Capabilities

Caplets can wrap MCP servers, OpenAPI specs, Google Discovery APIs, GraphQL endpoints, simple HTTP APIs, curated CLI commands, and shared Markdown Caplet files such as CAPLET.md.

Start with OSV

OSV is public and does not need auth:

npx caplets install spiritledsoftware/caplets osv

With a global install:

caplets install spiritledsoftware/caplets osv

After installation, Code Mode exposes OSV as a typed capability handle instead of a flat set of visible tools.

Add local sources

Examples:

caplets add mcp docs --command npx --arg -y --arg @upstash/context7-mcp
caplets add openapi users --spec ./openapi.json --base-url https://api.example.com
caplets add google-discovery drive --discovery-url https://www.googleapis.com/discovery/v1/apis/drive/v3/rest
caplets add graphql catalog --endpoint-url https://api.example.com/graphql --schema ./schema.graphql
caplets add http status-api --base-url https://api.example.com --action get_status:GET:/status/{service}
caplets add cli repo-tools --repo . --include git,gh,package

Google Discovery Caplets use Google’s Discovery documents directly. They can infer request base URLs and OAuth scopes from the final exposed operation set, so narrow broad APIs with includeOperations and excludeOperations when a capability only needs a subset.

Inspect from the CLI:

caplets list
caplets inspect osv
caplets search-tools osv vulnerability
caplets get-tool osv query_package_version
caplets call-tool osv query_package_version --args '{"ecosystem":"npm","name":"react","version":"18.2.0"}'

Capability shape

Good Caplets are narrow and named by the job they help an agent do. Prefer a few focused capabilities over one broad catch-all backend.

HTTP-like Caplets return small JSON and text inline. Binary downloads, Google media downloads, and oversized responses are returned as media artifact metadata with local paths or artifact references that agents can pass into later upload calls.

Use Configuration when a capability should be shared through .caplets/config.json.