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Juan Pérez de Algaba add8cd801b
feat(gemini): Support gemini-embedding-001 and fix models/ prefix in metadata keys (#3813)
# Add support for Google Gemini `gemini-embedding-001` embedding model
and correctly registers model type

MR message created with the assistance of Claude-4.5-sonnet

This resolves https://github.com/llamastack/llama-stack/issues/3755

## What does this PR do?

This PR adds support for the `gemini-embedding-001` Google embedding
model to the llama-stack Gemini provider. This model provides
high-dimensional embeddings (3072 dimensions) compared to the existing
`text-embedding-004` model (768 dimensions). Old embeddings models (such
as text-embedding-004) will be deprecated soon according to Google
([Link](https://developers.googleblog.com/en/gemini-embedding-available-gemini-api/))

## Problem

The Gemini provider only supported the `text-embedding-004` embedding
model. The newer `gemini-embedding-001` model, which provides
higher-dimensional embeddings for improved semantic representation, was
not available through llama-stack.

## Solution

This PR consists of three commits that implement, fix the model
registration, and enable embedding generation:

### Commit 1: Initial addition of gemini-embedding-001

Added metadata for `gemini-embedding-001` to the
`embedding_model_metadata` dictionary:

```python
embedding_model_metadata: dict[str, dict[str, int]] = {
    "text-embedding-004": {"embedding_dimension": 768, "context_length": 2048},
    "gemini-embedding-001": {"embedding_dimension": 3072, "context_length": 2048},  # NEW
}
```

**Issue discovered:** The model was not being registered correctly
because the dictionary keys didn't match the model IDs returned by
Gemini's API.

### Commit 2: Fix model ID matching with `models/` prefix

Updated both dictionary keys to include the `models/` prefix to match
Gemini's OpenAI-compatible API response format:

```python
embedding_model_metadata: dict[str, dict[str, int]] = {
    "models/text-embedding-004": {"embedding_dimension": 768, "context_length": 2048},      # UPDATED
    "models/gemini-embedding-001": {"embedding_dimension": 3072, "context_length": 2048},  # UPDATED
}
```

**Root cause:** Gemini's OpenAI-compatible API returns model IDs with
the `models/` prefix (e.g., `models/text-embedding-004`). The
`OpenAIMixin.list_models()` method directly matches these IDs against
the `embedding_model_metadata` dictionary keys. Without the prefix, the
models were being registered as LLMs instead of embedding models.

### Commit 3: Fix embedding generation for providers without usage stats

Fixed a bug in `OpenAIMixin.openai_embeddings()` that prevented
embedding generation for providers (like Gemini) that don't return usage
statistics:

```python
# Before (Line 351-354):
usage = OpenAIEmbeddingUsage(
    prompt_tokens=response.usage.prompt_tokens,  # ← Crashed with AttributeError
    total_tokens=response.usage.total_tokens,
)

# After (Lines 351-362):
if response.usage:
    usage = OpenAIEmbeddingUsage(
        prompt_tokens=response.usage.prompt_tokens,
        total_tokens=response.usage.total_tokens,
    )
else:
    usage = OpenAIEmbeddingUsage(
        prompt_tokens=0,  # Default when not provided
        total_tokens=0,   # Default when not provided
    )
```

**Impact:** This fix enables embedding generation for **all** Gemini
embedding models, not just the newly added one.

## Changes

### Modified Files

**`llama_stack/providers/remote/inference/gemini/gemini.py`**
- Line 17: Updated `text-embedding-004` key to
`models/text-embedding-004`
- Line 18: Added `models/gemini-embedding-001` with correct metadata

**`llama_stack/providers/utils/inference/openai_mixin.py`**
- Lines 351-362: Added null check for `response.usage` to handle
providers without usage statistics

## Key Technical Details

### Model ID Matching Flow

1. `list_provider_model_ids()` calls Gemini's `/v1/models` endpoint
2. API returns model IDs like: `models/text-embedding-004`,
`models/gemini-embedding-001`
3. `OpenAIMixin.list_models()` (line 410) checks: `if metadata :=
self.embedding_model_metadata.get(provider_model_id)`
4. If matched, registers as `model_type: "embedding"` with metadata;
otherwise registers as `model_type: "llm"`

### Why Both Keys Needed the Prefix

The `text-embedding-004` model was already working because there was
likely separate configuration or manual registration handling it. For
auto-discovery to work correctly for **both** models, both keys must
match the API's model ID format exactly.

## How to test this PR

Verified the changes by:

1. **Model Auto-Discovery**: Started llama-stack server and confirmed
models are auto-discovered from Gemini API

2. **Model Registration**: Confirmed both embedding models are correctly
registered and visible
```bash
curl http://localhost:8325/v1/models | jq '.data[] | select(.provider_id == "gemini" and .model_type == "embedding")'
```

**Results:**
-  `gemini/models/text-embedding-004` - 768 dimensions - `model_type:
"embedding"`
-  `gemini/models/gemini-embedding-001` - 3072 dimensions -
`model_type: "embedding"`

3. **Before Fix (Commit 1)**: Models appeared as `model_type: "llm"`
without embedding metadata

4. **After Fix (Commit 2)**: Models correctly identified as `model_type:
"embedding"` with proper metadata

5. **Generate Embeddings**: Verified embedding generation works
```bash
curl -X POST http://localhost:8325/v1/embeddings \
  -H "Content-Type: application/json" \
  -d '{"model": "gemini/models/gemini-embedding-001", "input": "test"}' | \
  jq '.data[0].embedding | length'
```
2025-10-15 12:22:10 -04:00
.github refactor: replace default all-MiniLM-L6-v2 embedding model by nomic-embed-text-v1.5 in Llama Stack (#3183) 2025-10-14 10:44:20 -04:00
benchmarking/k8s-benchmark refactor: replace default all-MiniLM-L6-v2 embedding model by nomic-embed-text-v1.5 in Llama Stack (#3183) 2025-10-14 10:44:20 -04:00
docs feat: Enable setting a default embedding model in the stack (#3803) 2025-10-14 18:25:13 -07:00
llama_stack feat(gemini): Support gemini-embedding-001 and fix models/ prefix in metadata keys (#3813) 2025-10-15 12:22:10 -04:00
scripts refactor: replace default all-MiniLM-L6-v2 embedding model by nomic-embed-text-v1.5 in Llama Stack (#3183) 2025-10-14 10:44:20 -04:00
tests chore: Support embedding params from metadata for Vector Store (#3811) 2025-10-15 15:53:36 +02:00
.coveragerc test: Measure and track code coverage (#2636) 2025-07-18 18:08:36 +02:00
.gitignore docs: docusaurus setup (#3541) 2025-09-24 14:11:30 -07:00
.pre-commit-config.yaml fix: distro-codegen pre-commit hook file pattern (#3337) 2025-09-04 17:56:32 +02:00
CHANGELOG.md docs: Update changelog (#3343) 2025-09-08 10:01:41 +02:00
CODE_OF_CONDUCT.md Initial commit 2024-07-23 08:32:33 -07:00
CONTRIBUTING.md docs: Update CONTRIBUTING: py 3.12 and pre-commit==4.3.0 (#3807) 2025-10-14 15:47:38 -04:00
coverage.svg test: Measure and track code coverage (#2636) 2025-07-18 18:08:36 +02:00
LICENSE Update LICENSE (#47) 2024-08-29 07:39:50 -07:00
MANIFEST.in chore: MANIFEST maintenance (#3454) 2025-09-27 11:28:11 -07:00
pyproject.toml fix: replace python-jose with PyJWT for JWT handling (#3756) 2025-10-14 09:35:48 +02:00
README.md chore!: remove model mgmt from CLI for Hugging Face CLI (#3700) 2025-10-09 16:50:33 -07:00
SECURITY.md Create SECURITY.md 2024-10-08 13:30:40 -04:00
uv.lock fix: replace python-jose with PyJWT for JWT handling (#3756) 2025-10-14 09:35:48 +02:00

Llama Stack

PyPI version PyPI - Downloads License Discord Unit Tests Integration Tests

Quick Start | Documentation | Colab Notebook | Discord

🎉 Llama 4 Support 🎉

We released Version 0.2.0 with support for the Llama 4 herd of models released by Meta.

👋 Click here to see how to run Llama 4 models on Llama Stack


Note you need 8xH100 GPU-host to run these models

pip install -U llama_stack

MODEL="Llama-4-Scout-17B-16E-Instruct"
# get meta url from llama.com
huggingface-cli download meta-llama/$MODEL --local-dir ~/.llama/$MODEL

# start a llama stack server
INFERENCE_MODEL=meta-llama/$MODEL llama stack build --run --template meta-reference-gpu

# install client to interact with the server
pip install llama-stack-client

CLI

# Run a chat completion
MODEL="Llama-4-Scout-17B-16E-Instruct"

llama-stack-client --endpoint http://localhost:8321 \
inference chat-completion \
--model-id meta-llama/$MODEL \
--message "write a haiku for meta's llama 4 models"

OpenAIChatCompletion(
    ...
    choices=[
        OpenAIChatCompletionChoice(
            finish_reason='stop',
            index=0,
            message=OpenAIChatCompletionChoiceMessageOpenAIAssistantMessageParam(
                role='assistant',
                content='...**Silent minds awaken,**  \n**Whispers of billions of words,**  \n**Reasoning breaks the night.**  \n\n—  \n*This haiku blends the essence of LLaMA 4\'s capabilities with nature-inspired metaphor, evoking its vast training data and transformative potential.*',
                ...
            ),
            ...
        )
    ],
    ...
)

Python SDK

from llama_stack_client import LlamaStackClient

client = LlamaStackClient(base_url=f"http://localhost:8321")

model_id = "meta-llama/Llama-4-Scout-17B-16E-Instruct"
prompt = "Write a haiku about coding"

print(f"User> {prompt}")
response = client.chat.completions.create(
    model=model_id,
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": prompt},
    ],
)
print(f"Assistant> {response.choices[0].message.content}")

As more providers start supporting Llama 4, you can use them in Llama Stack as well. We are adding to the list. Stay tuned!

🚀 One-Line Installer 🚀

To try Llama Stack locally, run:

curl -LsSf https://github.com/meta-llama/llama-stack/raw/main/scripts/install.sh | bash

Overview

Llama Stack standardizes the core building blocks that simplify AI application development. It codifies best practices across the Llama ecosystem. More specifically, it provides

  • Unified API layer for Inference, RAG, Agents, Tools, Safety, Evals, and Telemetry.
  • Plugin architecture to support the rich ecosystem of different API implementations in various environments, including local development, on-premises, cloud, and mobile.
  • Prepackaged verified distributions which offer a one-stop solution for developers to get started quickly and reliably in any environment.
  • Multiple developer interfaces like CLI and SDKs for Python, Typescript, iOS, and Android.
  • Standalone applications as examples for how to build production-grade AI applications with Llama Stack.
Llama Stack

Llama Stack Benefits

  • Flexible Options: Developers can choose their preferred infrastructure without changing APIs and enjoy flexible deployment choices.
  • Consistent Experience: With its unified APIs, Llama Stack makes it easier to build, test, and deploy AI applications with consistent application behavior.
  • Robust Ecosystem: Llama Stack is already integrated with distribution partners (cloud providers, hardware vendors, and AI-focused companies) that offer tailored infrastructure, software, and services for deploying Llama models.

By reducing friction and complexity, Llama Stack empowers developers to focus on what they do best: building transformative generative AI applications.

API Providers

Here is a list of the various API providers and available distributions that can help developers get started easily with Llama Stack. Please checkout for full list

API Provider Builder Environments Agents Inference VectorIO Safety Telemetry Post Training Eval DatasetIO
Meta Reference Single Node
SambaNova Hosted
Cerebras Hosted
Fireworks Hosted
AWS Bedrock Hosted
Together Hosted
Groq Hosted
Ollama Single Node
TGI Hosted/Single Node
NVIDIA NIM Hosted/Single Node
ChromaDB Hosted/Single Node
Milvus Hosted/Single Node
Qdrant Hosted/Single Node
Weaviate Hosted/Single Node
SQLite-vec Single Node
PG Vector Single Node
PyTorch ExecuTorch On-device iOS
vLLM Single Node
OpenAI Hosted
Anthropic Hosted
Gemini Hosted
WatsonX Hosted
HuggingFace Single Node
TorchTune Single Node
NVIDIA NEMO Hosted
NVIDIA Hosted

Note

: Additional providers are available through external packages. See External Providers documentation.

Distributions

A Llama Stack Distribution (or "distro") is a pre-configured bundle of provider implementations for each API component. Distributions make it easy to get started with a specific deployment scenario - you can begin with a local development setup (eg. ollama) and seamlessly transition to production (eg. Fireworks) without changing your application code. Here are some of the distributions we support:

Distribution Llama Stack Docker Start This Distribution
Starter Distribution llamastack/distribution-starter Guide
Meta Reference llamastack/distribution-meta-reference-gpu Guide
PostgreSQL llamastack/distribution-postgres-demo

Documentation

Please checkout our Documentation page for more details.

Llama Stack Client SDKs

Language Client SDK Package
Python llama-stack-client-python PyPI version
Swift llama-stack-client-swift Swift Package Index
Typescript llama-stack-client-typescript NPM version
Kotlin llama-stack-client-kotlin Maven version

Check out our client SDKs for connecting to a Llama Stack server in your preferred language, you can choose from python, typescript, swift, and kotlin programming languages to quickly build your applications.

You can find more example scripts with client SDKs to talk with the Llama Stack server in our llama-stack-apps repo.

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Contributors

Thanks to all of our amazing contributors!