devenv-mcp(1)

💅 devenv-mcp — like, the whole entire manual, bestie

okay so this is devenv-mcp, and it lives in the General Commands Manual section, which is giving "official business" but honestly it's just here to help you out 🫶

✨ NAME ✨

devenv-mcp — launch the Model Context Protocol server for AI assistants 🧚

🌸 SYNOPSIS 🌸

devenv mcp [--http] [--user-config] [--from] [-o|--override-input]
[-O|--option] [-j|--max-jobs] [-u|--cores] [-s|--system] [-i|--impure]
[--no-impure] [--offline] [--nix-option] [--nix-debugger] [-c|--clean]
[-P|--profile] [--reload] [--no-reload] [--shell] [--eval-cache]
[--no-eval-cache] [--refresh-eval-cache] [--refresh-task-cache]
[--secretspec-provider] [--secretspec-profile] [--trace-to]
[-v|--verbose] [-q|--quiet] [--tui] [--no-tui] [-h|--help]

🦋 DESCRIPTION 🦋

Launch the Model Context Protocol server for AI assistants. yes literally that's the whole job and it does it slayfully ✨ your AI bestie gets a whole protocol server, no cap.

💖 OPTIONS 💖

• --http [<HTTP>] — run this as an HTTP server instead of stdio. you can optionally slide a port in there (default: 8080) 🌈
• --user-config <USER_CONFIG> — use this user configuration file instead of the XDG default. main character config file energy 👑

🎀 INPUT OVERRIDES 🎀

• --from <FROM> — the source for devenv.nix.

it can be either a filesystem path (with a path: prefix) or a flake input reference. iykyk.

Examples:

--from github:cachix/devenv
--from github:cachix/devenv?dir=examples/simple
--from path:/absolute/path/to/project
--from path:./relative/path

• -o, --override-input <NAME> <URI> — override inputs in devenv.yaml. obsessed with how clean this is.

Examples:

--override-input nixpkgs github:NixOS/nixpkgs/nixos-unstable
--override-input nixpkgs path:/path/to/local/nixpkgs

• -O, --option <OPTION:TYPE> <VALUE> — override configuration options with typed values 💅

OPTION must include a type: <attribute>:<type>. supported types are: string, int, float, bool, path, pkg, pkgs.

list types (pkgs) append to existing values by default. add a ! suffix to replace instead: pkgs! 🔥

Examples:

--option languages.rust.channel:string beta
--option services.postgres.enable:bool true
--option languages.python.version:string 3.10
--option packages:pkgs "ncdu git"       (appends to packages)
--option packages:pkgs! "ncdu git"      (replaces all packages)

🔥 NIX OPTIONS 🔥

• -j, --max-jobs <MAX_JOBS> — max number of Nix builds running concurrently. defaults to 1/4 of your available CPU cores (minimum 1). be nice to your laptop fr fr 😭
• -u, --cores <CORES> — number of CPU cores available to each build. defaults to available cores divided by max-jobs (minimum 1).
• -s, --system <SYSTEM> — override the target system. defaults to the host system (e.g. aarch64-darwin, x86_64-linux).
• -i, --impure — relax the hermeticity of the environment. letting the vibes in 🦋
• --no-impure — force a hermetic environment, overriding config. the opposite vibe check, and it wins.
• --offline — disable substituters and consider all previously downloaded files up-to-date.
• --nix-option <NAME> <VALUE> — pass additional options to nix commands.

these get passed directly to Nix using the --option flag. see man nix.conf for the full list of available options.

Examples:

--nix-option sandbox false
--nix-option keep-outputs true
--nix-option system x86_64-darwin

• --nix-debugger — enter the Nix debugger on failure. good luck bestie 🫡

🐚 SHELL OPTIONS 🐚

• -c, --clean [<CLEAN>...] — ignore existing environment variables when entering the shell. pass a list of comma-separated environment variables to let through (a lil VIP list ✨).
• -P, --profile <PROFILES> — activate one or more profiles defined in devenv.nix.

profiles let you define different configurations that can be merged with your base configuration.

see https://devenv.sh/profiles for more information.

Examples:

--profile python-3.14
--profile backend --profile fast-startup

• --reload — enable auto-reload when config files change (default). it just knows 💫
• --no-reload — disable auto-reload when config files change.
• --shell <SHELL_TYPE> — which shell to use for interactive sessions (bash, zsh, fish, nu).

Possible values:

• bash
• zsh
• fish
• nu

💜 CACHE OPTIONS 💜

• --eval-cache — enable caching of Nix evaluation results (default).
• --no-eval-cache — disable caching of Nix evaluation results.
• --refresh-eval-cache — force a refresh of the Nix evaluation cache.
• --refresh-task-cache — force a refresh of the task cache.

🍓 SECRETSPEC OPTIONS 🍓

• --secretspec-provider <SECRETSPEC_PROVIDER> — override the secretspec provider 🤫
• --secretspec-profile <SECRETSPEC_PROFILE> — override the secretspec profile 🤫

⭐ TRACING OPTIONS ⭐

• --trace-to <TRACE_TO> — enable tracing and set output destination(s). can be repeated for multiple outputs 👑

Syntax: [format:]destination

Examples:

--trace-to stderr                              # json to stderr
--trace-to pretty:stderr                       # pretty format to stderr
--trace-to json:file:/tmp/trace.json           # JSON to file
--trace-to otlp-grpc                           # OTLP gRPC to default endpoint
--trace-to otlp-grpc:http://collector:4317     # OTLP gRPC to custom endpoint

Multiple outputs:

--trace-to pretty:stderr --trace-to json:file:/tmp/t.json

Destinations: stdout, stderr, file:<path>, http(s)://<host>:<port>. Formats: json (default), pretty, full, otlp-grpc, otlp-http-protobuf, otlp-http-json.

when format is omitted, it defaults to json. tracing is disabled by default.

[env: DEVENV_TRACE_TO=] (comma-separated) [env: DEVENV_TRACE_DEFAULT_TO=] (comma-separated, used only when no explicit tracing is configured; set to empty string to suppress)

heads up bestie: that DEVENV_TRACE_DEFAULT_TO one only kicks in when you haven't configured tracing explicitly — and setting it to an empty string suppresses it entirely. no cap.

🌈 GLOBAL OPTIONS 🌈

• -v, --verbose — enable additional debug logs. the tea ☕
• -q, --quiet — silence all logs. not a single peep 💀
• --tui <TUI> — enable the interactive terminal interface (default when interactive).

Possible values:

• true
• false

• --no-tui — disable the interactive terminal interface.
• -h, --help — print help (see a summary with '-h'). yes, -h gives you the short version, the long one is the whole feast 🎀

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that's the whole page, periodt 💅 this one's from the mcp source, sitting pretty in the General Commands Manual section, and it's dated at the bottom like a lil signature — so yeah, go forth and devenv mcp, bestie. you got this 🫶✨