hyperguild/docs/superpowers/specs/2026-05-03-hyperguild-cli-design.md

Spec: hyperguild CLI

Plan 4 of 7 — Hyperguild Skill Migration. Loaded after feature-spec skill.

Problem Statement

Three needs converge on a single small Go binary:

1. Tier probing as MCP is overkill. The supervisor's tier MCP runs on koala:30320 and answers a one-shot question (which models are reachable right now?). Pulling Claude Code through MCP startup, tool listing, and a JSON-RPC call for a 2-second probe is wasteful and adds a network hop the answer doesn't need.
2. Brain access from shell scripts has no good front door. The brain's HTTP REST API exists (Plan 1) at koala:3300 for non-MCP clients, but every shell script that wants to query or write to the brain re-implements the curl invocation. A CLI gives shell pipelines, ad-hoc agent prompts, and quick-debug scenarios a stable interface.
3. Mode bootstrap is manual. Each new project that wants to operate in a chosen mode (cloud / client-local / sovereign) needs a .mcp.json written by hand. Without automation, mode adoption is gated on remembering the right MCP server URLs.

Why now: Plans 1–3 are merged. The CLI is the next building block in shrinking the supervisor pod toward a thin Mode-2 routing layer. Plans 5 and 6 build on the CLI's tier and brain helpers.

Success Criteria

• hyperguild tier returns the same tier.Info that internal/tier.Detect produces for the same probe URLs, in < 3 s under all three tier conditions, with both human-readable and --json output.
• hyperguild brain query <topic> returns BM25 results from the brain HTTP REST /query endpoint, exit 0 on success and non-zero on transport failure.
• hyperguild brain write <type> <slug> reads markdown content from stdin, posts to /write with the type and slug, and creates brain/knowledge/<slug>.md. A round-trip (hyperguild brain query <slug> immediately after) finds the entry.
• hyperguild mode <cloud|client-local|sovereign> writes a parseable JSON file at the target path with the per-mode mcpServers entries; jq -e .mcpServers succeeds on the output.
• All commands print usage on --help, exit 2 on unknown flags, exit non-zero on operational errors.
• task check passes (lint + test + vet) on each task and on the merged branch.

Constraints

• Stdlib only. No cobra, urfave/cli, viper, etc. CLI router and flag parsing use flag.NewFlagSet.
• Go 1.26.1, project default.
• Module: github.com/mathiasbq/supervisor, peer to cmd/supervisor/. New code at cmd/hyperguild/. The module name keeps its historical supervisor value — renaming the module is out of scope and would touch every import.
• Reuse internal/tier unchanged. The CLI is a thin wrapper around tier.Detect.
• Brain endpoint configurable via BRAIN_URL env var (default http://koala:3300). No hostname literals embedded in the CLI body — sourced from env per the existing "logical-addresses-in-instructions" memory.
• Test discipline: table-driven, testify, fakes for HTTP and tier probing. No live network in tests.
• Errors: wrapped via fmt.Errorf("op: %w", err). No naked returns. Stderr for errors, stdout for results.

Out of Scope

• The Mode 6 routing pod itself — mode client-local writes a placeholder entry pointing at the future routing URL with a _routing_pending annotation; the CLI does not provision the pod.
• Pass-rate logging (Plan 5) — the CLI's brain write does not emit session_log events.
• Skill worker CLIs (hyperguild tdd_red, hyperguild review, etc.) — those stay on the supervisor MCP until Plan 7.
• Brain HTTP server changes — the REST endpoints already exist.
• Authentication / TLS — Tailscale provides network isolation; no auth currently.
• Windows/Linux binaries — macOS-only per the user's setup. go build is portable but no cross-compilation in CI.
• A crush config writer for Mode 3 — Mode 3 (sovereign) writes a Claude-Code-compatible .mcp.json with brain-only MCP, on the assumption that even Crush-primary users may fall back to Claude Code with brain access. Crush's own config is owned by the user manually.
• A unified --config file for the CLI — env var + flags is enough today.

Technical Approach

• Single binary, inline subcommand router. cmd/hyperguild/main.go dispatches on os.Args[1] to per-subcommand functions, each owning its own flag.NewFlagSet. Rationale: 4 top-level subcommands (tier, brain, mode, plus --help) and one nested level (brain query, brain write); ~80 lines of routing plumbing in stdlib beats pulling cobra's ~3 KLOC of dependencies for a tiny CLI. The router is testable by injecting args []string instead of reading os.Args directly.

• tier subcommand reuses internal/tier.Detect verbatim. Probe URLs (https://api.anthropic.com and the LiteLLM base URL) come from environment: ANTHROPIC_PROBE_URL (default the literal Anthropic URL) and LITELLM_BASE_URL (no default — error if --mode-needs-llm and unset). Rationale: matching the supervisor's existing wiring means the CLI cannot disagree with the supervisor about tier; a single source of truth.

• brain subcommand calls the HTTP REST API. Two nested subcommands:

  • brain query <topic> issues GET /query?q=<topic>&limit=<N> (default --limit 5), prints results in human-readable form by default and with --json for machine consumption.
  • brain write <type> <slug> reads stdin, posts POST /write with JSON body {type, slug, content}, prints the resulting path on success. Rationale: HTTP REST is simpler than MCP framing for a CLI. Per CLAUDE.md, the REST endpoints are documented as the official non-MCP interface.

• mode <name> writes a per-mode .mcp.json template. Defaults to writing ./.mcp.json (cwd); accepts --out <path>. Per-mode bodies:

  • cloud — mcpServers contains only brain at http://koala:30330/mcp.
  • client-local — mcpServers contains brain at http://koala:30330/mcp and a routing placeholder entry with url set to a marker (http://koala:30310/mcp) and an extra field "_routing_pending": "Plan 6 — routing pod not deployed yet". Rationale: keeping strict-JSON parseable means using a placeholder field rather than a JSON comment, which the spec parser would reject.
  • sovereign — mcpServers contains only brain, plus a top-level "_mode_note": "Sovereign mode primarily uses Crush + LiteLLM. This .mcp.json is provided as Claude Code fallback.". All three are valid JSON and all three round-trip through jq for verification. Rationale: a single subcommand with three clearly-different outputs is easier to evolve than three nearly-duplicate subcommands. The placeholder fields are intentional documentation in the file itself, which the user actually opens and edits.

• No global state. Each subcommand is a function (ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) error, allowing table-driven tests to exercise full subcommand flows without os.Exit or fd capture.

• HTTP client injection. A package-level http.Client with 5s timeout for brain calls, overridable in tests via a constructor. Real client for main, httptest.Server for tests.

Risks

• .mcp.json schema may evolve. Claude Code's MCP config format is defined by the harness, and Anthropic could change it. Mitigation: document the format in the CLI's --help text and in the spec; if it breaks, the fix is local to one template function.

• Brain endpoint hostname drift. If the brain moves off koala, the env-var override avoids breaking the CLI but the mode template's hardcoded koala:30330 becomes stale. Mitigation: source the URL in the mode template from the same env var (BRAIN_URL) so all three subcommands stay in lockstep with the user's actual environment.

• tier probe URL gap. The CLI inherits the supervisor's hardcoded https://api.anthropic.com probe URL via internal/tier. If Anthropic changes the URL, both supervisor and CLI break together. Mitigation: env-var override ANTHROPIC_PROBE_URL; default unchanged.

• No HTTP retry logic. The CLI returns first-error to the user. For ad-hoc shell use this is fine; for automation a future --retry flag may be needed. Out of scope for this iteration.

• Tests don't cover live network. Pure-fake tests catch regression but not "does the brain pod actually answer." Mitigation: add a smoke-test task hyperguild:smoke in a follow-up that runs against the real brain — separate concern, not in Plan 4.

• Mode 3 sovereign output may surprise users who expect Mode 3 to skip writing a .mcp.json entirely (since Crush is the primary harness). Mitigation: the _mode_note field explains the choice; the --out /dev/null escape hatch lets users skip the write if they want.