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Configuration reference

src/config.rs· 263 lines steamlogger.example.toml

SteamLogger reads exactly one TOML file. Its path is the first command-line argument, defaulting to steamlogger.toml in the current working directory.

steamlogger                       # ./steamlogger.toml
steamlogger /etc/steamlogger.toml # explicit path

The file must exist, even if every value comes from the environment. A missing file is a fatal error (exit code 1).

Keys​

KeyTypeRequiredDefaultDescription
api_keystringyes—Steam Web API key. Overridable with STEAMLOGGER_API_KEY.
steam_idinteger (unsigned 64-bit)yes—SteamID64 of the tracked account, unquoted. Overridable with STEAMLOGGER_STEAM_ID.
poll_interval_secsinteger (unsigned 64-bit)no30Seconds between polls. Effective minimum is 5 — smaller values are clamped at runtime.
output_filestring (path)no"steamlog.json"Where the JSON log is written. Relative paths resolve against the working directory.
enrichbooleannotrueCollect friends / lobby / server+map data. false logs only name, start and end.

Unknown keys are ignored, not rejected — a typo like poll_intervals_secs silently leaves the default in place. Grep your config against the table above if a setting seems to have no effect.

The complete example file​

This is steamlogger.example.toml, reproduced verbatim (the same text is available programmatically from config::example_config()):

steamlogger.example.toml
# SteamLogger example configuration.
# Copy this file to `steamlogger.toml` next to the binary and edit the values.

# Steam Web API key. Required.
# Get one at https://steamcommunity.com/dev/apikey
# May be overridden by the STEAMLOGGER_API_KEY environment variable.
api_key = "YOUR_STEAM_API_KEY"

# Numeric SteamID64 of the tracked user. Required.
# Find yours at https://steamid.io or in your Steam profile URL's vanity lookup.
# May be overridden by the STEAMLOGGER_STEAM_ID environment variable.
steam_id = 76561198000000000

# Seconds between polls of the Steam API. Optional, defaults to 30.
poll_interval_secs = 30

# Path of the JSON log file written by the app. Optional, defaults to "steamlog.json".
output_file = "steamlog.json"

# Whether to collect friends/lobby/map enrichment data. Optional, defaults to true.
enrich = true

Environment variables​

VariableOverridesBehaviour
STEAMLOGGER_API_KEYapi_keyUsed when set and non-empty. An empty value falls back to the file.
STEAMLOGGER_STEAM_IDsteam_idUsed when set at all. Must parse as an unsigned 64-bit integer (surrounding whitespace is trimmed) — otherwise startup fails.

The two variables behave slightly differently on purpose, and the asymmetry is worth remembering:

STEAMLOGGER_API_KEY="" steamlogger     # ok: falls back to api_key in the file
STEAMLOGGER_STEAM_ID="" steamlogger    # error: "" is not a valid u64

Precedence​

In short: environment beats file, file beats default, and the two required keys must be resolved from somewhere.

Validation and error messages​

config::load fails fast with a contextual message; main prints it to stderr together with a hint and exits with code 1.

SituationMessage (abridged)
Path does not exist or is a directoryconfig file not found: <path> (see steamlogger.example.toml for a commented example)
File unreadable (permissions)failed to read config file <path>
Not valid TOMLinvalid TOML in config file <path>
STEAMLOGGER_STEAM_ID not a numberSTEAMLOGGER_STEAM_ID must be a valid u64
No api_key anywheremissing required config key `api_key` (set it in steamlogger.toml or via STEAMLOGGER_API_KEY)
No steam_id anywheremissing required config key `steam_id` (set it in steamlogger.toml or via STEAMLOGGER_STEAM_ID)

Anything that is not a config problem — a failing poll, an unreachable game server, a log write error — is reported on stderr and the loop keeps running. See Resilience.

Worked examples​

Minimal file, secrets from the environment​

steamlogger.toml
poll_interval_secs = 15
output_file = "/var/lib/steamlogger/steamlog.json"
export STEAMLOGGER_API_KEY=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
export STEAMLOGGER_STEAM_ID=76561198000000000
steamlogger /etc/steamlogger/config.toml

Lightweight mode (no enrichment)​

Only one Steam API call per tick, no UDP traffic, and the log keeps just name, start and end:

steamlogger.toml
api_key = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
steam_id = 76561198000000000
enrich = false

Several accounts on one machine​

Run one process per account, each with its own config and output file:

alice.toml
api_key = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
steam_id = 76561198000000001
output_file = "/var/lib/steamlogger/alice.json"
steamlogger /etc/steamlogger/alice.toml &
steamlogger /etc/steamlogger/bob.toml &

Never point two processes at the same output_file: both rewrite the whole file every tick and the last writer wins.

Choosing output_file​

  • Absolute paths are the safe choice for anything run by a service manager, where the working directory is not what you expect.
  • Parent directories are created automatically on the first write.
  • A bare filename (steamlog.json) or an absolute path both work in all cases. A relative path containing a directory (logs/steamlog.json) hits a known edge case in the atomic-write helper — see storage::write_log → Known edge case.

:::warning Protect the file steamlogger.toml contains a credential. On Unix:

chmod 600 steamlogger.toml

Both steamlogger.toml and steamlog.json are already in the repository .gitignore. :::