Platform and Distribution
Windows platform surfaces, launchers, and how fragcap ships.
npcap
A Windows packet capture driver and library, the current successor to WinPcap.
Why it matters here
npcap is not redistributable. fragcap detects it rather than shipping it,
and no distribution artifact contains it. Two non-default installation
options are required: loopback traffic capture support and WinPcap API
compatible mode. Both are verifiable from the registry, which is how
fragcap doctor names the specific missing option.
See also: Loopback
References:
- npcap project documentation, https://npcap.com. Installation options and license terms.
Game profile
A TOML file describing a game's process topology, stage match rules, and capture defaults. Versioned: every profile declares a profile schema version, and a reference to one resolves through the profile resolution order.
Why it matters here
Profiles are data, not code. They carry the same license as the repository, and a contributor can add support for a title without writing Rust. Validation reports every problem in a profile rather than stopping at the first, because the population writing these files is not the population that can debug a parser.
See also: Stage, Lifecycle class, Terminal stage, Match predicate, Ambiguous image match, Profile schema version, Profile resolution order, Duration literal
VDF
Also known as: Valve key-value format
Valve's key-value text format. Steam records library locations
(libraryfolders.vdf) and per-title metadata (appmanifest_<app_id>.acf) in
it: quoted keys, quoted-or-nested-block values, line comments, and backslash
escapes.
Why it matters here
fragcap parses the subset these two manifest kinds use with a small hand-rolled parser rather than a dependency, because the format is small and stable (specification section 16.2). A malformed manifest is reported and skipped, not fatal, so one bad file does not hide every good one.
See also: Library discovery
Library discovery
Reading Steam's local metadata to enumerate installed titles: fragcap locates the Steam installation through its Windows registry entry, reads the library-folders manifest to find every library, and reads every application manifest across them, yielding each installed title with its application identifier and install directory.
Why it matters here
Discovery reads local files and the registry only. It installs nothing, downloads nothing, and runs no Steam component, the same detection-not-bundling posture the project holds toward npcap.
See also: VDF, Profile scaffolding, Managed launch
Profile scaffolding
Generating a game profile skeleton from an installed title. fragcap scans the install directory for executable images, proposes launcher-suggestive images as launcher stages and the largest remaining image as the client, and emits a profile that passes section 15.4 validation unedited.
Why it matters here
The output is a heuristic starting point, marked as such in a header comment, and must be verified against an observed capture session: image names alone cannot tell a launcher from a client, and a title may run several processes sharing one image name. The scaffold never infers process ancestry from a static scan.
See also: Game profile, Stage, Ambiguous image match, Library discovery
Managed launch
Starting a title through Steam's protocol handler after fragcap is already watching and its capture handle is open, so every process in the launch chain produces a start event fragcap observes.
Why it matters here
Managed launch eliminates the acquisition race: a launcher whose whole lifetime
is shorter than any poll interval is still observed, because the watcher is
armed before the launch is issued. It requires game.platform and
game.app_id in the profile, and it opens no process handle (constitution
P-1).
See also: Launcher chain, Acquisition timeout, Game profile