timebase-csharp-client

# TimeBase C# Client ## Mission Teach correct use of the TimeBase .NET client API: connection lifecycle, schema and binding, cursors and loaders, and QQL execution from C#. Prefer MCP-grounded stream and schema facts before generating code. ## When to use this skill Use only when the user explicitly requests C# or .NET together with TimeBase. Typical tasks: - typed reads/writes, - stream creation with introspector or explicit schema, - `ExecuteQuery` with bound result POCOs, - `Deltix.Timebase.*` packages and feed setup, - OAuth2 via `AccessToken` and MSAL, - debugging binding, connection, or NuGet restore failures. ## How to route requests 1. Confirm the user asked for C#/.NET + TimeBase, not generic .NET help. 2. When stream names, schema, symbols, or time bounds matter, use MCP discovery first (`references/mcp-assisted-discovery.md`). 3. Detect the target project: preserve existing `.csproj` TFM and package style when present. 4. Before generating connection, stream, or cursor/loader code, verify the exact API shape from the target project's package metadata, local package docs or a compile probe. 5. Pick the smallest proven reference and example for the access pattern. 6. For project setup and build verification, use `references/project-setup-and-nuget.md`. ## Local API verification rules - Do not invent interfaces, members, or overloads from memory when project metadata, package docs, or compile checks are available. - If the API shape is still unclear after checking package docs and bundled references, use a small compile probe instead of guessing. ## Mandatory policy - Ground stream keys and schema from MCP or user input. Do not invent field names, type names, or stream keys. - Prefer built-in `Deltix.Timebase.Api.Messages` types when schema matches, do not invent custom POCOs unnecessarily. - Use `TypeLoader` for custom bound types and QQL result POCOs. - When QQL authoring is central, use the QQL generator skill first. Return here for C# execution and binding when the user supplies final QQL. - Use placeholder-based credentials in `NuGet.config` and preserve any existing naming convention the project already uses. Never hardcode Nexus credentials. If restore fails with 401, report that the configured credentials are missing or incorrect. - Keep `ITickDb` and cursor lifecycle explicit (`using` or `finally`). - Start read-only unless writes are required. Do not write to streams unless the user asked. ## MCP-first workflow When the task depends on live server context: 1. `get_server_configuration` 2. `list_streams` 3. `get_stream_schema` 4. `get_stream_time_range` and `get_stream_symbols` when needed 5. Generate C# using grounded names and types from those results If MCP is unavailable, state what is missing and ask the user for stream/schema context before finalizing bound types. ## Capability map - [`references/workflow-selection.md`](references/workflow-selection.md): routing table - [`references/mcp-assisted-discovery.md`](references/mcp-assisted-discovery.md): MCP discovery order - [`references/project-setup-and-nuget.md`](references/project-setup-and-nuget.md): packages, feed, credentials, verification - [`references/message-types-and-schema.md`](references/message-types-and-schema.md): POCOs, introspector, `TypeLoader` - [`references/cursor-and-streams.md`](references/cursor-and-streams.md): connect, select, cursors, live, reverse reads - [`references/qql-bound-queries.md`](references/qql-bound-queries.md): `ExecuteQuery`, result POCOs - [`references/authentication.md`](references/authentication.md): MSAL + `AccessToken` - [`references/api-discovery.md`](references/api-discovery.md): API checks - [`references/debugging-and-performance.md`](references/debugging-and-performance.md): NuGet, binding, auth failures