hermes-yandex-search-api

Give your Hermes Agent first-class Yandex search. This plugin wires the Yandex Search API into Hermes as a drop-in web-search backend and adds a grounded-answer tool — excellent results for Russian-language queries, on infrastructure you may already have in Yandex Cloud.

• 🔎 yandex web-search backend — routes Hermes' built-in web_search tool to Yandex web search (links with titles and snippets). Nothing new for the model to learn.
• 💬 yandex_generative_search tool — a single grounded answer synthesised from live web sources, with the source URLs it cites.

Quick start

# 1. Install into Hermes (alternatively: pip install hermes-yandex-search-api)
hermes plugins install akinfold/hermes-yandex-search-api --enable

# 2. Add your Yandex Cloud credentials (see "Getting a token" below)
printf 'YANDEX_API_KEY=%s\nYANDEX_FOLDER_ID=%s\n' 'your-api-key' 'your-folder-id' >> ~/.hermes/.env

Then select Yandex as the web-search backend in ~/.hermes/config.yaml:

web:
  search_backend: yandex
plugins:
  enabled:
    - yandex

That's it — web_search now goes through Yandex, and the yandex_generative_search tool is available to the agent. Don't have an API key and folder id yet? See Getting a Yandex Search API token. Prefer a drop-in or pip install? See Installing the plugin into Hermes.

Why these two search modes

The Yandex Search API offers several modes — classic web search, generative search, image search, deferred (async) web search, and Wordstat keyword statistics. This plugin deliberately wires up the two that fit an autonomous agent, each in the shape Hermes expects:

• Web search → a web_search backend. Hermes already ships a web_search tool whose backend returns a list of {title, url, description} results. The classic Yandex web search maps onto that contract exactly, so the model can use the search tool it already knows without learning a new one.
• Generative search → its own tool. Generative search returns a synthesised answer with citations, not a list of links. That is a fundamentally different result shape, so it is exposed as a distinct yandex_generative_search tool. It is the best fit when the agent wants a direct, grounded answer to a factual question.

The other modes are intentionally left out: image search returns image URLs an agent cannot usefully consume, Wordstat is SEO keyword analytics unrelated to agentic search, and deferred web search has a multi-minute latency that is unusable for interactive turns. All of them can be added later on top of the same YandexSearchClient if a use case appears.

About the Yandex Search API

The Yandex Search API is Yandex Cloud's paid programmatic access to Yandex web search and its generative answer engine. Requests are authenticated with a Yandex Cloud API key and are billed to the Yandex Cloud folder that owns the key. Both search modes used here run synchronously:

• POST /v2/web/search returns Base64-encoded XML search results.
• POST /v2/gen/search returns a JSON grounded answer with cited sources.

See the pricing and quotas pages for current limits (roughly 10k web requests/hour and 1k generative requests/hour by default).

Requirements

• Hermes Agent >= 0.19 (tested against 0.19.x).
• Python >= 3.11, < 3.14.
• A Yandex Cloud account with the Search API enabled, an API key, and the folder id that owns it.

Getting a Yandex Search API token

1. Create or open a Yandex Cloud account and a folder (catalog). Note its folder id — you can copy it from the console URL or with the CLI: how to get the folder id.
2. Create a service account in that folder and grant it the search-api.webSearch.user role.
3. Create an API key for that service account (Console → the service account → API keys → Create API key), or via CLI:

   yc iam api-key create --service-account-name <sa-name> --format json
   

   Copy the secret value — this is your YANDEX_API_KEY.
4. Make sure the Search API is enabled for the folder and that billing is active.

You now have the two values the plugin needs: YANDEX_API_KEY and YANDEX_FOLDER_ID.

Installing the plugin into Hermes

Option A — install from Git (recommended)

hermes plugins install akinfold/hermes-yandex-search-api --enable

Option B — drop-in directory

Copy the plugin directory into your Hermes plugins folder under the web category, then enable it:

mkdir -p ~/.hermes/plugins/web
cp -r hermes_yandex_search ~/.hermes/plugins/web/yandex
hermes plugins enable yandex

(Or download hermes-yandex-search-plugin-<version>.zip from a GitHub Release and unzip it into ~/.hermes/plugins/web/.)

Option C — pip

pip install hermes-yandex-search-api
hermes plugins enable yandex

Hermes discovers the plugin through the hermes_agent.plugins entry point.

Configuring the token in Hermes

The plugin reads its credentials from the environment, resolved the way every Hermes web backend resolves them: os.environ first, then ~/.hermes/.env. The simplest, persistent option is to put them in ~/.hermes/.env:

YANDEX_API_KEY=your-api-key
YANDEX_FOLDER_ID=your-folder-id
# Optional: market/domain, default SEARCH_TYPE_RU.
# One of SEARCH_TYPE_RU | SEARCH_TYPE_COM | SEARCH_TYPE_TR | SEARCH_TYPE_KK | SEARCH_TYPE_BE | SEARCH_TYPE_UZ
YANDEX_SEARCH_TYPE=SEARCH_TYPE_RU
# Optional: override the API base URL (for a private gateway / testing).
# YANDEX_SEARCH_API_URL=https://searchapi.api.cloud.yandex.net

hermes plugins install ... --enable will also prompt for the values declared in the plugin manifest (YANDEX_API_KEY, YANDEX_FOLDER_ID) during installation.

Selecting Yandex as the web-search backend

To route Hermes' built-in web_search tool to Yandex, set the backend in ~/.hermes/config.yaml:

web:
  search_backend: yandex
plugins:
  enabled:
    - yandex

The yandex_generative_search tool becomes available as soon as the plugin is enabled — no extra configuration needed.

Configuration reference

Development

python -m venv .venv && source .venv/bin/activate
pip install -e '.[dev]'

ruff check .          # lint
ruff format --check . # code style
pytest                # unit tests (live E2E tests are deselected by default)

The package layout separates a Hermes-independent API client from the host integration:

• hermes_yandex_search/client.py — the YandexSearchClient (pure HTTP + parsing, no Hermes imports).
• hermes_yandex_search/provider.py — the yandex web-search backend provider.
• hermes_yandex_search/generative.py — the yandex_generative_search tool.
• hermes_yandex_search/config.py — builds a client from environment variables.
• hermes_yandex_search/__init__.py — register(ctx), the plugin entry point.

Running the live E2E tests

The E2E suite (marked e2e, deselected by default) hits the live Yandex Search API and, when hermes-agent is installed, a live Hermes host.

Locally

Store your API key in a file (created with restrictive permissions), and the folder id in a companion file:

umask 077 && printf '%s' 'your-yandex-search-api-key' > ~/.yandex-search-api-key
umask 077 && printf '%s' 'your-yandex-folder-id'      > ~/.yandex-folder-id

(Alternatively, export YANDEX_API_KEY and YANDEX_FOLDER_ID in your shell — environment variables take precedence over the files.) Then:

pytest -m e2e -v

The Hermes-host test (tests/e2e/test_live_hermes.py) skips automatically unless hermes-agent is importable; install it with pip install hermes-agent to run it.

On GitHub Actions

The E2E (live) workflow (.github/workflows/e2e.yml) is manual (Actions → E2E (live) → Run workflow). It reads credentials from a GitHub Environment so they are never committed to the repo.

If you fork this repository and want to run the live E2E workflow, set up the Environment once:

1. Open Settings → Environments → New environment and name it yandex-e2e (the name the workflow references).
2. Under that environment, add two secrets:
   • YANDEX_API_KEY — your Yandex Cloud API key.
   • YANDEX_FOLDER_ID — your Yandex Cloud folder id.
3. Optionally add an environment variable YANDEX_SEARCH_TYPE (e.g. SEARCH_TYPE_COM) to change the default market. You can also override it per-run via the workflow input.
4. (Recommended) Add required reviewers to the environment so live runs must be approved — this gates access to the paid API.
5. Run the workflow from the Actions tab.

Contributing

Contributions are welcome — see CONTRIBUTING.md for the dev setup and checks to run.

License

MIT © Roman Akinfeev