NousResearch/hermes-agent · error · ImportError

httpx is required for Entra ID bearer auth on Microsoft Foun

Error message

httpx is required for Entra ID bearer auth on Microsoft Foundry Anthropic-style endpoints. It is normally a transitive dependency of the openai/anthropic SDKs.

What it means

build_bearer_http_client() needs httpx to construct the per-request Authorization-injecting client for Foundry Anthropic-style endpoints. httpx is expected as a transitive dependency of the openai/anthropic SDKs; its absence means the environment is unusually stripped (the code even marks the branch 'pragma: no cover').

Source

Thrown at agent/azure_identity_adapter.py:517

    typically the result of :func:`build_token_provider`.

    ``httpx_kwargs`` are forwarded verbatim to ``httpx.Client(...)`` so
    callers can attach a ``timeout``, ``transport``, ``proxy``, etc.

    Raises ``ImportError`` if ``httpx`` is not installed (it is a
    transitive dependency of both ``openai`` and ``anthropic`` SDKs, so
    in practice always available when this helper is reached).
    """
    if not is_token_provider(token_provider):
        raise ValueError(
            "build_bearer_http_client requires a zero-arg callable "
            "token provider"
        )

    try:
        import httpx
    except ImportError as exc:  # pragma: no cover — httpx ships with openai/anthropic
        raise ImportError(
            "httpx is required for Entra ID bearer auth on Microsoft Foundry "
            "Anthropic-style endpoints. It is normally a transitive "
            "dependency of the openai/anthropic SDKs."
        ) from exc

    def _inject_bearer(request: "httpx.Request") -> None:
        try:
            token = materialize_bearer_for_http(token_provider)
        except ValueError as exc:
            # Token provider failed (chain exhausted, token service unreachable,
            # az login expired, etc.). Strip any auth headers the SDK
            # may have set — including our own placeholder sentinel
            # ``entra-id-bearer-via-http-hook`` from
            # ``_build_anthropic_client_with_bearer_hook`` — so the
            # outbound request hits Azure with NO Authorization rather
            # than with the placeholder. Azure returns a clean 401
            # "missing auth" that is easier to diagnose than a 401
            # against the sentinel string, and the sentinel never

View on GitHub (pinned to c896c09c42)

Solutions

1. pip install httpx
2. Reinstall the openai/anthropic SDK so transitives are restored: pip install --force-reinstall anthropic
3. Recreate the venv from the project's lockfile (uv sync / pip install -e '.').

Example fix

pip install httpx

import importlib.util
assert importlib.util.find_spec("httpx") is not None, "httpx missing — pip install httpx"

try:
    client = build_bearer_http_client(provider)
except ImportError as e:
    if "httpx is required" in str(e):
        run("pip install httpx"); client = build_bearer_http_client(provider)

When it happens

Trigger: Selecting Entra bearer auth on a Foundry Anthropic endpoint in an environment where httpx was never installed alongside the SDKs (agent/azure_identity_adapter.py:517).

Common situations: Minimal dependency set where openai/anthropic were vendored without httpx; dependency pruning tools (pip-autoremove) removed it; corrupted venv.

Related errors

• The 'azure-identity' package is required for Azure AI Foundr
• The 'boto3' package is required for the AWS Bedrock provider
• Expected exported session JSON or JSONL
• File is empty
• Failed to initialize OpenAI client: {e}

AI-assisted analysis of NousResearch/hermes-agent@c896c09c42 (2026-08-14). Data as JSON: /api/errors/ac94f7f93014a855. Report an issue: GitHub.