Closes the "Claude Code as single primary" gap. Now `kei` (no args) execs
whichever CLI is configured as primary, and ANY MCP-capable orchestrator
can spawn KeiSeiKit agents on any backend via the built-in spawn_agent tool.
## A — orchestrator picker
bin/kei now reads ~/.claude/config/primary.toml and execs that CLI instead
of hardcoding claude. New arms:
kei pick interactive menu → set primary → launch it
kei --on=<backend> one-shot launch of <backend> (no primary write)
kei primary [<b>] get/set primary
Splash shows `primary CLI: <backend>` so the orchestrator is visible.
Failure mode: if primary's CLI isn't on PATH, prints install hint + offers
`kei pick` recovery.
scripts/kei-pick.sh — Constructor Pattern picker (<140 LOC). Lists all 6
backends with install status (✓/✗), highlights current primary, writes
choice to primary.toml, execs the picked CLI. Honors stdin TTY gate
(RULE TTY-INTERACTIVITY-GATE — -t 0, not -t 1) for non-interactive safety.
## B — spawn_agent MCP tool
_primitives/_rust/kei-mcp/src/handlers/tools.rs gains a built-in
`spawn_agent` tool, exposed alongside discovered atoms:
- inputSchema: { name: str, task: str, on?: backend-enum }
- Calls kei-agent-cli.sh internally with same DNA resolution
- 60s timeout, kill-on-drop
- Honors KEI_AGENT_CLI env for testing
Smoke 2026-05-26 (MCP stdio JSON-RPC round-trip):
spawn_agent(name=smoke-test, on=claude) → "SMOKE-OK" ✅
spawn_agent(name=smoke-test, on=grok) → "SMOKE-OK" ✅
Why it matters: Claude Code has a native Agent tool. Grok / Agy / Copilot /
Kimi don't have an equivalent native sub-agent surface — but they all speak
MCP. spawn_agent gives them KeiSeiKit's sub-agent capability when they're
the orchestrator. The chosen orchestrator no longer caps the sub-agent fleet.
## Other
_primitives/_rust/kei-mcp/Cargo.toml: tokio gains "io-std" feature (was
missing — main.rs uses tokio::io::stdin/stdout). This fixes a latent build
error unrelated to this PR (kei-mcp wasn't building cleanly before).
Tests: tools_list assertions updated for the +1 built-in tool (3 total
instead of 2 with atoms; 1 instead of 0 on empty root). All MCP tests pass.
Assembler 3/3 golden tests still pass (provider field is optional).
8.5 KiB
Multi-CLI agent invocation
Cross-LLM agent execution. Same agent definition, different backend. Same DNA, swap the brain. KeiSeiKit is no longer Claude-Code-only.
KeiSeiKit agents are markdown files. Any LLM CLI that takes a prompt can host them. Three call shapes:
kei agent <name> "<task>" # DNA-resolved (manifest → primary → claude)
kei agent --on=<backend> <name> "<task>" # override DNA
kei run-via <backend> <name> "<task>" # explicit backend (no DNA lookup)
Backends — smoke-tested 2026-05-26
| Backend | CLI | Flag | Smoke | Notes |
|---|---|---|---|---|
| claude | claude |
-p |
✅ | Claude Code, native --agent flag |
| grok | grok |
--print |
✅ | xAI Grok Build TUI, native --agent flag |
| agy | agy |
--print |
✅ | Google Antigravity (Gemini models). Alias: antigravity |
| copilot | copilot |
--prompt |
✅ | GitHub Copilot CLI (@github/copilot) |
| kimi | kimi |
TUI-only | ⚠ | No print mode — launcher saves prompt to tmpfile + opens TUI for paste. kimi acp JSON-RPC integration is future work. |
| codex | codex |
-p |
— | OpenAI Codex (register-only; not installed locally) |
Run kei run-via list to see installed backends, current primary, and agent names.
DNA — agent prefers a provider
Add provider to the agent manifest:
# _manifests/my-agent.toml
name = "my-agent"
provider = "grok" # preferred backend; optional
model = "grok-2" # advisory; informs choice but not yet sent through
The assembler emits it into frontmatter:
---
name: my-agent
provider: grok
---
Resolution order (each falls through if previous returns nothing):
--on=<backend>flag on the command lineprovider:field in agent manifest~/.claude/config/primary.toml(set viakei primary <backend>)- Default:
claude
Primary — your default LLM
kei primary # show current primary (and fallback)
kei primary grok # set default to Grok
kei primary claude # back to Claude Code
kei primary writes ~/.claude/config/primary.toml. Any agent without
its own provider: field will resolve to this. This is the lever to
"swap out Claude Code as the primary shell" — set primary to grok, and
every kei agent <name> runs on Grok.
Usage examples
# DNA mode (manifest's provider, or primary, or claude):
kei agent critic "review src/auth.rs"
# Override DNA — try the same agent on a different model for a second opinion:
kei agent --on=grok critic "review src/auth.rs"
kei agent --on=agy critic "review src/auth.rs"
kei agent --on=copilot critic "review src/auth.rs"
# Explicit backend, no DNA lookup (legacy):
kei run-via grok critic "review src/auth.rs"
# Point at an arbitrary agent file:
kei agent --on=grok --file=/tmp/my-agent.md "do the thing"
# Native --agent flag (grok/claude only):
KEI_NATIVE_AGENT=1 kei agent critic "review src/auth.rs"
How it works
- Resolves backend from DNA (see above).
- Reads
~/.claude/agents/<agent-name>.md(assembler-generated prompt). - Strips YAML frontmatter.
- Composes with task:
<agent prompt>\n\n---\n\nTASK FOR THIS RUN:\n<task>. - Execs the backend's non-interactive CLI with the composed prompt.
No agent file is modified. No new tokens are issued — subscription authentication is whatever each CLI uses (its own login / config dir).
When to use each
This is a tool, not a recommendation. Each backend has different strengths; the substrate is agnostic about which you pick. Pick by:
- Familiarity — the CLI you already use day-to-day.
- Subscription cost — burn the one with cheaper marginal cost first.
- Specific feature — e.g.
grok --agentfor native sub-agent switching mid-conversation;agy --sandboxfor terminal restriction. - Independent second opinion — same agent, different model, see if conclusions diverge.
Orchestrator picker — kei no longer hardcodes claude
Without args, kei reads ~/.claude/config/primary.toml and execs that CLI.
The picker lets you change it interactively:
kei pick # interactive menu → set primary → launch it
kei # splash → exec the configured primary
kei --on=grok # one-shot launch of grok (does NOT change primary)
kei primary grok # set default to grok (no launch)
kei primary # show current primary
The splash shows primary CLI: <backend> so you always know which orchestrator
will start. If the chosen primary isn't installed, kei prints the install
command and offers kei pick as recovery.
Cross-CLI sub-agent spawn via MCP — spawn_agent
kei-mcp exposes a built-in spawn_agent MCP tool. Any CLI that connects
to it as an MCP client can invoke KeiSeiKit agents on any backend, no matter
what the orchestrator is:
{
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"name": "spawn_agent",
"arguments": {
"name": "critic",
"task": "review src/auth.rs for race conditions",
"on": "grok"
}
}
}
Internally spawn_agent shells out to kei-agent-cli.sh with the same DNA
resolution as kei agent. The on argument is optional — without it, the
backend is picked from the agent's manifest, then primary.toml, then claude.
Why this matters: Claude Code has a native Agent tool for sub-agent
spawning. Grok / Antigravity / Copilot / Kimi do NOT have that surface
natively — but they all support MCP. With spawn_agent exposed via kei-mcp,
every backend that speaks MCP gets KeiSeiKit's sub-agent capability. So
when Grok is your orchestrator, it can still spawn critic on Claude (or
code-implementer on Antigravity, or anything else) — the orchestrator
choice no longer caps your sub-agent surface.
Wire kei-mcp into the orchestrator's MCP config (each CLI has its own):
| CLI | MCP config |
|---|---|
| claude | ~/.claude/settings.json mcpServers block |
| grok | ~/.grok/config.json (or check grok --help) |
| agy | ~/.antigravity/mcp.json (check agy plugin list) |
| copilot | ~/.copilot/mcp.json (check copilot --help) |
| kimi | kimi mcp add subcommand |
Point each at <kit>/_primitives/_rust/target/release/kei-mcp (built via
cargo build -p kei-mcp --release).
Rule enforcement caveat (READ THIS)
KeiSeiKit hooks (numeric-claims-guard, citation-verify, no-github-push,
safety-guard, push-to-main, etc.) are Claude Code-side:
PreToolUse:Bash / :Edit / :Write events that fire inside Claude Code's
process. They do not propagate to grok / agy / copilot / kimi.
That means:
- Prompt-level rules (the agent's instructions inside the
.md) DO carry through — the agent reads Constructor Pattern, Evidence Grading, No Hallucination, etc. as part of its system prompt on any backend. - Tool-level enforcement (hard-deny on
git push github.com, citation guard, etc.) only applies on the claude backend. Other backends' tool surfaces are governed by THEIR own hooks/policies.
If you need true rule-enforcement on a non-claude backend, the path is
the MCP server (_primitives/_rust/kei-mcp/): registers KeiSeiKit
primitives as MCP tools that the other CLI invokes. Tool-side policies
travel with the MCP wrapper, not with the CLI.
Adding a new backend
- Add a
[backend.<name>]table to_primitives/cli-backends.toml. - Add a case arm in
scripts/kei-agent-cli.shbackend_bin()andbackend_invoke()for the new CLI's print-flag. - Add a row to the smoke-test table above (state PASS/FAIL/PARTIAL).
What it is NOT
- Not a router — picks no backend for you; you (or DNA) ask, it dispatches.
- Not a federation — each backend runs independently with its own context; there is no cross-backend state.
- Not a rule-enforcement layer — hooks only fire on the claude backend (see caveat above). For non-claude rule enforcement use MCP server.
- Not a wrapper around the backend's tool surface — what the CLI can do (Bash, file edits, MCP, etc.) is determined by that CLI, not KeiSeiKit. The substrate only ships the prompt.
Related
_primitives/_rust/kei-llm-router/— Beta-posterior router for programmatic model selection inside Rust code (a different layer)._primitives/_rust/kei-mcp/— MCP server that exposes KeiSeiKit primitives to ANY MCP-compatible client (Cursor / Continue / Zed / Aider / Cline / Windsurf / OpenClaw).