cli

Fountain CLI (Go)

Single-binary port of the Fountain CLI from Elixir/Burrito to Go. Same command surface, same API contract, same ~/.fountain/credentials file.

Why a port

The CLI is an HTTP/JSON client with subprocess shellouts (1Password, Bitwarden Secrets Manager, Infisical) and an SSE stream consumer. None of that needs the BEAM. Burrito wraps Elixir releases in a Zig-built launcher so the BEAM ships inside the binary; that pipeline has been fragile (Zig version pinning, slow startup, large binaries) and the runtime concurrency model adds nothing for a CLI.

The Go binary is ~10 MB, statically linked, starts in <50 ms, and cross-compiles cleanly with stdlib tooling.

Build

Requires Go 1.26+.

cd cli
go build -o fountain ./cmd/fountain
./fountain --help

Cross-compile:

GOOS=linux  GOARCH=amd64 CGO_ENABLED=0 go build -o fountain-linux-amd64  ./cmd/fountain
GOOS=linux  GOARCH=arm64 CGO_ENABLED=0 go build -o fountain-linux-arm64  ./cmd/fountain
GOOS=darwin GOARCH=amd64 CGO_ENABLED=0 go build -o fountain-darwin-amd64 ./cmd/fountain
GOOS=darwin GOARCH=arm64 CGO_ENABLED=0 go build -o fountain-darwin-arm64 ./cmd/fountain

The cli-release-go.yml workflow builds and attaches all four to the GitHub release on tag push.

Layout

cli/
  cmd/fountain/         entry point
  internal/
    api/                HTTP client (Bearer auth, JSON, error envelope)
    cmd/                Cobra command tree (auth, keys, env, agent, vault, conv, run, apply)
    config/             API key + base URL precedence resolver
    credentials/        ~/.fountain/credentials reader/writer (TOML-ish)
    manifest/           YAML doc reader for `apply`
    output/             table + JSON rendering helpers
    secrets/            external secret resolvers (op, bws, infisical)
    sse/                RFC 6202 Server-Sent Events parser
    substitution/       ${VAR} expansion (with $${VAR} escape)

Test

go test ./...

Coverage focuses on the pure logic — credentials parser, substitution, SSE framing, manifest loading. Command handlers (which only assemble HTTP requests) are validated by smoke runs against a real server.

History

This binary replaced the Elixir/Burrito CLI that previously lived at apps/fountain_cli/. The ${VAR} substitution module the server still needs at provision time was moved into the server app, and has since become the library Managoat.Substitution in apps/managoat_substitution (decisions/0037); everything else was deleted. internal/substitution here is the Go implementation of the same syntax and the two are kept aligned.

The up / down self-deploy commands were removed before the Go port and are not reintroduced.

Install

Pre-built binaries are attached to each GitHub release:

# macOS arm64
curl -L -o fountain https://github.com/managoat/fountain/releases/latest/download/fountain-darwin-arm64
chmod +x fountain && sudo mv fountain /usr/local/bin/

# Linux amd64
curl -L -o fountain https://github.com/managoat/fountain/releases/latest/download/fountain-linux-amd64
chmod +x fountain && sudo mv fountain /usr/local/bin/

Pinned versions are at https://github.com/managoat/fountain/releases/download/<tag>/fountain-<os>-<arch>.

Streaming long turns

fountain run, fountain conv prompt and fountain conv stream follow a conversation until the turn reaches a terminal state.

The server closes an SSE connection after 60 seconds of quiet, so a turn that thinks for a while without emitting output will see the connection drop. The CLI reconnects using Last-Event-ID, so anything produced while disconnected is replayed rather than lost, and a dropped connection is never mistaken for a finished turn.

If nothing arrives at all for 30 minutes the CLI gives up with an explicit error naming the conversation, rather than exiting successfully. Override the wait with FOUNTAIN_STREAM_IDLE_TIMEOUT (seconds):

FOUNTAIN_STREAM_IDLE_TIMEOUT=7200 fountain run researcher -p "audit the auth module"

Reattach to a conversation at any time — nothing is lost by disconnecting:

fountain conv stream <conversation-id>