OfflineCreator MCP compatibility with Goose

Compatibility status: documentation and challenge verified, client acceptance pending

Goose has the two client capabilities OfflineCreator needs on paper: current Goose configuration supports remote `streamable_http` extensions, and its connection code can start OAuth after an authentication-required response. OfflineCreator publishes a Streamable HTTP endpoint with OAuth discovery metadata and returned a standards-shaped `401` challenge during this research pass.

That is protocol alignment, not an end-to-end compatibility result. Goose was not installed in the research environment, so this pass did not complete browser consent, inspect Goose's credential store, list OfflineCreator tools in a live session, or call a tool. Keep the setup support-qualified until those steps are reproduced in a dated current Goose build.

Documentation level

Supported path identifiedCurrent Goose documentation and source define the required remote transport and OAuth path.

Protocol level

Unauthenticated challenge verifiedThe live OfflineCreator endpoint returned `401` with `resource_metadata` and the expected scopes.

Client acceptance level

Not testedNo browser authorization, Goose tool listing, or OfflineCreator tool invocation was completed.

Add OfflineCreator as a Streamable HTTP extension

The least ambiguous persistent setup is to run `goose configure`, choose `Add Extension`, and select `Remote Extension (Streamable HTTP)`. Name the extension `offlinecreator`, enter `https://mcp.offlinecreatorstudio.com/mcp`, keep it enabled, and use a reasonable timeout such as 300 seconds.

Advanced users can edit `~/.config/goose/config.yaml`. Current Goose source deserializes entries directly below `extensions`, with `enabled` beside the flattened extension fields. For a remote entry, the exact transport value is `streamable_http` and the endpoint field is `uri`. Do not borrow another client's `mcpServers`, `url`, or `serverUrl` schema.

Interactive path

goose configure → Add Extension → Remote Extension (Streamable HTTP)Use the current Goose-owned configuration flow when possible.

Persistent YAML

extensions: offlinecreator: enabled: true type: streamable_http name: offlinecreator description: OfflineCreator Studio MCP uri: "https://mcp.offlinecreatorstudio.com/mcp" timeout: 300The field names follow the current Goose `ExtensionConfig::StreamableHttp` schema.

One-session check

goose session --with-streamable-http-extension "https://mcp.offlinecreatorstudio.com/mcp"Starts a session with the remote extension without making it a persistent YAML entry.

Let Goose start the OAuth flow

Do not add a static `Authorization` header or put a personal key in the recommended remote URL. Start Goose with the extension enabled and allow its connection attempt to receive the authentication challenge. Current Goose code attempts OAuth for the typed authentication-required response and for an unexpected HTTP `401`; the latter fallback was merged in April 2026.

The live endpoint challenge points Goose at `https://mcp.offlinecreatorstudio.com/.well-known/oauth-protected-resource/mcp` and requests `models read generate`. The linked metadata names the authorization server, and its authorization metadata advertises dynamic client registration, authorization-code and refresh-token grants, public-client token authentication, and S256 PKCE. Those declarations fit Goose's documented OAuth path, but only a completed browser flow proves interoperability for this server.

Recommended endpoint

https://mcp.offlinecreatorstudio.com/mcpUse the exact HTTPS URL, including the `/mcp` path.

Static credentials

None in the recommended configurationAllow remote OAuth discovery rather than embedding a key.

Expected next step

Browser sign-in and consentIf Goose only reports `401`, capture the client version and logs before changing the server URL.

Verify discovery before spending credits

After browser authorization returns to Goose, start a fresh session with the extension enabled and ask Goose to list the tools supplied by `offlinecreator`. Separate three checks in the acceptance record: the extension parsed, OAuth completed, and tools were discovered. A configured entry alone does not prove the other two states.

The published OfflineCreator package currently documents nine MCP tools and says API-key tool visibility is filtered by key scope. That package statement does not establish which tools Goose exposes after an OAuth grant. Begin with a non-generation discovery action such as `list_models`, record the names Goose actually exposes, and do not run a paid generation merely to prove transport compatibility.

Verification prompt

List the tools currently available from the offlinecreator extension.Use the result to confirm Goose's live registry after OAuth.

First safe tool

list_modelsA catalog request is a narrower acceptance check than media generation.

Record

Goose version, operating system, OAuth result, and visible tool namesRemove tokens, browser data, prompts, and account details before sharing diagnostics.

Troubleshoot the Goose boundary

If Goose rejects the YAML before connecting, check the client-owned field names first: `extensions`, `enabled`, `type: streamable_http`, and `uri`. Current Goose source keeps `sse` only for configuration compatibility and rejects it during activation, so do not downgrade the endpoint to SSE.

If the server returns `401` but no browser flow appears, confirm the Goose version. The latest release retrieved for this pass was v1.45.0, published July 29, 2026, and the OAuth fallback fix was merged before that release. Capture the exact error without tokens. If OAuth completes but tools are absent, verify the extension remains enabled, start a new session, and compare the granted scopes with the tool requirements before blaming the endpoint.

Configuration error

Recheck Goose fieldsDo not paste JSON or YAML owned by Cursor, VS Code, Hermes, or another client.

OAuth never starts

Record the Goose version and `401` errorThe current code contains both typed-auth and bare-401 OAuth paths.

No tools after consent

Restart the session and inspect scopesConfiguration, authorization, and discovery are separate checkpoints.

Continue with the next client task

Return to the client directory for another host, compare protocol behavior across clients, or use the connection-verification checklist to turn this documentation-backed setup into a dated Goose acceptance result.

Page boundary

This page owns only the OfflineCreator setup decision for Goose and the evidence needed to qualify that connection. It does not claim universal Goose compatibility, successful authorization, a fixed tool count for every grant, generation success, performance, reliability, or customer outcomes. Keep it as an unreviewed draft until a dated current-client acceptance run closes those gaps.