Module config 

TOML configuration.

One file per repository, conventionally drep.toml at the root. The shape is deliberate: every field has a documented default, so a partial file works. Missing keys are not an error - the section just inherits the default. Providers are declared as [[llm]], an ordered array of tables: a preference order, tried head first, each enabled entry a fallback for the one before it.

The two things this module owns that are not obvious from the field list:

• ${VAR} expansion. An api key (or any string value) can name an environment variable instead of holding the secret. The file gets committed; the secret does not. An unset variable is an error rather than an empty string, because a silent empty credential produces a confusing 401 instead of a clear “API_KEY is not set”.
• max_tokens defaults to None, meaning no cap is sent to the model. Modern reasoning models ship 256k-1M context, and inventing a ceiling truncates them mid-thought. The option stays available for capping spend.

The second layer

This file is per-repository and drep init gitignores it, so a control written here is per-developer and opt-in. site is the layer above it: a machine-level policy file a checkout can tighten but never loosen.

load and validate know nothing about it and take no site argument. The clamp is applied by the caller, after load returns, which is what keeps ConfigError a statement about this file alone - every one of its messages numbers [[llm]] entries in this file’s order, and a bare #2 that could mean either file is exactly the ambiguity those messages exist to avoid.

Modules

site

The machine-level site policy layer above drep.toml.

Structs

Config

The whole configuration tree, rooted at the file.

LlmConfig

One provider in the failover chain.

Enums

BackendKind

Which implementation serves one provider entry.

ConfigError

What went wrong reading or validating the configuration.

ReasoningEffort

Reasoning effort accepted by the Codex CLI configuration contract.

Constants

DEFAULT_MAX_REVIEW_ROUNDS

Functions

default_config_path

The conventional config file location: drep.toml in the current directory.

env_var_refs

Every ${NAME} reference in s, in the order they appear.

env_var_refs_in

Every ${NAME} reference in any string value of a parsed TOML tree.

load

Load and validate path.

parse_protocol

Parses a protocol = value, or None when it names nothing the SDK speaks.

required_env_var_refs

Every ${NAME} reference that super::load will actually try to substitute.