01Differentiator
Runtime-level supervision
An advisor model the executor cannot bypass. CONTINUE / REDIRECT / HALT enforced before any reply ships.
Arbiter Runtime · Open source
Multi-agent orchestration with the supervision built in.
An open-source agentic runtime that pairs an executor with an advisor — at the runtime layer, not as a slash command the agent can ignore. Three runtimes, one binary, one storage layer.
02Deploy
Three runtimes from one binary
Interactive TUI, one-shot send, multi-tenant HTTP+SSE server. Same agents, same memory, no service mesh.
03Memory
Memory that ranks
Tiered retrieval with reranking — a higher-accuracy path and a low-latency path. Pick the tier per call.
04Architecture
No JSON tool-use schema
Slash commands inline in replies, parsed off the stream. Model-agnostic, debuggable, smaller surface.
Interactive · TUI
$ arbiterA multi-pane terminal you live in.
Persistent panes for chat, memory, fleet, and tool tail — visible at the same time, not behind subcommands. Background loops stream into a tail pane while you keep typing in the foreground.
- Vim-style motions, fuzzy command palette, no mouse needed.
- Independent conversations per pane.
- Session restore per cwd.
agent · session titlestatus/stats
streamed model output, tool-call summaries, /cmd
results, system messages …
[3 tool calls…]
❯user input here, multi-line if it wraps
esc interrupt · pgup/dn scroll · /agents · /help
One-shot · scriptable
$ arbiter --send "…"Pipe-friendly for any workflow.
Send a single turn from a shell, get the answer on stdout, exit. Drops cleanly into Make targets, git hooks, CI steps — anywhere you already shell out.
- Same agents and memory as the TUI.
- Streams tokens to stdout; exit code reflects the gate.
- Cron-friendly — no terminal needed.
$arbiter --send "audit auth flow" --agent index
Reviewing the login handler…
Two race conditions in /login:
1. session token written before validation.
2. logout race on concurrent refresh.
gate: continue ✓ · $0.0021 · exit 0
$
Server · HTTP + SSE
$ arbiter --apiThe API your workspace consumes.
Multi-tenant orchestration server on :8080. Bearer-token auth, per-tenant isolation, full CRUD over agents / conversations / memory / artifacts, streaming SSE for every turn.
- OpenAPI 3.1 spec, versioned at
/v1/. - Pluggable billing via
ARBITER_BILLING_URL. - Cancellable requests via
/v1/requests/:id/cancel.
arbiter ↗ POST /v1/orchestrate
agent: index message: "audit auth flow"
request_receivedreq_8s3z
stream_startindex · depth 1
tool_call/parallel (3 children)
tool_call/mem read (consulted 4)
gateverdict: continue ✓
doneok=true · 1.4s · $0.0021
Capabilities
More than an executor and a loop.
The runtime ships the hard parts of agentic software as first-class primitives — durable execution, a memory graph, sub-agent delegation, versioned outputs — not glue code you maintain yourself.
Durable execution
Every turn is journaled. Drop the connection mid-stream, reconnect with a sequence cursor, and pick up exactly where you left off — nothing re-run, nothing re-billed.
Learn moreStructured memory
A queryable graph of memory entries and relations — not a flat vector dump. Agents read, write, and rank across it as the workflow runs.
Learn moreAgent-to-agent delegation
Agents spin up sub-agents and fan work out in parallel. The whole tree streams back as one ordered event sequence.
Learn moreVersioned artifacts
Durable, addressable outputs. Every file or document an agent produces is versioned and diffable — not lost when the turn ends.
Learn moreMCP tool servers
Connect Model Context Protocol servers once and the runtime exposes their tools to every agent — no per-agent wiring.
Learn moreScheduled runs
Cron-style scheduling built in. Kick off agent workflows on an interval, with no terminal attached.
Learn moreOpen source
Build from source. Ship from the terminal.
The runtime is open source — clone, build, run. Or grab a pre-built native binary. Either way, the cloud workspace and the local CLI talk to the exact same HTTP API.
Read the docs