SlopCop

Static analysis deep enough for CI, fast enough to run on every edit.

slopcop sends one git patch, from the base commit to the working tree, to the hosted check API at https://slopcop.com. The service applies it, runs the hosted policy catalog plus the repository rules you selected, and returns the report: every finding with its severity, the file and line that triggered it, and the certainty behind it. The analysis is Bifrost, an open-source static analysis engine rather than a language model, so a finding traces back to a rule instead of to a guess.

There is no local analyzer and nothing to install per language: the CLI ships the change and prints what comes back, and it never decides on its own that there is nothing to check. The command is built for agents and one-shot CI: no prompts, one request, and the analyzer's exit contract.

Install

npm, PyPI, the release archive, and the shell and PowerShell installers all install the same release binary for macOS, Linux, and Windows on x64 and arm64, so slopcop version reports which release it came from. The Go toolchain can build that binary from source instead.

npm

npm install --global @brokkai/slopcop
slopcop --help

The tarball carries the release binary for every supported platform, so it needs no Go toolchain. npx @brokkai/slopcop runs it without installing it.

PyPI

pip install brokk-slopcop

pipx install brokk-slopcop or uv tool install brokk-slopcop puts it in an environment of its own. The wheels carry the release binary, so no Go toolchain is needed either. The package is brokk-slopcop because PyPI already has an unrelated project named slopcop; the command it installs is still slopcop, and python -m brokk_slopcop runs the same binary.

Release archive

Each release publishes slopcop_v<version>_<os>_<arch>.tar.gz (.zip on Windows) holding the binary, README.md, and LICENSE, plus a checksums.txt covering every archive. Download them from https://github.com/BrokkAi/slopcop/releases/latest and check the sha256 before unpacking:

ver=0.0.3; os=linux; arch=amd64   # darwin/arm64 on Apple silicon
base=https://github.com/BrokkAi/slopcop/releases/download/v$ver
curl -fsSLO "$base/slopcop_v${ver}_${os}_${arch}.tar.gz"
curl -fsSLO "$base/checksums.txt"
grep "${os}_${arch}" checksums.txt | sha256sum -c -   # shasum -a 256 -c - on macOS
tar -xzf "slopcop_v${ver}_${os}_${arch}.tar.gz" slopcop
sudo install -m 755 slopcop /usr/local/bin/slopcop

Shell installer

curl -fsSL https://raw.githubusercontent.com/BrokkAi/slopcop/master/install.sh | sh

It takes the latest release, verifies the archive against checksums.txt, installs slopcop to $HOME/.local/bin, and adds that directory to the shell profile. SLOPCOP_VERSION, SLOPCOP_INSTALL_DIR, and SLOPCOP_NO_MODIFY_PATH override its defaults.

PowerShell installer

irm https://raw.githubusercontent.com/BrokkAi/slopcop/master/install.ps1 | iex

It takes the latest release, verifies the archive against checksums.txt, installs slopcop.exe to %LOCALAPPDATA%\Programs\slopcop, and adds that directory to the user Path. SLOPCOP_VERSION, SLOPCOP_INSTALL_DIR, and SLOPCOP_NO_MODIFY_PATH override its defaults.

Upgrade notice

Every response from the service names its newest release in the SlopCop-Latest-Version header. When that is newer than the running build, the CLI prints one line on stderr, never stdout, so --format json and sarif stay clean:

slopcop v0.0.9 is available (you have v0.0.7). Upgrade: npm install --global @brokkai/slopcop@latest

The command follows the channel the binary was installed through (npm, npx, pip, pipx, or uv), judged by where it lives, and links back here otherwise. The notice prints at most once a day; the time of the last one is kept in slopcop/update-notice next to the config. dev builds, Stop hook runs, and runs with $SLOPCOP_NO_UPDATE_NOTICE set to any non-empty value never print it. A service that no longer accepts a version answers client_outdated (HTTP 426), which exits 2.

Go

go install github.com/BrokkAi/slopcop/cmd/slopcop@latest

Go 1.25 or newer is required to build. A plain go install reports dev as its version; in a clone, make install stamps the version from git describe.

Enable it in an agent

The binary carries the agent skill that teaches a coding agent how to run slopcop, plus an automatic check hook for Claude Code and Codex. slopcop init installs the skill into each well-known skills directory whose harness is present, and names what it did:

A skill that is already there is left alone by init, so running it again is safe. slopcop login and every check also install the skill in those directories, rewriting one that differs from the skill bundled into the binary, so an agent follows the instructions of the slopcop version it runs. Each install records the version that wrote it, and what each file held, in .slopcop-skill.json in the skill folder. An update names the version it replaces, the new one and the files that changed, for example:

slopcop: updated the slopcop skill at ~/.claude/skills/slopcop from v0.0.9 to v0.0.10 (changed: SKILL.md). Reread it if you loaded the old one.

It removes the files the new skill no longer has. A skill with local edits, one that matches neither its record nor any release, is copied first to skill-backups/<harness>-<time> next to the slopcop configuration, outside every skills directory so no harness loads it as a second skill, and the notice says where. A check's json and sarif reports carry the same update (see below). slopcop init --no-skill skips the install and any update of it.

Init also adds a Stop hook for each harness installed here, and leaves everything else in the file as it was:

Codex runs a new or changed hook only once you trust it: open Codex and review it with /hooks. Init never writes that trust itself, and reminds you each time it runs, since Codex says nothing of a hook it skips. The hook stays the same from one release to the next, so an update does not ask for it again.

When the agent stops, the hook checks the working tree through the same hosted API, but only when all of these hold:

• the session wrote files in the repository with its edit tools (a Codex session's subagents included), or the working tree has a changed dependency manifest or lockfile (see below);
• slopcop is signed in, and the workspace a check would use ($SLOPCOP_WORKSPACE, or the login's) has the repository active (slopcop repo list), so nothing is sent from other repositories;
• the tree differs from the last check in the session, including a check the agent ran by hand.

An agent often adds a dependency through its shell, with npm install, pnpm add, cargo add or uv add, which no edit tool records. So the hook also checks when git shows one of these files changed, added or untracked in any directory of the repository: package.json, package-lock.json, npm-shrinkwrap.json, pnpm-lock.yaml, yarn.lock, Cargo.toml, Cargo.lock, pyproject.toml, uv.lock, poetry.lock, requirements*.txt, go.mod and go.sum. Files git ignores and those under node_modules do not count. The hook recognises these files by name only: it never reads them, runs a package manager or asks an advisory database; the hosted check reads them like any other file in the change. A changed dependency file counts as one the session wrote, since the hook cannot tell which command changed it, so its new findings are handed to the agent like those in files it edited, even if the file was already changed when the session began.

New findings in files the session wrote are handed to the agent to fix, once for a given tree and at most twice in a row; then the agent is let go and you are told what remains. A finding ignored with slopcop ignore is not handed back. New findings in other files on the branch are only mentioned. The hook never keeps the agent going on its own failures: a refusal the service calls final, such as an expired login, is reported once and the hook stays quiet for the rest of the session, until a check by hand completes; a brief outage is only reported. The hook runs as slopcop hook claude || true (and slopcop hook codex || true, or || exit /b 0 under Windows' cmd), so even a slopcop that cannot run it, such as an older one first on PATH, lets the agent stop; init warns when that is the case, because no check would run.

Use slopcop init --no-hooks to install only the skill, or slopcop init --remove-hooks to remove SlopCop's hooks and nothing else. Ordinary checks do not reinstall a removed hook. The skill remains the way to check from other harnesses.

Sign in

slopcop login                           # browser device flow
slopcop login --token "$SLOPCOP_TOKEN"  # existing credential, for CI and agents

The browser flow prints a link that opens the approval page with the code filled in, plus the page and code to type in instead, and stores the token once the login is approved. Approve only if the page shows the code your terminal printed. The service URL defaults to https://slopcop.com; --service, $SLOPCOP_SERVICE, or a stored value override it.

The credential lives in slopcop/config.json under the user config directory and is written owner-only. slopcop logout clears it.

Precedence:

Workspace and repositories

A login runs its checks and ignores in, and bills, one workspace: the one active in the browser when the login was approved.

slopcop whoami                     # account, this login's workspace, its plan, the service URL
slopcop workspace list             # the account's workspaces; * marks this login's
slopcop workspace use "Acme team"  # move this login (not the browser) to another, by name or id
slopcop check -w "Acme team"       # check in, and bill, another workspace this once
slopcop repo list                  # the workspace's repositories: active, disabled, or over the limit
slopcop repo disable acme/widgets  # stop checking and charging for one (owner only)
slopcop repo enable acme/widgets   # turn it back on, within the workspace's active limit

whoami, workspace list and repo list take --format human|json, as do workspace use and repo enable|disable for their answer. Every active repository after a workspace's first costs credits every 30 days; a disabled one is not checked or charged and keeps its reports, findings and settings. repo enable and repo disable ask you to type the repository's owner/name and refuse when stdin is not a terminal: an agent or CI job runs with your login, and the service cannot tell it from you, so changing what the workspace pays stays a step you take yourself. workspace use moves every agent and script using this login, not only the one that runs it, so it asks [y/N] and refuses when stdin is not a terminal. To check in another workspace without moving anyone, check, ignore and repo take -w/--workspace <name|id> (or $SLOPCOP_WORKSPACE) for that one command; the login stays where it was. Give agents that share a login their own --workspace instead of switching it.

Names match without regard to case; when two workspaces share a name, or two providers a repository name, pass the id the listing prints. There is no repo add: a first check adds a repository. When the workspace would then pay for it (it already has an active repository and is charged), the service refuses the check with repository_add_unconfirmed until a person confirms: at a terminal check prints what it costs, asks Add owner/name to "Workspace"? [y/N], and on a yes sends the check again and says added owner/name to "Workspace" on stderr. With no terminal, as for an agent or CI (a pipe or the null device is not one), nothing is asked: the check exits 4 with the service's remedy, a line naming the command that confirms it, and, in json, a failed report naming the code. A no at the terminal ends the same way. Once the person has approved it, check --add-repository --workspace <name|id> confirms without a terminal; the flag needs --workspace (the flag itself, not $SLOPCOP_WORKSPACE), so an approval given for one workspace cannot add the repository to the one the login happens to point at. The flag changes nothing for a repository already in that workspace. A workspace's first repository is added without asking. Deleting repositories, archiving workspaces, members, credits and repository settings stay in the web app. The commands exit 0 on success and 2 with the service's message and remedy otherwise, as ignore does.

Check

slopcop                          # check the change in the current checkout
slopcop check --format json      # same, machine-readable
slopcop --root ../repo --base origin/main

The base commit defaults to the merge base with the branch upstream, then the merge base with origin/HEAD, then HEAD when neither is known. When the upstream merge base yields an empty patch, as on a branch whose commits are all pushed, the CLI uses the merge base with origin/HEAD instead, so a check right after a push still covers the branch. --base REV names the branch the change started from and, like git diff REV...HEAD, uses the merge base of REV and HEAD, so commits that landed on REV after the branch point are not sent as reverse edits. --base-exact REV diffs against REV itself. The service must already have the base commit in its clone; a missing one comes back as the service's base_not_found message and remedy. The CLI then asks origin for its default branch (git ls-remote, no prompt, 10 second limit) and adds a line when the clone explains the failure: origin's default branch was renamed and origin/HEAD still names the old one, or the base is not on origin's default branch.

Every run sends one check request, even when the working tree matches the base and the patch is empty. A clean result or a failure always comes from the service. A report for an empty patch comes with a note on stderr that suggests --base, and json adds "emptyChange": true (sarif: properties["slopcop.emptyChange"]): a clean result then means nothing changed was checked.

Flags:

What is sent

One git patch from the base commit to the working tree. An empty change is sent as an empty patch, not filtered out. The patch carries committed but unpushed work, unstaged edits, untracked files, deletions, renames, mode changes, and binary content. Git-ignored files stay out, except selected .slopcop/policies rules, which must travel because the service evaluates them from the patched checkout.

A check run by a Claude Code or Codex agent also sends which models wrote the change, so the service can tie each finding to the model that wrote its file. The CLI finds the agent's session from its environment and reads that session's own record:

• Claude Code: CLAUDE_CODE_SESSION_ID names the transcript under ~/.claude/projects (or $CLAUDE_CONFIG_DIR/projects), subagents included. Each successful Write, Edit, MultiEdit or NotebookEdit gives a model, an effort and a file.
• Codex: CODEX_THREAD_ID names the rollout under ~/.codex/sessions (or $CODEX_HOME/sessions). Each completed file change gives the files, and its turn gives the model and effort. A move counts as writing its destination.

It reads only those fields, never the conversation, tool input or file contents. What it sends is the harness, its version, the session id as an opaque identifier, and each model and effort with the repository-relative files it wrote. A check run outside an agent session sends none of this. It is analytics only, asserted by the client, and never decides a check. --verbose prints it.

The service owns the limits on what a check accepts. When a change is too large or touches too many files, the service's payload_too_large response is printed verbatim; the CLI does not impose its own limits.

Every check also runs the hosted catalog. Rules under .slopcop/policies/**/*.rqlp are added automatically unless --no-policy-discovery is set.

New and pre-existing findings

A check fails only on findings the change introduced or touched: the service marks a finding new when it is in a file the change writes and its lines meet a line the change added, or the line beside one it removed. Findings that were already in the code are counted (summary.existingFindings, and N already in the code in the human summary), never fail the check, and are not listed. A change that introduces nothing exits 0, however many findings the repository already holds. --show-existing is deprecated and hidden: the service no longer sends those findings, so against it the flag lists nothing (a service from before that still gets them listed), and it stays so that scripts passing it keep running.

Ignore a false positive

Each finding a check reports carries an id. When a finding is a false positive, ignore it:

slopcop ignore 0f8fad5b-d9cb-469f-a165-70867728950e

That finding is not reported again for this repository. Ignoring covers that one finding, its rule plus its place in the code, in its repository for your workspace; the rule keeps reporting everything else. Ignoring a finding twice is fine. ignore uses the same login and service URL as a check, exits 0 with a one-line confirmation, and otherwise exits 2 with the service's message and remedy; finding_not_found means the id is unknown or comes from a check outside your workspace.

Output and exit codes

The service answers structured data; the CLI renders it. human prints one block per new finding, with an ID: line when the service names one, then a summary line such as 1 new finding across 1 file(s); 72 already in the code | Analysis complete, and any omitted new findings or incomplete checks. json prints status, baseCommit, summary (newFindings and existingFindings count the split), findings (each with new and its id), incomplete, inconclusive, failure when the analysis did not complete, and emptyChange when the patch was empty. When the check installed or updated the skill, skillUpdated lists each skill directory it wrote: dir, from (a release, unknown, or absent for a fresh install), to, changed and, for a skill with local edits, backup; the failed and pending reports carry it too, and sarif puts it in properties["slopcop.skillUpdated"]. sarif prints a SARIF 2.1.0 log whose results carry baselineState new and the finding id in properties["slopcop.findingId"]. --format only changes the rendering, never the request, so the service answers the same check whichever is used.

Only clean exits 0: a status this CLI does not know exits 2, so a newer service can never pass a check by accident, and stderr names the status. An interrupted check prints no report. Interrupted before it was sent, nothing reached the service; after, a service that received it keeps running it, and running the same check again picks up its result.

An inconclusive check, one that ran but could not prove there is nothing more to find, never changes the exit code or the status. Complete proof is rare in static analysis, typically at a library boundary, so this is the norm rather than a gap. Each report still says where they are, so a reviewer can judge what a clean result is worth: human prints one Inconclusive: line with the count and how many concern only files the change does not write, and --verbose names each check. json lists them in inconclusive, each with policyId, reason and elsewhere (true when it concerns only files the change does not write), beside the summary.inconclusive count. sarif adds a note notification per check with slopcop.inconclusive and slopcop.elsewhere properties. The service names at most 50; the counts cover the rest. It does not yet say which files or lines each one concerns, or what evidence was missing. A check that timed out or that Bifrost judged unreliable is incomplete and counts wherever it is.

The service applies --fail-on and sets the status; the exit code follows it. The CLI always sends --fail-on, defaulting to finding: a check fails only on findings the change introduced, so any of them, a note or an unrated one included, is worth fixing before the change lands. The service's own default for a request without failOn is Bifrost's warning; pass --fail-on warning to match it. New findings that cross --fail-on exit 1 even when some check did not complete.

While the service answers check_running, the CLI waits the Retry-After it names and asks again until --timeout runs out; every ask attaches to the same running check. If it is still running then, the CLI exits 3, prints the service's message and remedy on stderr, and in json prints {"status": "pending", "retryAfter": 5, "message": …, "remedy": …} on stdout (sarif prints a run with slopcop.status pending). Running the same check again picks up the same analysis.

Service failures print the closed contract exactly: message, remedy, and any install URL. The codes, messages, and remedies are defined by the service in server/src/check.rs of BrokkAi/bifrost-service; the CLI does not rewrite them. The remedies name no client, so the CLI adds its own command after some: slopcop login when the remedy is to sign in, the listing to choose from after workspace_not_found or workspace_repository_not_found, and slopcop whoami after repository_disabled, since the workspace that disabled it is the one this login is bound to, --workspace after owner_required, and --add-repository --workspace "Name", with the workspace the check would have added the repository to, after repository_add_unconfirmed. A failed check exits 4 when only a person can clear the refusal (auth_required, auth_expired, account_required, repo_not_indexed, app_not_installed, app_no_repo_access, gitlab_not_connected, no_access, insufficient_credits, repository_disabled, repository_add_unconfirmed, workspace_repository_limit_reached, active_repository_limit_reached, owner_required, and browser_required), so a script can stop instead of retrying, and 2 otherwise. Stderr starts with the code, as in slopcop: repository_add_unconfirmed: …. human prints nothing on stdout; json prints {"status": "failed", "code": …, "message": …, "remedy": …, "retryable": …}, plus installUrl or topUpUrl when the service sent one; sarif prints a run with slopcop.status failed, whose invocation is unsuccessful and carries an error notification whose descriptor id is the code.

API

The CLI calls POST <service>/v1/check with a bearer token:

{
  "repoUrl": "https://github.com/owner/name",
  "baseCommit": "0123456789abcdef0123456789abcdef01234567",
  "change": "<base64 git patch>",
  "selection": {"files": [".slopcop/policies/rule.rqlp"]},
  "failOn": "finding",
  "addRepository": true
}

addRepository is sent only after a person confirms adding the repository, at the terminal or with --add-repository. The service rejects any other field. With --workspace, every request, the check's, the ignore's and the account routes', carries the workspace's id in the SlopCop-Workspace header; a name is first looked up with GET <service>/v1/whoami. The response carries status, baseCommit, applied, summary, findings, incomplete, and failure when the analysis did not complete. Against a service from before findings were marked new, the CLI treats every finding as new, as that service gated on all of them. Non-2xx responses carry code, message, remedy, retryable, and an optional installUrl.

Each finding in the response carries an id; a service from before findings could be ignored omits it.

slopcop ignore <id> calls POST <service>/v1/ignore with the same bearer token and {"findingId": "<id>"}, and gets back {"findingId": "<id>", "status": "ignored"}. Failures use the same closed contract, including finding_not_found.

The account commands use the same bearer token. GET <service>/v1/whoami answers account, workspace (id, name, kind, role, current), plan (pro or free) and workspaces. POST <service>/v1/workspace with {"workspaceId"} rebinds the login. GET <service>/v1/repositories answers repositories (id, provider, fullName, enabled, active) with activeRepositoryLimit, activeRepositories and canManageRepositories, and POST <service>/v1/repositories/state with {"repositoryId", "enabled"} answers {repositoryId, fullName, enabled, active}. Their failure codes add account_required, workspace_not_found, workspace_repository_not_found, owner_required and browser_required (a private Bitbucket or GitLab repository, which only the web app can change) to the check's.

slopcop login uses the device flow: POST /api/device returns a deviceCode, userCode, verificationUri, expiresIn, and interval, and POST /api/token returns 202 while pending or 200 with a token once approved. The failure codes are slow_down, which raises the polling interval, expired_token, access_denied, and device_flow_disabled. A failure the service marks retryable, such as rate_limited or service_unavailable, keeps the code valid, and so do a dropped connection and a proxy's 429, 502, 503 or 504 without a code: login waits the Retry-After, or the interval if that is longer, and polls again until the code expires.

Development

make test        # go test ./...
make vet         # go vet ./...
make build       # bin/slopcop-<goos>-<goarch>
make cross-check # linux, darwin, and windows on amd64 and arm64
make npm-test    # node --test npm/test
make wheels      # pypi-dist/, one wheel per release target

Releases are tag-driven. Pushing a v*.*.* tag runs GoReleaser, which builds linux, darwin, and windows for amd64 and arm64, packages tar.gz archives (zip on Windows) with checksums.txt, and publishes the GitHub release. .goreleaser.yaml is the single source of truth; CI runs goreleaser check and a snapshot build on every change, and make release-check runs the same locally when GoReleaser is installed. The same tag push then packs @brokkai/slopcop from those release archives and publishes it to npm with trusted publishing, so the package needs no npm token.

The same tag also packs a wheel per release target from the binaries GoReleaser just built, installs the wheel for every platform GitHub can run, and publishes brokk-slopcop to PyPI with trusted publishing, so that package needs no PyPI token either.

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