Parley: Federated, decentralised chat that speaks plain IRC
Federated, decentralised chat that speaks plain IRC.
Parley is a chat network with no centre. Every person (or team) runs a small instance for their own domain. Instances find each other through DNS and well-known identity documents, exchange signed messages over HTTPS, and present the whole federated network to ordinary IRC clients such as irssi, WeeChat or Textual, with no plugins.
Identities look like email: alice@foo.com runs on foo.com, bob@bar.com on bar.com. Bob types /msg alice@foo.com hi and it just works, even if the two instances have never heard of each other before.
Status: working proof of concept. It demonstrates the design end to end and runs a real instance, but it is not hardened yet. See Limitations.
Two instances (foo.com and bar.com), two stock irssi sessions.
Alice connects to her instance; Bob connects to his:
Bob opens a query with /msg alice@foo.com and the two instances federate on the spot. Alice sees Bob as bob on bar.com; Bob sees Alice as alice on foo.com:
Both join #lobby, a global channel replicated across their instances:
Then, in two terminals:
-insecure and -resolve exist only for local development. In production each instance has a real domain, a TLS certificate, an SRV record, and finds peers via DNS.
demo/ brings up CoreDNS (authoritative for foo.com and bar.com, with _parley._tcp SRV records), a local demo CA, and both instances in Docker, then runs scripted IRC sessions and prints the evidence:
The container image is prologic/parley, and docker-compose.example.yml is a starting point. An instance for example.com, reachable at chat.example.com, needs:
A place to run it, with /data on persistent storage (it holds the instance key, the peer cache, the channel logs and the accounts):
Then create accounts with parleyctl (it is in the image too) or the admin page:
Without an admin token and with no accounts yet, parleyd logs a one-time /setup URL that creates the first admin in the browser. Single sign-on through OpenID Connect or a reverse proxy’s identity headers is described in docs/AUTH.md; SSO users mint IRC tokens for their clients on their settings page.
HTTPS in front of port 8443 on chat.example.com. Any reverse proxy that terminates TLS will do; parleyd itself serves plain HTTP unless you give it -tls-cert and -tls-key.
An SRV record so other instances can find you:
Without it, peers fall back to https://example.com/.well-known/parley/.
IRC over TLS for your clients. parleyd’s IRC listener is plaintext, so terminate TLS in front of it. With Caddy’s layer4 module, for example:
Then, in irssi: /connect -tls -tls_verify chat.example.com 6697
The port here is whatever your proxy listens on. If it is not 6697, start parleyd with -irc-port (and -irc-host, if IRC is on a different name to the endpoint), or set PARLEY_IRC_PORT / PARLEY_IRC_HOST:
The landing page, the settings page, parleyctl and the instance document all print a connect line from it, and the settings page prints a live token on that line. A wrong port under a right hostname still passes certificate verification, so the token would go to whatever else is listening there.
Check it from the outside. parleyctl check probes an instance the way a peer does — SRV record, well-known documents, the advertised endpoint, the inbox, and the IRC TLS port — and says what to fix:
It needs no token and works against anyone’s instance, so it is also how you tell a peer what is wrong with theirs. The common failure is a missing SRV record: the instance is perfectly reachable at its own host, but nobody resolving the identity domain can find it. Add -resolve https://chat.example.com to probe the host directly while DNS is still wrong, and -json for a machine-readable report. It exits non-zero if any check fails.
The wire format is documented in docs/PROTOCOL.md.
There is no config file. Configuration is in two places and each thing is in exactly one of them.
Flags, each with an environment variable, for what the process needs before it can open its database, what describes the machine and network it sits on, and the secrets and trust decisions about who may assert an identity. A flag wins over its variable. Only -domain is required.
Settings, in the database, for everything an administrator might change while the instance runs. They take effect the moment they are saved, with no restart, and have no flag and no environment variable. Change them on the admin page, through PUT /api/v1/settings (docs/API.md), or with parleyctl:
Only what differs from the defaults is stored, so an upgrade that changes a default changes it for every instance that never touched that key.
People set their own picture under Settings in the web interface, or it comes from their identity provider’s picture claim at login and is re-hosted here. It is published to IRC clients as the IRCv3 avatar metadata key and to other instances in the well-known user document; see docs/PROTOCOL.md.
The instance’s logo is not in this table, because it is not text: upload one PNG of at least 512 pixels along its longest side under Settings -> Logo in the admin page and Parley derives the favicon, the home-screen icon and the square an IRC client shows beside the network. A square is ideal, and a wordmark is fine — anything up to three times as long as it is tall is centred on a transparent square rather than refused. Until then every instance shows Parley’s own icon, which is why two of them look alike in a client’s network list.
Chat help. /help (or /quote HELP
Endpoints: /healthz for liveness, /api/v1/status for a JSON status of peers and channels, /metrics for Prometheus, and the API in docs/API.md.
Upgrading from a config file. parleyd -config config.json no longer reads the file: it prints, for every key in it, the flag, variable or setting that key has become, and exits. Move the process-level keys to your unit file or compose file, start the instance, then parleyctl settings import config.json applies the rest in one go and names what it skipped.
With TLS terminated in front of the IRC listener, every client arrives from the proxy: the logs name the wrong host, and per-address limits either do nothing or lock everybody out at once. List the proxy in irc_proxies and it must then prepend a PROXY protocol header (v1 or v2) to each connection.
This is two changes, and neither works alone. Listing a proxy that does not send a header drops every connection from it; sending a header from an address that is not listed feeds it to the IRC parser as garbage. There is no safe order, so change both together and be ready to put both back.
The default is empty, which is the whole thing switched off. 127.0.0.1/32 below is an example, not a default — substitute the address your own connections actually arrive from:
Note the name: PARLEY_TRUSTED_PROXIES is the web listener’s equivalent and a different decision entirely.
To find the address to list, connect once and read the log. Every client address is reported the first time it is seen:
Behind a proxy every client shares one address, so that is a single line naming exactly what belongs in irc_proxies. It is always the address on the socket, never the one a header carries — the header address could never match the list, so reporting it would hand you a value guaranteed to fail. Once the proxy is listed and sending headers, the line reappears for it with trusted_proxy=true, which is the confirmation that the two halves now agree.
Only listed addresses are believed, and a connection from one of them that does not carry a header is dropped rather than treated as a direct connection — accepting both shapes from the same place hands back the address forgery the header exists to stop. Those drops are counted in parley_irc_proxy_rejected_total, which is the metric to watch while making the change.
The web listener has the same blindness and its own setting. Behind a reverse proxy every request arrives from that proxy, so the per-address gates on web login, the federation inbox and feed reads all share one bucket — a global rate limit wearing a per-address name. List the proxy in http_proxies and X-Forwarded-For is believed from it, and nothing else changes.
Use that rather than auth.trusted_headers.proxies, which looks like it would do the job and does far more: a proxy on that list may assert who the user is, so a request to /login carrying Remote-User is logged in without a password. Fixing a rate limit is no reason to turn on passwordless login. The identity list does imply the address one, since a proxy trusted that far is not one to doubt about an address.
The step-by-step version, including the order that costs one outage instead of two, is in docs/PROXY.md.
With real addresses in hand, max_conns_per_addr becomes safe to turn on, and turning it on also applies the per-address login bucket to IRC. Leave it at 0 while the listener sits behind an unlisted proxy: every client shares one address there, so the cap would not limit anybody in particular, it would lock out everybody at once. It is a setting, so turning it on is parleyctl settings set max_conns_per_addr 8 and needs no restart. The per-account login backoff applies either way — see docs/AUTH.md.
/metrics serves the Prometheus text format: connections, accounts online, channels, peers linked, and counters for pushes, inbox events, feed reads, tag messages and what was refused. It needs an admin token by default, since how many people are on an instance is the operator’s business; set the metrics_public setting to serve it openly. Every sample is a count — no nicks, no channel names, no peer domains.
<data_dir>/identity.key is the one file that cannot be regenerated. The domain’s identity is the keypair: lose it and every peer that has cached the old public key refuses the instance, and the only fix is a new key that everyone has to re-trust. Back it up on the host, off the host:
If the key ever leaks, replacing it is a supported operation rather than a disaster:
Peers recover by themselves. A signature they cannot verify makes them
re-read the instance document once, which is where they find the new public
key, so the cost is one failed request each — and if that request was a
hello, a few minutes of backoff before they try again. The old key is kept
as identity.key.
These read and write the data directory directly rather than going through the API, because an admin token must never be able to fetch the private key over the network. Run them on the instance host, with -data-dir or PARLEY_DATA_DIR pointing at the data directory.
Nothing to run: the database gains its new tables on first start and the old ones are untouched. What follows is the handful of things that changed under you, newest first.
How much one account may say is now bounded. message_rate (1 a second) and message_burst (20 at once) apply to everybody but bots, keyed by the account, so a person’s clients share one budget. A refused message is answered 439 naming the target and is delivered nowhere. Every instance before this had no bound at all, so if yours has a room busier than that, raise the numbers or set message_rate to 0, which is the old behaviour:
It is a setting, so it lands without a restart.
Somebody on another instance is alice:foo.com, not alice/foo.com. The separator was borrowed from draft/relaymsg, and it was the wrong half of the convention to copy: a strict client guards against mistaking a server name for a nick by requiring both a . and a : or neither, and a name with a domain has a dot and no colon. Such a client read the whole prefix as a server name and dropped every JOIN, PART, QUIT, NICK and AWAY from a remote user, while PRIVMSG degraded quietly — which is why chat looked fine and no roster ever updated. PARLEYSEP in ISUPPORT says which character is in use, so a bot should read it from there rather than hardcode one.
The trap while a network is mid-upgrade: mention text crosses federation as bytes. Somebody on a peer that is still on / types alice/foo.com, and it does not match anything here until they upgrade. Tell your peers rather than letting them find it.
A reaction sent to a peer older than v0.5.0 is lost, not queued. Those versions answer an event type they do not implement with a 422, and a refusal is final to the sender’s outbox: the event is dropped and the sender is told the send failed. From v0.5.0 on, an unimplemented type is answered 200 {“unsupported”: true} instead, so this is the last change that has to wait for the whole mesh. Reactions between people her