pi-byteplus-modelark-provider

A Pi extension that registers your BytePlus ModelArk Coding Plan subscription as a model provider in Pi.

One API key covers the whole plan — Seed, GLM, Kimi, DeepSeek and GPT-OSS — and the model list is discovered from BytePlus rather than hardcoded, so new plan models appear without waiting for an extension release.

If you have used pi-byteplus-modelark, this is the same idea with two changes you might care about:

• No export BYTEPLUS_API_KEY=… in your shell profile. You sign in with Pi's own /login, and the key is stored in ~/.pi/agent/auth.json.
• No hand-maintained model list. The extension reads the model list BytePlus publishes for the Coding Plan, layers in context/output limits, and falls back gracefully when BytePlus changes that page.

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Requirements

• Pi 0.85.x or newer.
• Node 20 or newer (what Pi itself requires).
• A BytePlus ModelArk Coding Plan subscription. The Coding Plan endpoint rejects a pay-as-you-go-only key.

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Quickstart

1. Install

From npm:

pi install npm:pi-byteplus-modelark-provider

Or straight from git, pinned to a tag:

pi install git:github.com/jstokke/pi-byteplus-modelark-provider@v0.1.0

Or over HTTPS:

pi install https://github.com/jstokke/pi-byteplus-modelark-provider@v0.1.0

Already have the old pi-byteplus-modelark installed? Remove it first — both register a provider, and the old one pins a stale model list:

pi remove npm:pi-byteplus-modelark

2. Sign in

Get an API key from the BytePlus ARK console (region ap-southeast-1), then inside Pi:

/login byteplus

Pi prompts with a masked secret input, checks the key, and saves it. You only do this once.

3. Pick a model

/model

You should see the current Coding Plan line-up under BytePlus ModelArk, for example byteplus/glm-5.2, byteplus/kimi-k2.5, byteplus/deepseek-v4-pro, or byteplus/ark-code-latest for the plan's auto-router.

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What it does

Provider id	byteplus
Display name	BytePlus ModelArk
Endpoint	https://ark.ap-southeast.bytepluses.com/api/coding/v3 (Coding Plan)
Wire	OpenAI Chat Completions
Auth	Pi /login (masked prompt → auth.json), env vars as fallback

• Uses the Coding Plan endpoint, so requests consume your subscription instead of being billed on top of it.
• Discovers the plan's models from the list BytePlus publishes, cached 24h, with the live /models catalog as a metadata source and fallback, and ten known-good ids bundled as a last resort.
• Knows each model's limits — context window, output cap, vision and reasoning support — instead of shipping every model as "128k, text only".
• Sends reasoning correctly. ModelArk accepts reasoning_effort (none | minimal | low | medium | high | xhigh | max), so Pi's thinking picker actually works, and glm-5.2 gets the extra off/xhigh levels BytePlus documents for it.
• No runtime dependencies. Plain Node built-ins; the HTTP surface is fully mocked in tests.

Managing it

pi update --extensions   # update, whichever source you installed from
pi remove npm:pi-byteplus-modelark-provider
pi remove git:github.com/jstokke/pi-byteplus-modelark-provider

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Alternatives and escape hatches

Headless / CI setups can skip /login and use an environment variable:

export BYTEPLUS_API_KEY="ark-…"   # or ARK_API_KEY, the name BytePlus uses

Raising the output cap if Pi reports Response was truncated before completion.:

export BYTEPLUS_DEFAULT_MAX_TOKENS=65536

Per-model caps go in ~/.pi/agent/byteplus-model-overrides.json:

{
  "deepseek-v4-pro": { "maxTokens": 200000 },
  "Seed 2.0 Lite":   { "contextWindow": 262144 }
}

If BytePlus restructures its docs page, point the discovery at a mirror rather than waiting for a release:

export BYTEPLUS_PLAN_DOC_URL="https://mirror.example.com/coding-plan"
export BYTEPLUS_NO_ENRICHMENT=1   # or skip the scrape entirely

Every environment variable, the discovery layers, the curated limits and their provenance, and the troubleshooting messages are documented in src/README.md.

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Notes and limitations

• Built and tested against Pi 0.85.x. @earendil-works/pi-coding-agent and @earendil-works/pi-ai are optional peer dependencies: Pi provides both at runtime, and the extension installs no runtime dependencies of its own.
• I only have a Coding Plan subscription, so that is the only tier this has been exercised against. A pay-as-you-go-only key will be rejected by the Coding Plan endpoint — that is BytePlus' behaviour, not the extension's.
• BytePlus does not document a model-listing endpoint for the Coding Plan. The live /models call is therefore treated as best-effort: it is used for metadata and as a fallback, never as the authority on what the plan serves.
• Only the OpenAI-compatible wire is registered. The plan also exposes an Anthropic-protocol endpoint, but it serves the same models, so registering it would just duplicate every entry in the picker.
• The model list is parsed out of a public BytePlus documentation page, and the Coding Plan endpoint is undocumented. Either can change without notice; npm run smoke is what reports drift.

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Development

git clone https://github.com/jstokke/pi-byteplus-modelark-provider.git
cd pi-byteplus-modelark-provider
npm install
npm test          # 113 unit tests, fully mocked, ~0.6s
npm run typecheck
npm run smoke     # parses the live BytePlus docs page

To iterate without reinstalling, symlink the source into Pi's extension directory:

mkdir -p ~/.pi/agent/extensions
ln -s "$(pwd)/src" ~/.pi/agent/extensions/byteplus

See CONTRIBUTING.md for the project layout and the conventions this repo cares about.

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Disclaimer

Not affiliated with, endorsed by, or sponsored by BytePlus, ByteDance or Zhipu AI. "BytePlus", "ModelArk", "Seed", "GLM", "Kimi", "DeepSeek" and "GPT-OSS" are trademarks of their respective owners, used here only to describe what this extension interoperates with.

The extension targets an undocumented Coding Plan endpoint and parses a public BytePlus documentation page to discover models. Check that this fits BytePlus' terms for your own use.

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License

MIT © Joachim Stokke