Context Bundles

A context bundle is the resolved runtime identity for a DCC MCP session. It answers: which production domain is this, what kind of work is being done, which project/shot/asset is active, and which skill packages should be visible?

Rez context -> env vars -> DCC startup -> skill scan -> gateway metadata -> context-aware tools/list

dcc-mcp-core reads this resolved environment. It does not choose packages, solve versions, or replace a studio package manager.

Runtime Flow

1. Rez resolves packages for a project, department, task, asset type, and DCC.
2. The package commands set DCC_MCP_* context and path variables.
3. The DCC adapter starts DccServerBase or McpHttpServer.
4. Skills are discovered from DCC_MCP_SKILL_PATHS and DCC_MCP_<DCC>_SKILL_PATHS.
5. The gateway records context metadata in FileRegistry.
6. Clients read the gateway://instances MCP resource (or search_skills / load_skill) against the selected context instead of exposing every studio tool at once.

Metadata Keys

The gateway returns context metadata under each instance's metadata field. The built-in DccServerBase populates these keys from environment variables:

Metadata key	Environment variable
context_bundle	DCC_MCP_CONTEXT_BUNDLE
production_domain	DCC_MCP_PRODUCTION_DOMAIN
context_kind	DCC_MCP_CONTEXT_KIND
project	DCC_MCP_PROJECT
sequence	DCC_MCP_SEQUENCE
shot	DCC_MCP_SHOT
asset	DCC_MCP_ASSET
asset_type	DCC_MCP_ASSET_TYPE
task	DCC_MCP_TASK
toolset_profile	DCC_MCP_TOOLSET_PROFILE
package_provenance	DCC_MCP_PACKAGE_PROVENANCE
skill_paths	DCC_MCP_SKILL_PATHS
dcc_skill_paths	DCC_MCP_<DCC>_SKILL_PATHS

Adapters that do not use DccServerBase can set the same values explicitly via McpHttpConfig.instance_metadata.

Gateway Routing

The gateway is intentionally a selector over already-launched contexts. It should not multiply every backend tool into one massive global surface. A client should first read the gateway://instances MCP resource, choose a matching bundle or DCC session, and then load/search skills in that selected context.

Example selection criteria:

• production_domain=film, context_kind=shot, task=animation -> Maya animation blocking tools.
• production_domain=film, context_kind=shot, task=fx -> Houdini cache and sim review tools.
• production_domain=game, context_kind=level -> level-layout tools.

Examples

Copyable manifests live under examples/context-bundles/. Example Rez skill packages live under examples/rez-skills/; each package has a package.py, SKILL.md, tools.yaml, README.md, and a tiny script.

For package layout and provenance guidance, see rez-skill-packages.md.