refactor(api-proxy): extract ProviderAdapter abstraction, make core provider-agnostic

[Copilot]

server.js (2,164 lines) had 5 near-identical per-provider server creation blocks with all auth, URL transform, body transform, and validation logic inlined. Adding a provider required touching 7+ locations; there was no isolation for testing provider logic independently.

Architecture

proxy-utils.js — shared pure utilities

normalizeApiTarget, normalizeBasePath, buildUpstreamPath, stripGeminiKeyParam, shouldStripHeader, composeBodyTransforms. No provider knowledge.

providers/<name>.js — one file per provider

Each adapter implements a consistent interface; the core calls only interface methods:

// providers/gemini.js (example)
return {
  name: 'gemini', port: 10003,
  alwaysBind: true,                          // 503 stub when unconfigured
  get participatesInValidation() { return this.isEnabled(); },
  isEnabled()          { return !!apiKey; },
  getTargetHost()      { return rawTarget; },
  getBasePath()        { return basePath; },
  getAuthHeaders()     { return { 'x-goog-api-key': apiKey }; },
  transformRequestUrl(url) { return stripGeminiKeyParam(url); },
  getBodyTransform()   { return bodyTransform; },
  getValidationProbe() { ... },
  getModelsFetchConfig() { ... },
  getReflectionInfo()  { ... },
};

File	Encapsulates
providers/openai.js	Port 10000, management port, /v1 base-path default for public endpoint
providers/anthropic.js	Auto-cache, ANSI stripping, tool-drop, dual beta-header injection
providers/copilot.js	Dual-auth (GitHub token vs BYOK), /models GET special-casing, GHEC/GHES target derivation
providers/gemini.js	Always-bind 503 fallback, ?key= param stripping
providers/opencode.js	Transparent routing layer — delegates all per-request decisions to candidateAdapters
providers/index.js	createAllAdapters() + ProviderAdapter typedef

server.js — generic engine, zero provider knowledge

createProviderServer(adapter) replaces 5 duplicated per-provider server blocks. validateApiKeys, fetchStartupModels, reflectEndpoints, healthResponse, and buildModelsJson all iterate over registeredAdapters with no provider names hardcoded.

// Entire startup block is now:
for (const adapter of adaptersToStart) {
  const server = createProviderServer(adapter);
  server.listen(adapter.port, '0.0.0.0', () => {
    if (adapter.participatesInValidation) onListenerReady();
  });
}

Multiple providers active simultaneously

Every provider binds its own port and is independently reachable regardless of what else is configured. OpenCode (port 10004) is a routing layer on top: it accepts a candidateAdapters array and delegates all per-request decisions — target host, base path, auth headers, body transforms, URL transforms — to the first enabled adapter in that list.

// providers/index.js — the only place routing priority is defined
const opencode = createOpenCodeAdapter(env, {
  candidateAdapters: [openai, anthropic, copilot], // first enabled wins
});

Changing the priority or adding a new provider to OpenCode's routing is a single-line edit in providers/index.js — opencode.js itself never needs to change.

providers/ADDING-A-PROVIDER.md

Step-by-step guide: create adapter file → register in index.js → update Dockerfile → optionally add to OpenCode's candidateAdapters. Adding a provider no longer requires touching core server logic.

Impact

• Adding a provider now touches 2 files (new adapter + index.js) instead of 7+ locations in one monolith
• Each adapter is unit-testable in isolation without starting HTTP servers
• buildUpstreamPath is now fully provider-agnostic; the OpenAI /v1 default moved to the OpenAI adapter's getBasePath()
• All five providers can be simultaneously active; OpenCode routing priority is data-driven and extensible without modifying opencode.js

[github-actions]

✅ Coverage Check Passed

Overall Coverage

Metric	Base	PR	Delta
Lines	85.76%	85.84%	📈 +0.08%
Statements	85.64%	85.72%	📈 +0.08%
Functions	88.11%	88.11%	➡️ +0.00%
Branches	78.65%	78.69%	📈 +0.04%

📁 Per-file Coverage Changes (1 files)

File	Lines (Before → After)	Statements (Before → After)
src/docker-manager.ts	87.4% → 87.7% (+0.29%)	87.0% → 87.3% (+0.27%)

---

Coverage comparison generated by scripts/ci/compare-coverage.ts

[lpcox]

@copilot make sure that multiple providers can be active at once with extensible logic for switching between active providers

[github-actions]

Smoke Test Results

• GitHub MCP: ❌ (Tools not registered)
• GitHub Connectivity: ✅ (200)
• File Writing: ✅
• Bash Tool: ✅

Overall Status: FAIL

PR Titles:

1. fix: move smoke-gemini tests into agent container (fix: move smoke-gemini tests into agent container #2401)
2. (N/A - tool failure)

💎 Faceted by Smoke Gemini

[github-actions]

🔬 Smoke Test Results

Test	Status
GitHub MCP connectivity	✅
GitHub.com HTTP	✅ 200
File write/read	❌ (pre-step vars not expanded)

Overall: FAIL (file test inconclusive — $\{\{ steps.smoke-data.outputs }} not substituted)

PR: refactor(api-proxy): extract ProviderAdapter abstraction — author @Copilot, assignees @lpcox @Copilot

📰 BREAKING: Report filed by Smoke Copilot

[github-actions]

Smoke Test: Copilot BYOK (Offline Mode)

Test	Result
GitHub MCP connectivity	✅
GitHub.com HTTP	⚠️ pre-step data unavailable (template not expanded)
File write/read	⚠️ pre-step data unavailable (template not expanded)
BYOK inference (agent → api-proxy → api.githubcopilot.com)	✅

Running in BYOK offline mode (COPILOT_OFFLINE=true) via api-proxy → api.githubcopilot.com.

PR author: @Copilot | Assignees: @lpcox, @Copilot

Overall: PARTIAL (BYOK inference path confirmed working; pre-step smoke data was not injected)

🔑 BYOK report filed by Smoke Copilot BYOK

[github-actions]

Smoke Test Results

✅ GitHub MCP: Listed last 2 merged PRs
✅ Playwright: https://github.com title verified
✅ File Writing: Test file created with timestamp
✅ Bash Tool: File content verified

Status: PASS

💥 [THE END] — Illustrated by Smoke Claude

[github-actions]

Chroot Version Comparison Results

Runtime	Host Version	Chroot Version	Match?
Python	Python 3.12.13	Python 3.12.3	❌ NO
Node.js	v24.14.1	v20.20.2	❌ NO
Go	go1.22.12	go1.22.12	✅ YES

Overall: FAILED — Python and Node.js versions differ between host and chroot environments.

Tested by Smoke Chroot

[github-actions]

fix: move smoke-gemini tests into agent container
feat: unify schema versioning — use repo release tag for all schemas, publish JSONL schemas as release assets
GitHub MCP: ❌
safeinputs-gh: ❌
Playwright: ✅
Tavily: ❌
File/bash: ✅
Discussion comment: ✅
Build: ✅
Overall: FAIL

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

• registry.npmjs.org

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "registry.npmjs.org"

See Network Configuration for more information.

🔮 The oracle has spoken through Smoke Codex

[github-actions]

🏗️ Build Test Suite Results

Ecosystem	Project	Build/Install	Tests	Status
Bun	elysia	✅	1/1 passed	✅ PASS
Bun	hono	✅	1/1 passed	✅ PASS
C++	fmt	✅	N/A	✅ PASS
C++	json	✅	N/A	✅ PASS
Deno	oak	N/A	1/1 passed	✅ PASS
Deno	std	N/A	1/1 passed	✅ PASS
.NET	hello-world	✅	N/A	✅ PASS
.NET	json-parse	✅	N/A	✅ PASS
Go	color	✅	1/1 passed	✅ PASS
Go	env	✅	1/1 passed	✅ PASS
Go	uuid	✅	1/1 passed	✅ PASS
Java	gson	✅	1/1 passed	✅ PASS
Java	caffeine	✅	1/1 passed	✅ PASS
Node.js	clsx	✅	passed	✅ PASS
Node.js	execa	✅	passed	✅ PASS
Node.js	p-limit	✅	passed	✅ PASS
Rust	fd	✅	1/1 passed	✅ PASS
Rust	zoxide	✅	1/1 passed	✅ PASS

Overall: 8/8 ecosystems passed — ✅ PASS

Generated by Build Test Suite for issue #2409 · ● 555.9K · ◷

[github-actions]

Smoke Test Results

• Redis PING: ❌ (timeout — no response)
• PostgreSQL pg_isready: ❌ (no response)
• PostgreSQL SELECT 1: ❌ (skipped — host unreachable)

Overall: FAIL — host.docker.internal is not reachable from this runner environment. Service containers may not be running or the hostname is not resolvable.

🔌 Service connectivity validated by Smoke Services