
wyd
io.github.oxyplayPublished by GitHub account oxyplayv0.10.0Updated Oct 27, 2026
Local runtime provenance for coding agents. Inspect sessions and explain which one owns a process.
Overview
Local MCP server that tells a coding agent which agent sessions and processes are running on the machine and who owns them.
- What you can do
- List recorded coding-agent sessions and inspect a single session's details
- Explain which session owns a given process ID, or name the system source instead
- Read managed runs: list runs, get one run, read its retained output, and check capacity
- Start and cancel supervised runs, only when the server is launched with the run flag
- When to use it
- Useful when you run coding agents all day and want an assistant to find leftover MCP servers, browsers, dev servers or workers, attribute them to a session and project, or run commands under a deadline and resource budget.
- Requirements
- Runs as a local process on macOS or Linux, started with the MCP subcommand over stdio; no account, network or API key. Starting or cancelling runs needs the flag that enables host execution, and the local supervisor starts on demand. Hard resource limits on Linux need a delegated cgroup v2 subtree.
Installation
In SourceWeft
- Open wyd in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
wyd
wyd? — what you doing?
See what your coding agents left running.
Coding agents spawn MCP servers, headless browsers, dev servers, workers, and databases.
ps tells you what is running. wyd tells you why — which session started it, in which project, and whether it's leftover.
Local, macOS and Linux. No account, no network, no telemetry.
Each tagged release publishes the crate to crates.io and bumps
Formula/wyd.rb in oxyplay/homebrew-tap
automatically, so wyd upgrade stays current with no manual step. wyd upgrade
still prints a hint if a formula bump is ever lagging.
Binaries: GitHub Releases. From a clone: cargo install --path .
[wyd TUI (wyd --demo) — 5 agent sessions, MCP servers, dev servers, databases and Docker]
OS daemons stay hidden. Desktop Chrome stays hidden. Agent-spawned Chromium does not.
Why wyd
Built for people who run coding agents all day and then ask what did that session leave behind?
Runtime ownership
Beyond the live view, wyd tracks coding-agent runtime sessions — which
resources a session spawned, keyed by boot_id + pid + start_time, so the
provenance survives process re-parenting and Wyd restarts. A deterministic
resolver attributes resources to a session with an explainable score when
exact ancestry is gone.
- Sessions view in the TUI (top-level): agent · project · state · age · id, with a details panel.
wyd why <pid>— which session owns a process, and the evidence. When no agent session owns it, it names the system source instead (systemd unit, launchd, cron, tmux, ssh, snap, flatpak, or an interactive shell), with the ancestry chain. Exit codes:0cleanly owned,1leftover/unattributed,2not running,5internal error.wyd --json sessions— recorded sessions as JSON.wyd serve— a local daemon over a Unix socket (wyd.sock, mode 0600, single-instance). Keeps provenance fresh and answers read-only queries; vendors can register sessions withsession_start/session_end(their id maps to a Wyd session as an alias).wyd mcp— a Model Context Protocol server over stdio, so a coding agent can ask wyd for its sessions, who owns a PID, and its managed runs (--allow-runadds host execution).
MCP
wyd also speaks the Model Context Protocol over stdio, so a coding agent
can ask the machine what it — or other agents — left running.
Starts the local MCP server. Read tools are always available:
list_sessions (recorded agent sessions), explain (which session owns a
process, by pid), list_runs, get_run, read_run_output and
get_capacity. --allow-run adds start_run and cancel_run for that
connection only — without it those calls are rejected with a message to
restart with --allow-run. No network, no account — the answers come from the
local provenance store.
Registered in the MCP Registry:
- MCP Registry name:
mcp-name: io.github.oxyplay/wyd
Managed runs
wyd run starts a command under a local supervisor, so an agent gets a
deadline, a process group wyd owns, and bounded logs instead of a hung shell.
The command is argv, not a shell — &&, pipes and globs need an explicit
sh -c. --timeout defaults to 10m, --grace (soft-to-forced stop) to
3s, and --cwd must be absolute. --json prints the structured result
instead of the captured output; repeating a --request-id within 24 hours
reuses that run instead of starting a second one, and the same id with a
different command is rejected.
Runs share one admission budget, so several agents on one machine do not all
start at once. wyd run takes a per-run resource request:
A run stopped by a monitored memory threshold ends outcome=resource_limit
and exits 137, with a limit_event naming the observed number.
Reservations are a budget, not measured RAM. reserved_memory_bytes is
the sum of what admitted runs reserved; it is not what they are using.
Measured usage is reported separately as observed_memory_bytes, which on
macOS is the sum of RSS over the run's process group sampled every 200 ms.
Shared pages can be counted more than once and a brief peak can be missed, so
it is an observation, not a guarantee.
On macOS there is no hard memory limit: aggregate_memory_limit is
monitored, and --enforce hard is refused before the run is created rather
than downgraded. On Linux hard limits come from a delegated cgroup v2
subtree (memory.max, memory.swap.max, cpu.max, pids.max), so
aggregate_memory_limit, cpu_quota and process_limit report available
when one exists. Without delegation they report unavailable and a hard
request is refused — wyd never asks for root and never rewrites your systemd
units. Put the supervisor in a unit with Delegate=yes, or point
WYD_CGROUP_ROOT at a directory you own inside a delegated subtree, and
restart the supervisor (capabilities are fixed at its start). Because cgroup
membership is inherited by every descendant, a setsid child that escapes the
process group is still inside the run's cgroup and is killed with it. Runs also
live under one aggregate cgroup whose memory.max is the run budget, so the
budget is a kernel cap on the total and not only an admission rule;
wyd capacity --set memory_budget_mb=… updates it. Set
cpu_budget_millicores and/or pids_budget in [runs] to cap the total CPU
and process count of all runs the same way (wyd capacity reports them, and a
change at runtime updates the kernel too).
Inspect or stop it afterwards:
wyd capacity shows the admission limits and what is in use; --json adds
the capability states (monitored vs available vs unavailable):
--set is repeatable and takes key=value for any [runs] key:
Changing a limit governs admission from then on; active runs are not killed
for it. When the new cap is lower than the number of runs already admitted,
the temporary exceedance is reported as over_parallel_limit instead of
hidden. The same keys live under [runs] in ~/.config/wyd/config.toml.
The TUI shows the same runs read-only: select Runs in the Overview pane,
enter opens a run's details. The Runs pane also shows the configured limits
(live counts are marked unavailable there, because the TUI reads the store, not
the supervisor socket) and, for a queued run, its position, wait and reason.
The web dashboard has the same view plus a live capacity panel; neither can
change a limit or start a command.
The supervisor owns the run, not the client that started it: if the CLI or MCP
connection drops, the run continues to its deadline and its result and logs are
still there afterwards. Reads are durable and daemon-free — wyd runs,
wyd logs and the MCP list_runs/get_run/read_run_output read the store
and the retained log files, so they work with no supervisor alive. wyd capacity and the web dashboard's capacity panel report the configured [runs]
limits with an empty queue when no supervisor is running, instead of starting
one; the MCP get_capacity tool asks the supervisor and starts it on demand,
like start_run. Starting or cancelling a run needs the supervisor, which
starts on demand and exits after five idle minutes; the next wyd run or
wyd mcp --allow-run brings it back. SIGTERM/SIGINT to the supervisor
stops its active runs first (up to 10s) instead of abandoning them.
Exit codes: the command's own code when it exits, 128+signal when it is
signaled, 124 on timeout, 130 on cancel, 125 when the command could not
be spawned, 137 when a resource limit stopped it. The precise reason is
always in the JSON (outcome, exit_code, signal, cleanup, detail,
limit_event).
Output is bounded per stream at 10 MiB and at 250 MiB total across retained
runs — the head is kept and truncation is reported
(stdout_truncated/stderr_truncated in JSON, a marker on stderr from
wyd logs). The pipe keeps draining after the limit so a chatty test cannot
wedge the supervisor. Finished runs and their logs are kept 7 days.
What this is not
Managed runs are local processes on macOS and Linux and nothing more:
- Cleanup covers the run's own process group. A command that leaves it —
setsid, double fork, an external daemon — is not silently claimed as covered:cleanupreportsincompleteorunknowninstead ofcomplete. TMPDIR,TMPandTEMPpoint at a run-owned directory. That is convenience, not a sandbox: the command can still write anywhere you can.- No filesystem, network or secret isolation, and no control over package installs. Run untrusted code in a container or VM, not here.
- A monitored memory limit is a policy, not a guarantee: a brief peak between
two 200 ms samples is missed, and shared pages can be counted twice. Hard
memory, CPU and process-count limits depend on the backend: macOS only
monitors, Linux enforces them through a delegated cgroup v2 subtree when one
is available — otherwise the capability reports
unavailableand ahardrequest is refused rather than approximated. Hard limits on macOS need a Linux execution backend (a container/VM); until that exists, run resource-limited commands in a container. The plan's next step for this, and for a real suspend/resume test, is docs/managed-runs-plan.md → «Что делать дальше». - Reservations are a budget, not measured RAM:
reserved_memory_bytessays what runs may use,observed_memory_bytessays what one run was seen using.
MCP setup: wyd mcp is read-only. wyd mcp --allow-run enables start_run
and cancel_run for that connection; start_run is described as host
execution and is never sandboxed by wyd.
WebMCP
Try the hosted demo: https://demo.wyd.sh
wyd exposes eleven WebMCP tools so a browser agent can investigate leftovers
in the same UI the human sees: list_sessions, get_session,
list_leftovers, explain_process, focus_resource, propose_cleanup, plus
managed-run reads list_runs, get_run, read_run_output, get_capacity
and the proposal-only propose_cancel_run. Nothing is killed from a tool
call — the human confirms cleanup, and run cancel goes through the same
confirmed proposal. The web can read limits and queue state but cannot change
limits or start a command.
Quick test
Paste this into a browser agent on the demo (or local wyd web):
WebMCP support was added during the OpenAI WebMCP Challenge on top of the existing wyd CLI/TUI runtime inspector.
See docs/webmcp.md.
Keys
Kill only signals the item’s own PIDs (re-checked by PID + start time). A named volume is never treated as garbage — only anonymous, unattached ones (P) are offered for pruning, with confirmation. The bottom hint line is context-aware: it shows the actions that apply to the currently selected row.
Scripts
Same snapshot as the TUI — useful after an agent finishes a task:
Filters: leftovers, mcp, agents, docker, project, sessions (JSON only).
wyd why <pid> exits 0 when the process is cleanly owned by an active
session, 1 when it is a leftover or has no recorded owner (a system source
is printed instead), 2 when the pid is not running, and 5 on an internal
error — so wyd why <pid> && … or a case $? works in scripts and CI.
wyd why <pid> --tree prints the full ancestry tree instead of the narrative:
the path from pid 1 (or the highest visible ancestor) down to the target
(marked ◀), plus the target's children (capped at 10, with a
… (+N more) line beyond that). It is a pure structure view — no provenance
needed.
wyd ports lists every listening socket as address:port, the process on it,
and what started it — the owning agent session when provenance knows it
(session opencode (active)), otherwise the system source (systemd (postgresql.service), launchd, cron, …). --json returns
{address, port, pid, process, owner_agent, owner_session, owner_state, source} per entry, omitting the fields that do not apply.
Field names stay stable until a major version bump. Empty ports / reasons / children / project are omitted.
Config
~/.config/wyd/config.toml — missing file is fine.
License
Apache-2.0. Copyright 2026 Maksym Nevinchanyy.
Source: README.md at commit fc110a6
Tools
0Version history
1- v0.10.0LatestSep 16, 2026
Score
50% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
- Reached in the last 30 days25 pts
Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.
- Auth declared10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
- Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
- DescriptionRequired15 pts
- Logo10 pts
- Documentation15 pts
- License10 pts