Agent Bus MCP server
Durable addresses and crash-safe FIFO mailboxes so AI agents message each other, free.
Little public usage data yet
Reviews
Write oneNobody has reviewed Agent Bus yet.
If you have run it, two minutes of your experience saves the next person an afternoon.
Agent Bus tools (25, 2 write)
write = sends, deletes, buys or postsabout_flow_aiFreeWhat Flow AI is, how routing and pass-through pricing work, and how to point an agent or SDK at it (base URLs for OpenAI, Anthropic, and Codex protocols).
bus_ackFreeFlow Agent Bus: acknowledge durable receipt of a leased message WITHOUT replying (pass message_id + lease_id, read from the bus_inbox response as messages[0].message_id and messages[0].lease.lease_id). CAUTION: if the message expects a reply, ack does NOT free your mailbox — nothing new arrives until you bus_reply (or nack) it; the response's slot_released tells you which case you are in. If no answer is actually due (an announcement, or a sender who left expect_reply on by default), pass final:true — that frees your mailbox and records the decision, so the sender sees delivered rather than replied. A reply implies ack, so you don't need both.
bus_agentsFreeFlow Agent Bus: directory of your agents — address, harness, machine, status. Addresses look like agent://project/name.
bus_cancelwrite actionFreeFlow Agent Bus: withdraw a message YOU sent that is still queued (not yet leased). Returns its final status; a message already leased or replied cannot be cancelled.
bus_checkFreeFlow Agent Bus: status of a message you sent — queued | leased | delivered | replied | dead_letter | expired | cancelled — with the reply once it exists. terminal:true means stop waiting; reply_declined:true means the recipient closed it without answering.
bus_configureFreeFlow Agent Bus: change your OWN mailbox settings WITHOUT claiming a message — accept_from, harness, webhook_url/webhook_format/webhook_headers (or "" to clear). Same fields as bus_inbox's settings, but this tool can never take a lease, so configuring never steals a live message.
bus_healthFreeFlow Agent Bus: your ACCOUNT's health — median reply latency (are agents listening?), who is listening now, push coverage, stuck mailboxes (mail nobody is collecting), volume. The diagnostic an orchestrator needs before blaming a peer.
bus_historyFreeFlow Agent Bus: your past mail — sent or received (owner keys: the whole account), bodies within the 30-day retention, dead letters included. Filter by peer (with), thread (trace_id), status; page with before = the previous page's next_before.
bus_inboxFreeFlow Agent Bus: claim the next message addressed to you as a LEASE (at most one at a time, strict FIFO). Settle it with bus_reply (or bus_ack) before the next is offered; if you crash, the lease expires and the message is re-offered. Pass wait_s (1-25) to long-poll: the call holds until mail arrives — near-instant delivery, no busy loop. TERMINAL SESSIONS (Claude Code, Codex): do not poll from inside your session — run the DOORBELL beside it once, with your user's approval, and you are woken when mail lands (https://api.flowaiapi.com/v1/bus/doorbell.py; GET /v1/bus/onboard Part 2). Call bus_inbox when the doorbell rings, or at task boundaries. NOTE: wait_s>0 over MCP holds YOUR model turn open for up to 25s — it is only free from a shell loop or the doorbell. Per-invocation agents: use the webhook or a sidecar, not a blocking MCP call.
bus_inviteFreeFlow Agent Bus: mint a one-time INVITE CODE so a new teammate can join your team by itself (bus_join) — a code is not a key, so a human can relay it safely. A bus key invites into its own project; an owner key names the project. Default 1 use, 24h.
bus_joinFreeFlow Agent Bus: join an EXISTING team with an invite code (no key needed). A teammate made the code with bus_invite; you get your own bound key on their account, shown once. Then bus_configure {harness, accept_from:["*"]} to activate.
bus_manageFreeFlow Agent Bus: manage your account's agents — the owner/self-service surface. actions: remove_agent (address) | set_accept_from (address, accept_from[]) | set_harness (address, harness) | set_notify (address or '*', webhook_url, webhook_format, webhook_headers) | delete_messages (message_ids[]) | rotate_key (address: new key shown once, old keys stop) | revoke_key (address). You may manage what you could have minted: your own project with a bus key, the whole account with an owner key. set_notify verifies the webhook with one ping before saving it. Every action is audited; deleting content leaves a tombstone, never rewrites who-sent-what-when.
bus_meFreeFlow Agent Bus: inspect your OWN mailbox — who may message you (accept_from), unread queue depth, the lease you are holding (and whether it blocks your mailbox), webhook state. Call this FIRST when the bus seems stuck.
bus_mintFreeFlow Agent Bus: create bus keys for NEW teammates. With a bus-scope key you may mint only under your own project (agent://<yourproject>/<name>); an account-owner (full-scope) key may mint into any project on the account. Up to 8 per call, 32 per project. Each key is shown ONCE — hand it to that agent privately, never as a bus message. Minted keys are bus-only (cannot spend on inference).
bus_nackFreeFlow Agent Bus: return a leased message you could NOT process (pass message_id + lease_id and a short error). retryable:true re-offers it on the next poll (four failures dead-letter it); retryable:false dead-letters it now. Never nack something that merely needs no reply — use bus_ack with final:true for that.
bus_renewFreeFlow Agent Bus: extend the lease on a message you are still working on (pass message_id + lease_id). Each renewal adds the standard lease (15 min); total lease time is capped at 6h from first claim. Use it for hour-long work instead of letting the lease expire and the message be re-offered to someone else.
bus_replayFreeFlow Agent Bus: re-queue a dead-lettered or expired message addressed to you (owner keys: any). Attempts reset, a fresh 24h lifetime applies, the doorbell rings. Find candidates with bus_history {status:"dead_letter"}.
bus_replyFreeFlow Agent Bus: reply to a message you received via bus_inbox (creates a first-class reply message and implies acknowledgment). Pass the lease_id (messages[0].lease.lease_id in the bus_inbox response) to fence a stale worker.
bus_sendwrite actionFreeFlow Agent Bus: send a durable message to another agent on your account (agent://team/name). The recipient is woken by its doorbell/webhook if it has one; otherwise the message waits — the response's recipient_status/delivery_note say which. Need an answer? verb:"ask" and fetch it with bus_check. The response carries your quota {limit, remaining, reset_s}. Requires your bus or owner key.
bus_signupFreeFlow Agent Bus: create a NEW, ISOLATED team account (free, no registration). FIRST agent of a team only. If your user already has agents on the bus, use bus_join (with a code from a teammate's bus_invite) — a second signup cannot see the first account, and a signup that presents an existing key is refused (already_on_bus). Returns your agent:// address and key (shown once). Then: bus_configure {harness, accept_from:["*"]} to activate; run the doorbell with your user's approval; bus_invite or bus_mint to bring teammates. Manual: https://api.flowaiapi.com/v1/bus/onboard (also the bus://onboard resource).
convene_councilFreeConvene a council of DIVERSE AI models to critique a proposal or decision you are uncertain about. Each model independently assesses it, then a synthesis merges agreements, disagreements, and a recommendation. Requires your Flow AI API key in the Authorization header (billed at pass-through cost — typically well under a cent).
delegate_taskFreeHand a self-contained subtask to the cheapest model that can complete it — offload work that doesn't need your own (expensive) model, to save tokens and move faster. Returns the result, which model served it, and the exact cost. Requires your Flow AI API key in the Authorization header.
get_live_pricesFreeFlow AI's live market book: clearing prices vs published list prices per model, with savings percentage. Sorted by savings. These are the prices requests actually clear at.
list_free_modelsFreeThe canary-verified FREE models currently promoted into Flow AI's default routing pool. Each passed a live tool-calling + output-quality canary; they serve at $0 per token.
search_modelsFreeSearch Flow AI's live model catalog by name/provider/family. Returns id, provider, context window, per-token prices and verified capabilities for up to 20 matches.
Public scan report
scanner v0.1.9 · 2026-09-20 · same rubric, same numbers if you re-run it
- –Code scanremote-only server, no package to scann/a
- Live reliabilityremote reachable in 2225ms17/20
- Tool poisoning25 tool descriptions checked15/15
- Auth qualityopen endpoint exposes 2 write-action tools with no auth3/15
- Maintenanceno repository listed3/15
- Maintainer identityverified namespace with website, no repo4/10
Findings (2)
- highWrite-action tools reachable without authentication
auth.open-write - lowNo source repository listed
maint.no-repo
Install directly
claude mcp add --transport http agent-bus https://api.flowaiapi.com/mcp
Agent Bus: common questions
- Is Agent Bus MCP server safe?
- With care: it is graded C, so read the findings first (56/100). Read the Agent Bus safety report
- How do I install Agent Bus?
- It runs remotely at api.flowaiapi.com. Add it to Claude Code, Claude Desktop or Cursor with the snippets above, or call it through the mcp.market gateway without installing anything.
- Does Agent Bus need an API key?
- Not as far as the registry entry and our scan can tell: no credentials are declared or required.
- Is Agent Bus maintained?
- The latest release is v1.0.0.
- Is Agent Bus up?
- 100% of our last 6 checks got an answer. We check remote servers about four times a day.
- What can I use instead of Agent Bus?
- Servers from other publishers that do the same job: Agent-Native Chat MCP server and Patchloom MCP server.
Alternatives to Agent Bus
Same job from other publishers: the closest match first, then the best rated.
- Agent-Native ChatMinimal chat-first app with durable threads, actions, and the app-agent loopnot reviewedEstablishedA
- PatchloomAgent-safe structured edits: JSON/YAML/TOML/md/AST, dry-run, batch/tx. Not a filesystem MCP.not reviewedGrowingB