Quickstart | vLLM Agentic API

Install vLLM Agentic API, connect it to a running vLLM server, and send your first Responses API request. These commands use the 0.9.0 release on PyPI.

Before you start

Use Python 3.10 or newer on Linux x86_64 (glibc 2.17 or newer) or macOS (Intel or Apple Silicon).
Have vLLM serving a tool-capable model through its OpenAI-compatible /v1/responses endpoint at http://127.0.0.1:8000. Configure vLLM's tool-call parser for that model. The first request below does not call a tool. The base agentic-api package includes the Rust gateway and CLI, but does not install vLLM or GPU dependencies.

Check the upstream's model ID before making a request:

curl -sS http://127.0.0.1:8000/v1/models

Use the exact id returned for your model in the request below.

Install the gateway

python -m pip install agentic-api==0.9.0
python -m agentic_api --version
python -m agentic_api doctor --mode remote

The doctor command checks the packaged gateway for this mode. It does not start vLLM.

Start the gateway

In one terminal, run:

python -m agentic_api serve --vllm-base-url http://127.0.0.1:8000

The gateway listens on port 9000 by default. Leave this terminal running for the next step. Pass the upstream's base URL, without /v1.

Send a Responses API request

In another terminal, replace MODEL_ID with the ID returned by the upstream and run:

curl -sS http://127.0.0.1:9000/v1/responses \
  -H 'Content-Type: application/json' \
  -d '{"model":"MODEL_ID","input":"Say hello in one sentence."}'

The JSON response contains an output array. To continue a stored response, see the Responses API reference.

Next steps

For a coding client, install Codex or Claude Code separately and use the packaged agentic CLI's run codex or run claude command. These commands launch a gateway for the client; see the Rust CLI reference and Claude Code guide.
To let the Python launcher manage vLLM on a supported Linux GPU host, install agentic-api[local]==0.9.0 and use python -m agentic_api serve --model MODEL_ID. See Python installation and workflows for the local mode and diagnostics.
If you prefer Cargo, agentic-server on crates.io installs the Rust-native agentic CLI and gateway.