🪸 pi-coralbricks-provider

GLM 5.3, GLM 5.3 Flash, Kimi K3 & GPT-OSS 120B through Coral Bricks

A pi provider extension for Coral's OpenAI-compatible inference gateway — up to 1M context on open models.

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Features

• 4 reasoning models from Coral's live catalog — GLM 5.3 FP4, GLM 5.3 Flash, Kimi K3, and GPT-OSS 120B
• 1M token context on GLM and Kimi, with vision (image input) on Kimi K3 and GLM 5.3 Flash
• OpenAI-compatible API — standard /v1/chat/completions, streaming, and tool calling
• Per-family thinking levels — zai-style thinking control for GLM (including a real off switch), reasoning_effort for Kimi K3 and GPT-OSS
• Accurate cost tracking — pricing mirrors Coral's published rates, and cached reads are $0 on every model, so pi's computed cost matches Coral's own usage.cost to the token
• Self-healing model sync — stale-while-revalidate from the authenticated /v1/models (or the unauthenticated public catalog before auth), hot-swapped at session start
• synbad-validated — synbad tool-calling and reasoning-parsing evals pass 13/13 in every run on GLM 5.3 and Kimi K3 in both unary and streaming modes

Installation

Option 1: Using pi install (Recommended)

Install directly from GitHub:

pi install https://github.com/monotykamary/pi-coralbricks-provider

or from npm:

pi install npm:pi-coralbricks-provider

Then set your API key and run pi:

# Recommended: add to auth.json
# See Authentication section below

# Or set as environment variable
export CORALBRICKS_API_KEY=cb_your-key-here

pi

Option 2: Manual Clone

1. Clone this repository:

   git clone https://github.com/monotykamary/pi-coralbricks-provider.git
   cd pi-coralbricks-provider
   bun install
   

2. Set your Coral API key:

   # Recommended: add to auth.json
   # See Authentication section below
   
   # Or set as environment variable
   export CORALBRICKS_API_KEY=cb_your-key-here
   

3. Run pi with the extension:

   pi -e /path/to/pi-coralbricks-provider
   

Available Models

Model	Context	Vision	Reasoning	Input $/M	Cache Read $/M	Output $/M
GLM 5.3 Flash	1.0M	✅	✅	$0.15	—	$0.50
GLM 5.3 FP4	1.0M	❌	✅	$1.12	—	$4.40
GPT-OSS 120B	131K	❌	✅	$0.12	—	$0.60
Kimi K3	1.0M	✅	✅	$3.00	—	$15.00

Costs are per million tokens. Cache Read shows — because Coral bills cached input at $0 on every model. Prices subject to change — check Coral's live catalog.

Usage

After loading the extension, use the /model command in pi to select your preferred model:

/model coralbricks glm-5.3-fp4

Or start pi directly with a Coral model:

pi -e /path/to/pi-coralbricks-provider --model coralbricks/kimi-k3:high

Thinking levels attach to the model id with :<level> — e.g. :low, :high, :max, or :off (GLM only).

Authentication

The Coral API key can be configured in multiple ways (resolved in this order):

1. auth.json (recommended) — Add to ~/.pi/agent/auth.json:

   { "coralbricks": { "type": "api_key", "key": "cb_your-key" } }
   

   The key field supports literal values, env var names, and shell commands (prefix with !).
2. Runtime override — Use the --api-key CLI flag
3. Environment variable — Set CORALBRICKS_API_KEY

With localterm, store it once and it's exposed everywhere:

localterm secret set coralbricks_api_key

Coral Inference is currently in a design-partner program — mint keys at coralbricks.ai/api-keys. Newly-minted keys may take ~30 seconds to be honored, and 403 access_denied means the account isn't on the allowlist yet.

Thinking Levels

Verified against the live gateway:

Model	Format	off	low	medium	high	max
GLM 5.3 FP4	thinking: {type} + reasoning_effort	✅	✅	—	✅	✅
GLM 5.3 Flash	thinking: {type} + reasoning_effort	✅	✅	—	✅	✅
Kimi K3	reasoning_effort	—	✅	—	✅	✅
GPT-OSS 120B	reasoning_effort	—	✅	✅	✅	—

• GLM accepts zai-style thinking: {type: "disabled"} on Coral — pi's off level turns thinking off, though a short preamble of a few dozen tokens can still appear (the upstream Z.ai API has no off at all, so this differs from the canonical Z.ai map).
• Kimi K3 always thinks: reasoning_effort: "none" is accepted but doesn't disable reasoning, so off is intentionally not offered. Assistant replays include reasoning_content.
• GPT-OSS exposes the standard low/medium/high reasoning efforts; reasoning arrives in reasoning_content.
• Coral streams a duplicate reasoning field alongside reasoning_content; pi dedupes these automatically.

Compat Settings

Coral's gateway follows the OpenAI Chat Completions API:

• supportsStore: false / supportsDeveloperRole: false — all models; Coral serves open models on the classic roles.
• maxTokensField: "max_tokens" — all models.
• thinkingFormat: "zai" — GLM 5.3: thinking: {type: "enabled"|"disabled"} toggles reasoning, reasoning_effort picks the depth.
• thinkingFormat: "openai" — Kimi K3 and GPT-OSS 120B: reasoning_effort drives thinking depth.
• supportsStrictMode: false — Kimi K3 (no strict JSON-schema tool definitions).
• requiresReasoningContentOnAssistantMessages: true — Kimi K3.

Patch Overrides & Custom Models

• patch.json — per-model overrides applied on top of models.json (reasoning flags, pricing corrections, compat settings, thinking level maps). Currently carries the GLM 5.3 Flash entry: reasoning, image input, its thinking level map and compat settings.
• custom-models.json — full model definitions for models Coral doesn't list. Merged after patch.

Merge order: [live|cache|embedded] → patch.json → custom-models.json

Inference-Quality Testing

Validated with synbad — Synthetic's tool-calling and reasoning-parsing eval suite for LLM inference providers (current 13-eval suite, --reasoning-effort high, five --count 1 runs per mode on 2026-09-15; a cell shows the evals that passed in every run):

Model	Unary	Stream	Notes
GLM 5.3 FP4	13/13 ✅	13/13 ✅	5/5 runs
GLM 5.3 Flash	12/13 ⚠️	12/13 ⚠️	reasoning/reasoning-parsing passes 4 of 5 runs; see below
Kimi K3	13/13 ✅	13/13 ✅	5/5 runs
GPT-OSS 120B	12/13 ⚠️	12/13 ⚠️	tools/parallel-tool 0 of 5 runs; see below
GLM 5.2 FP4 (retired)	15/15 ✅	15/15 ✅	15-eval suite, single run, before Coral retired the model

The two misses are model-side, not transport: gpt-oss answers "Paris and London" with one call after another instead of two parallel calls even when parallel_tool_calls: true, in every run; and on the trivial prompt reasoning-parsing uses, GLM 5.3 Flash answers without a think block about one run in five, in both modes, with the answer itself unaffected.

Reproduce:

CORALBRICKS_API_KEY=cb_... node ../synbad/dist/source/index.js eval \
  --env-var CORALBRICKS_API_KEY \
  --base-url https://inference.coralbricks.ai/v1 \
  --model glm-5.3-fp4 --count 1 --reasoning-effort high

Updating Models

Run the update script to fetch the latest models from Coral's API:

export CORALBRICKS_API_KEY=cb_your-key
node scripts/update-models.js

This will:

1. Fetch models from https://inference.coralbricks.ai/v1/models (falls back to the unauthenticated public catalog without a key)
2. Preserve existing model data (pricing, compat, thinking maps) for known models
3. Apply overrides from patch.json
4. Update models.json and the README model table

To regenerate just the README model table from local data — no API key needed:

node scripts/update-models.js --readme-only

Troubleshooting

Symptom	Meaning
403 access_denied	Account not on the Coral Inference allowlist yet
404 model_not_accepted	Model id not enabled for your key
401 invalid_api_key	Re-mint at coralbricks.ai/api-keys; fresh keys take ~30s to activate
429 rate_limit_exceeded	Per-key rate limit — retry with backoff
502 upstream_error / 503 backend_unconfigured	Transient — retry
504 timeout	Sync request waited too long; re-issue smaller or use Coral's background Responses API

License

MIT