tighten the verbose ones across the resumable
stream code, keeping the concurrency and lifetime rationale that is not obvious
from the code. also fix two stale comments in server.cpp and server-models.h
that still described the old ::model suffix probe and fan out routing, now
replaced by the conv_id -> model map

Address review from ngxson

* ui: balance and clean up stream comments

dedup repeated rationale (frozen conv::model identity, the lookup privacy note,
the abort patterns) down to one canonical spot, tighten the verbose blocks, and
keep the concurrency and resume-offset reasoning. fix stale comments in
stream-identity.ts and chat.service.ts that still described the old loopback
probe and fan out routing, now the conv_id -> model map.

---------

Co-authored-by: Xuan Son Nguyen <son@huggingface.co>
2026-06-26 09:31:29 +02:00
2026-06-25 17:23:37 +02:00
2026-06-12 15:53:26 +02:00
2026-02-02 08:51:25 +02:00
2026-02-02 08:38:55 +02:00

llama.cpp

llama

License: MIT Release Server Docker Winget

Manifesto / ggml / ops

LLM inference in C/C++

Recent API changes

Hot topics


Quick start

Getting started with llama.cpp is straightforward. Here are several ways to install it on your machine:

Once installed, you'll need a model to work with. Head to the Obtaining and quantizing models section to learn more.

Example command:

# Use a local model file
llama-cli -m my_model.gguf

# Or download and run a model directly from Hugging Face
llama-cli -hf ggml-org/gemma-3-1b-it-GGUF

# Launch OpenAI-compatible API server
llama-server -hf ggml-org/gemma-3-1b-it-GGUF

Description

The main goal of llama.cpp is to enable LLM inference with minimal setup and state-of-the-art performance on a wide range of hardware - locally and in the cloud.

  • Plain C/C++ implementation without any dependencies
  • Apple silicon is a first-class citizen - optimized via ARM NEON, Accelerate and Metal frameworks
  • AVX, AVX2, AVX512 and AMX support for x86 architectures
  • RVV, ZVFH, ZFH, ZICBOP and ZIHINTPAUSE support for RISC-V architectures
  • 1.5-bit, 2-bit, 3-bit, 4-bit, 5-bit, 6-bit, and 8-bit integer quantization for faster inference and reduced memory use
  • Custom CUDA kernels for running LLMs on NVIDIA GPUs (support for AMD GPUs via HIP and Moore Threads GPUs via MUSA)
  • Vulkan and SYCL backend support
  • CPU+GPU hybrid inference to partially accelerate models larger than the total VRAM capacity

The llama.cpp project is the main playground for developing new features for the ggml library.

Models

Typically finetunes of the base models below are supported as well.

Instructions for adding support for new models: HOWTO-add-model.md

Text-only

Multimodal

Bindings
UIs

(to have a project listed here, it should clearly state that it depends on llama.cpp)

Tools
  • akx/ggify download PyTorch models from Hugging Face Hub and convert them to GGML
  • akx/ollama-dl download models from the Ollama library to be used directly with llama.cpp
  • crashr/gppm launch llama.cpp instances utilizing NVIDIA Tesla P40 or P100 GPUs with reduced idle power consumption
  • gpustack/gguf-parser - review/check the GGUF file and estimate the memory usage
  • Styled Lines (proprietary licensed, async wrapper of inference part for game development in Unity3d with pre-built Mobile and Web platform wrappers and a model example)
  • unslothai/unsloth 🦥 exports/saves fine-tuned and trained models to GGUF (Apache-2.0)
Infrastructure
  • Paddler - Open-source LLMOps platform for hosting and scaling AI in your own infrastructure
  • GPUStack - Manage GPU clusters for running LLMs
  • llama_cpp_canister - llama.cpp as a smart contract on the Internet Computer, using WebAssembly
  • llama-swap - transparent proxy that adds automatic model switching with llama-server
  • Kalavai - Crowdsource end to end LLM deployment at any scale
  • llmaz - ☸️ Easy, advanced inference platform for large language models on Kubernetes.
  • LLMKube - Kubernetes operator for llama.cpp with multi-GPU and Apple Silicon Metal support"
Games
  • Lucy's Labyrinth - A simple maze game where agents controlled by an AI model will try to trick you.

Supported backends

Backend Target devices
Metal Apple Silicon
BLAS All
BLIS All
SYCL Intel GPU
OpenVINO [In Progress] Intel CPUs, GPUs, and NPUs
MUSA Moore Threads GPU
CUDA Nvidia GPU
HIP AMD GPU
ZenDNN AMD CPU
Vulkan GPU
CANN Ascend NPU
OpenCL Adreno GPU
IBM zDNN IBM Z & LinuxONE
WebGPU All
RPC All
Hexagon [In Progress] Snapdragon
VirtGPU VirtGPU APIR

Obtaining and quantizing models

The Hugging Face platform hosts a number of LLMs compatible with llama.cpp:

You can either manually download the GGUF file or directly use any llama.cpp-compatible models from Hugging Face or other model hosting sites, by using this CLI argument: -hf <user>/<model>[:quant]. For example:

llama-cli -hf ggml-org/gemma-3-1b-it-GGUF

By default, the CLI would download from Hugging Face, you can switch to other options with the environment variable MODEL_ENDPOINT. The MODEL_ENDPOINT must point to a Hugging Face compatible API endpoint.

After downloading a model, use the CLI tools to run it locally - see below.

llama.cpp requires the model to be stored in the GGUF file format. Models in other data formats can be converted to GGUF using the convert_*.py Python scripts in this repo.

The Hugging Face platform provides a variety of online tools for converting, quantizing and hosting models with llama.cpp:

To learn more about model quantization, read this documentation

llama-cli

A CLI tool for accessing and experimenting with most of llama.cpp's functionality.

  • Run in conversation mode

    Models with a built-in chat template will automatically activate conversation mode. If this doesn't occur, you can manually enable it by adding -cnv and specifying a suitable chat template with --chat-template NAME

    llama-cli -m model.gguf
    
    # > hi, who are you?
    # Hi there! I'm your helpful assistant! I'm an AI-powered chatbot designed to assist and provide information to users like you. I'm here to help answer your questions, provide guidance, and offer support on a wide range of topics. I'm a friendly and knowledgeable AI, and I'm always happy to help with anything you need. What's on your mind, and how can I assist you today?
    #
    # > what is 1+1?
    # Easy peasy! The answer to 1+1 is... 2!
    
  • Run in conversation mode with custom chat template
    # use the "chatml" template (use -h to see the list of supported templates)
    llama-cli -m model.gguf -cnv --chat-template chatml
    
    # use a custom template
    llama-cli -m model.gguf -cnv --in-prefix 'User: ' --reverse-prompt 'User:'
    
  • Constrain the output with a custom grammar
    llama-cli -m model.gguf -n 256 --grammar-file grammars/json.gbnf -p 'Request: schedule a call at 8pm; Command:'
    
    # {"appointmentTime": "8pm", "appointmentDetails": "schedule a a call"}
    

    The grammars/ folder contains a handful of sample grammars. To write your own, check out the GBNF Guide.

    For authoring more complex JSON grammars, check out https://grammar.intrinsiclabs.ai/

llama-server

A lightweight, OpenAI API compatible, HTTP server for serving LLMs.

  • Start a local HTTP server with default configuration on port 8080
    llama-server -m model.gguf --port 8080
    
    # Basic web UI can be accessed via browser: http://localhost:8080
    # Chat completion endpoint: http://localhost:8080/v1/chat/completions
    
  • Support multiple-users and parallel decoding
    # up to 4 concurrent requests, each with 4096 max context
    llama-server -m model.gguf -c 16384 -np 4
    
  • Enable speculative decoding
    # the draft.gguf model should be a small variant of the target model.gguf
    llama-server -m model.gguf -md draft.gguf
    
  • Serve an embedding model
    # use the /embedding endpoint
    llama-server -m model.gguf --embedding --pooling cls -ub 8192
    
  • Serve a reranking model
    # use the /reranking endpoint
    llama-server -m model.gguf --reranking
    
  • Constrain all outputs with a grammar
    # custom grammar
    llama-server -m model.gguf --grammar-file grammar.gbnf
    
    # JSON
    llama-server -m model.gguf --grammar-file grammars/json.gbnf
    

llama-perplexity

A tool for measuring the perplexity 1 (and other quality metrics) of a model over a given text.

  • Measure the perplexity over a text file
    llama-perplexity -m model.gguf -f file.txt
    
    # [1]15.2701,[2]5.4007,[3]5.3073,[4]6.2965,[5]5.8940,[6]5.6096,[7]5.7942,[8]4.9297, ...
    # Final estimate: PPL = 5.4007 +/- 0.67339
    
  • Measure KL divergence
    # TODO
    

llama-bench

Benchmark the performance of the inference for various parameters.

  • Run default benchmark
    llama-bench -m model.gguf
    
    # Output:
    # | model               |       size |     params | backend    | threads |          test |                  t/s |
    # | ------------------- | ---------: | ---------: | ---------- | ------: | ------------: | -------------------: |
    # | qwen2 1.5B Q4_0     | 885.97 MiB |     1.54 B | Metal,BLAS |      16 |         pp512 |      5765.41 ± 20.55 |
    # | qwen2 1.5B Q4_0     | 885.97 MiB |     1.54 B | Metal,BLAS |      16 |         tg128 |        197.71 ± 0.81 |
    #
    # build: 3e0ba0e60 (4229)
    

llama-simple

A minimal example for implementing apps with llama.cpp. Useful for developers.

  • Basic text completion
    llama-simple -m model.gguf
    
    # Hello my name is Kaitlyn and I am a 16 year old girl. I am a junior in high school and I am currently taking a class called "The Art of
    

Contributing

  • Contributors can open PRs
  • Collaborators will be invited based on contributions
  • Maintainers can push to branches in the llama.cpp repo and merge PRs into the master branch
  • Any help with managing issues, PRs and projects is very appreciated!
  • See good first issues for tasks suitable for first contributions
  • Read the CONTRIBUTING.md for more information
  • Make sure to read this: Inference at the edge
  • A bit of backstory for those who are interested: Changelog podcast

Other documentation

Development documentation

Seminal papers and background on the models

If your issue is with model generation quality, then please at least scan the following links and papers to understand the limitations of LLaMA models. This is especially important when choosing an appropriate model size and appreciating both the significant and subtle differences between LLaMA models and ChatGPT:

XCFramework

The XCFramework is a precompiled version of the library for iOS, visionOS, tvOS, and macOS. It can be used in Swift projects without the need to compile the library from source. For example:

// swift-tools-version: 5.10
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "MyLlamaPackage",
    targets: [
        .executableTarget(
            name: "MyLlamaPackage",
            dependencies: [
                "LlamaFramework"
            ]),
        .binaryTarget(
            name: "LlamaFramework",
            url: "https://github.com/ggml-org/llama.cpp/releases/download/b5046/llama-b5046-xcframework.zip",
            checksum: "c19be78b5f00d8d29a25da41042cb7afa094cbf6280a225abe614b03b20029ab"
        )
    ]
)

The above example is using an intermediate build b5046 of the library. This can be modified to use a different version by changing the URL and checksum.

Completions

Command-line completion is available for some environments.

Bash Completion

$ build/bin/llama-cli --completion-bash > ~/.llama-completion.bash
$ source ~/.llama-completion.bash

Optionally this can be added to your .bashrc or .bash_profile to load it automatically. For example:

$ echo "source ~/.llama-completion.bash" >> ~/.bashrc

Dependencies

  • yhirose/cpp-httplib - Single-header HTTP server, used by llama-server - MIT license
  • stb-image - Single-header image format decoder, used by multimodal subsystem - Public domain
  • nlohmann/json - Single-header JSON library, used by various tools/examples - MIT License
  • miniaudio.h - Single-header audio format decoder, used by multimodal subsystem - Public domain
  • subprocess.h - Single-header process launching solution for C and C++ - Public domain
Description
Mirror of llama.cpp from github
Readme MIT 1.7 GiB
Languages
C++ 56.9%
C 14.5%
Python 7.5%
Cuda 5.5%
TypeScript 3.7%
Other 11.6%