---
title: "Authentication and API access"
description: "Create a scoped API key, authenticate requests, or connect an MCP client."
canonical: "https://www.hedra.com/docs/pages/developer/v3/authentication"
---

# Authentication and API access

[View on Hedra](https://www.hedra.com/docs/pages/developer/v3/authentication)

## Start without credentials

Browse the [public model catalog](https://api.hedra.com/v3/models) and inspect model contracts before submitting a job.

## Create an API key

Sign in to the [API keys page](https://www.hedra.com/develop/api-keys) to create and manage keys. Choose the scopes needed by your integration. Language-model calls require `chat:write`.

The credential has the form `<key_id>:<secret>`. Keep long-lived keys server-side, stored as `HEDRA_API_KEY`; do not embed them in browser code. For direct HTTP requests, use:

`Authorization: Key <key_id>:<secret>`

The API also accepts Bearer credentials. Hedra SDKs and OpenAI-compatible clients use Bearer authentication. For OpenAI-compatible clients, use `https://api.hedra.com/v3` as the base URL.

## Permissions and errors

API keys support least-privilege scopes. Choose the permissions required by the endpoints you call. A `401` indicates invalid or missing credentials. A `403` can indicate a missing scope or unavailable workspace access. Consult the [authentication guide](https://www.hedra.com/docs/pages/developer/v3/authentication.md) and [OpenAPI contract](https://www.hedra.com/openapi.json).

For ephemeral browser access, use a token minted through `POST /v3/tokens` and inspect its scopes, workspace and expiry.

## Connect with MCP

Add `https://mcp.hedra.com` to an MCP client and complete Hedra sign-in. MCP does not require pasting an API key into the assistant. Confirm the selected workspace and billing mode in [MCP settings](https://www.hedra.com/develop/mcp).

Read the [MCP setup guide](https://www.hedra.com/docs/pages/developer/v3/mcp.md). Start by listing models and inspecting inputs before submitting a job.

## Billing and availability

REST API and CLI usage use a prepaid USD API wallet, separate from Play subscription credits. MCP uses the billing mode selected in the connection settings. See the [pricing guide](https://www.hedra.com/pricing.md) and [API billing documentation](https://www.hedra.com/docs/pages/developer/v3/billing.md).

Training and GPU Sandboxes are research previews. Dedicated or custom deployments have separate onboarding. See [platform and availability](https://www.hedra.com/docs/pages/developer/v3/platform.md).