MiniMax | shunt

Route MiniMax-M3 (1M context) to MiniMax's Anthropic-compatible endpoint with a MINIMAX_API_KEY.

MiniMax serves its models over an Anthropic-compatible endpoint — shunt forwards Claude Code’s Messages request as-is and injects the MiniMax API key. There is no built-in preset, so the upstream declares kind and base_url explicitly.

Quick start

Let a coding agent wire it up for you — for a provider without a named blueprint, shunt add injects the documentation URL into its generic research guide (offline and read-only; the agent edits the config, the command never does):

shunt add upstream https://platform.minimax.io/docs/token-plan/claude-code --print | claude

Or follow the manual steps below.

Configure the upstream

[[upstreams]]
name = "anthropic"
provider = "anthropic"   # keep Anthropic as the default for unrouted models (e.g. claude-*)

[[upstreams]]
name = "minimax"
kind = "anthropic"
base_url = "https://api.minimax.io/anthropic"
auth = { mode = "api_key", env = "MINIMAX_API_KEY" }

[[routes]]
model = "MiniMax-M3"
provider = "minimax"

Ordered [[upstreams]] replace shunt’s built-in providers, so the config must declare the anthropic default it still falls back to (server.default_provider defaults to anthropic).

The legacy [providers.minimax] table form remains supported — but do not mix [[upstreams]] and [providers.*] in one file.

Credentials

export MINIMAX_API_KEY='...'

Never write the key into the config. shunt check validates the config’s structure but does not read the key’s value — if MINIMAX_API_KEY is unset, the first request routed to minimax returns an authentication error.

Models

Model id	Notes
`MiniMax-M3`	1M-token context; a client may append Claude Code’s `[1m]` marker (`MiniMax-M3[1m]`, the slug MiniMax’s own Claude Code integration documents) — shunt strips it before matching, so route the unsuffixed id

Select the routed id in Claude Code via ANTHROPIC_MODEL, ANTHROPIC_CUSTOM_MODEL_OPTION, or a subagent’s model: frontmatter. To surface an entry in the /model picker instead, advertise a claude-prefixed alias with a [models.upstream_model] map — see Model Discovery. A mapped id must not end in [1m] — clients strip the hint before matching, which also makes a [[routes]] entry keyed on MiniMax-M3[1m] unreachable, so always route the unsuffixed MiniMax-M3.

Verify

shunt check    # -> config ok
shunt run
curl -sS http://127.0.0.1:3001/v1/messages \
  -H 'anthropic-version: 2023-06-01' \
  -H 'content-type: application/json' \
  -d '{"model":"MiniMax-M3[1m]","max_tokens":16,"messages":[{"role":"user","content":"Reply with OK."}]}'

Confirm the response’s x-gateway-upstream header names minimax, then point Claude Code at shunt.

Subagent plugin

The shunt-minimax plugin ships a ready-made Claude Code subagent for the model above:

/plugin marketplace add pleaseai/shunt
/plugin install shunt-minimax@shunt