CLAUDE.md — minder

1# Minder

3Scheduled task channel server for Claude Code sessions, built with Sigil.

5## Architecture

7Minder is an MCP channel server that manages cron-based scheduled tasks and

8pushes events into a running Claude Code session via the `claude/channel`

9protocol.

11```

12minder/

13├── package.sgl # Package definition

14├── dev-redirects.sgl # Points deps at local sigil + sigil-later

15├── minder.yaml # Schedules (optional)

16├── src/minder/

17│ ├── main.sgl # Entry point: channel MCP server

18│ ├── config.sgl # Config loading (YAML)

19│ └── scheduler.sgl # Cron scheduling via sigil-later

20└── test/

21 └── test-config.sgl

22```

24## Configuration

26Schedules via `minder.yaml`:

27```yaml

28schedules:

29 check-services:

30 cron: "*/30 * * * *"

31 prompt: "Check service health"

32```

34## Dependencies

36- **sigil-mcp** — MCP server framework (channel notifications)

37- **sigil-later** — Cron-based task scheduling

38- **sigil-yaml** — Config file parsing

39- **sigil-log** — Structured logging

41## Building

43Always build within a Guix shell:

45```bash

46guix shell -m ../sigil/manifest.scm -- sigil deps install

47guix shell -m ../sigil/manifest.scm -- sigil build -c release

48```

50Use installed Sigil 0.23.3 with `SIGIL_REDIRECTS` unset for releases.

51The lock selects published registry packages. Release C compilation uses

52GCC with `-march=x86-64 -mtune=generic` for CPU portability.

53Use `--redirects dev-redirects.sgl` only for local dependency development.

55## Testing

57```bash

58guix shell -m ../sigil/manifest.scm -- sigil test

59```

61## Running

63Minder is designed to be spawned by Claude Code as a channel MCP server:

65```bash

66claude --channels server:minder

67```

69Register it in `.mcp.json`:

70```json

71{

72 "mcpServers": {

73 "minder": {

74 "command": "./build/dev/bin/minder",

75 "env": {}

76 }

77 }

78}

79```

81## Stale Cache

83After rebuilding, clear the global module cache:

85```bash

86rm -rf ~/.cache/sigil/lib/0.7.0/minder/

87```

89## Key Implementation Notes

91- YAML dict keys from `yaml-decode` are **keywords** — use `keyword->string`

92- Struct constructors match the struct name (not `make-` prefixed)

93- The MCP server loop runs inside `with-async` so scheduler goroutines

94 can interleave with stdin reads

95- `channel-notify!` from `(sigil mcp channel)` sends channel events

96- sigil-later tasks spawn their own goroutines via `later-every!`