svccat

Service catalog drift detection for multi-service repositories.

svccat reads your declared service manifest and compares it against what actually exists in the repo, flagging missing services, undeclared additions, and stale metadata before they become operational toil. It runs in your terminal and in CI, so your declared architecture stays honest.

Install

cargo install svccat

This puts a svccat binary on your PATH. (Or clone the repo and run cargo build --release; the binary lands at target/release/svccat.)

Getting started

After installing, see svccat work immediately with the built-in demo, which runs a narrated walkthrough against a throwaway sample repo (no setup, nothing touched in your own files):

svccat demo

Then point it at your own repo:

cd my-monorepo
svccat init            # scaffold services.yaml from the services already in the repo
svccat check           # report drift between the manifest and the repo

And gate CI on a clean catalog:

svccat check --fail-on-drift   # exits 1 when drift is found

Inside GitHub Actions, svccat check automatically emits inline PR annotations.

Quick start

Commands are grouped by task. Run svccat <command> --help for the full flags of any command.

Set up a manifest

• svccat init scaffolds a services.yaml from your repo (--force to overwrite), inferring each service's language and platform from files it finds on disk
• svccat import --from backstage|docker-compose|openapi seeds it from another source
• svccat lint validates the manifest for structural issues
• svccat install-hooks installs a pre-commit hook (--hook pre-push for pre-push)
• svccat completions bash prints a shell completion script (also zsh, fish)

Check for drift

• svccat check inspects drift in the current repo
• svccat check --fail-on-drift exits 1 on any drift (CI gate)
• svccat check --depth 2 also discovers services nested one level deeper
• svccat check --team platform limits the check to one team's services
• svccat check --since HEAD~1 --fail-on-new-drift exits 1 only on new drift
• svccat check --ping verifies that each service url is reachable

Add --format <fmt> to change the output, where <fmt> is one of compact, csv, json, sarif, markdown, junit, github-annotation, slack, teams, or datadog.

Fix drift

• svccat fix adds undeclared services to the manifest, inferring language and platform for each (--prune removes missing ones, --dry-run previews)

Visualize and report

• svccat graph renders a Mermaid diagram (--format dot|plantuml|markdown, --team, --filter)
• svccat report writes a full ownership and drift report (--format html, --history N, --badge)
• svccat scorecard scores each service on completeness, drift, and policy
• svccat stats prints a field-coverage summary with ASCII bar charts

Snapshots and diffs

• svccat export --format json > snap.json saves a catalog snapshot (csv also works)
• svccat diff before.json after.json compares two snapshots
• svccat snapshot save|list|delete|diff <name> manages named drift snapshots

Watch and serve

• svccat watch re-runs drift detection on every file change (--notify, --interval 30)
• svccat serve serves a live HTML report at http://localhost:7777 (--port, --refresh)

Audit, policy, and CI

• svccat audit runs lint + drift + score in one pass (add --ping)
• svccat policy checks required/recommended fields (add --fail-on-violations)
• svccat ci runs lint + drift + policy in one CI-friendly pass

Query the catalog

• svccat search auth searches by substring; svccat search team:platform by field
• svccat deps analyzes inter-service dependencies (--format mermaid|json)
• svccat tag add|remove <service> <tag> edits tags

Multiple repositories

• svccat workspace check checks drift across every repo in a [workspace] section of svccat.toml, with aggregated reporting and cross-repo dependency analysis

Manifest is auto-detected: svccat tries svccat.yaml, svccat.yml, services.yaml, services.yml in order. Most commands accept --output <file> and --format json.

Manifest format

# svccat.yaml  (or services.yaml)
version: "1"

discovery:                # optional: where to look for services
  paths: ["services/*", "microservices/*"]
  markers: [Cargo.toml, go.mod, package.json, pyproject.toml, Dockerfile]
  ignore: ["services/vendor/*"]

policy:                   # optional: fields every service must declare (error if missing)
  require_fields: [url, language, platform]

services:
  - name: api-gateway              # required
    language: Go
    platform: Cloud Run
    role: Rate-limiting reverse proxy   # required (error if missing)
    url: https://gateway.example.com    # enables --ping health checks
    team: platform                 # optional ownership
    oncall: platform@example.com
    docs: docs/api-gateway.md      # optional: warn if the file is missing
    depends_on: [auth-service]     # rendered as graph edges; validated for cycles

Declared services are matched to the repo by path:, then submodule:, then by name against discovered directories. When discovery.paths is empty, svccat tries services/*, microservices/*, apps/*, and packages/*.

Drift types

Errors and warnings both count toward --fail-on-drift.

Use it as a library

svccat ships as both a binary and a library, so you can call into the same modules the CLI uses:

use std::path::Path;
use svccat::{discovery, drift, manifest::Manifest};

let manifest = Manifest::load(Path::new("services.yaml"))?;
let discovered = discovery::discover_services(Path::new("."), &manifest);
let report = drift::analyze(&manifest, &discovered, Path::new("."));
println!("{} errors, {} warnings", report.error_count(), report.warning_count());

See examples/demo.rs (cargo run --example demo) and the API docs on docs.rs/svccat.

Learn more

• svccat <command> --help documents every command and flag.
• CHANGELOG.md for release history.
• SECURITY.md for the threat model and supported versions.

Support

svccat is free and open source. If it saves you some toil, you can buy me a coffee:

Contributing

Bug reports and pull requests welcome. Please run cargo clippy -- -D warnings and cargo fmt before opening a PR.

License

MIT. See LICENSE.