open-fusion-config-json

name	open-fusion-config-json
description	Implement and maintain Open Fusion's single JSON configuration system. Use when Codex works on config schema, loading, validation, environment variable secret resolution, provider/model/route/auth configuration, default config examples, config tests, or migrations for the Open Fusion LLM gateway.

Open Fusion Config JSON

Required Context

Before editing configuration code or examples, read:

• docs/PRD.md
• docs/specs/003-single-json-configuration.md
• docs/adrs/0004-single-json-configuration.md

Read provider and orchestration specs when config fields affect those areas:

• docs/specs/002-llm-orchestration-routing.md
• docs/specs/004-provider-adapters-openrouter.md
• docs/specs/007-observability-resilience-security.md

Configuration Contract

The MVP uses one JSON file loaded at boot. The config path comes from OPEN_FUSION_CONFIG, with ./config/open-fusion.config.json as the fallback candidate.

The application must fail before listening for HTTP if required config is invalid.

Schema Responsibilities

Validate at least:

• supported version;
• known provider type;
• model references to existing providers;
• route references to existing orchestrator models;
• delegate model references to existing models with delegate role;
• maxDepth equal to 1 for MVP;
• positive timeout and delegation limits;
• payload, message-count, and message-content limits when those limits are configured;
• auth key entries with resolvable secret references.

Prefer a typed schema validator that produces field paths in errors.

Secrets

• Treat *Env fields as references to environment variables.
• Resolve secrets at boot or through a secret resolver service.
• Never log resolved secret values.
• Never return resolved secret values from debug, health, models, or error responses.
• Redact apiKey, token, authorization, and configured redaction keys.

Design Rules

• Keep raw parsed JSON separate from validated runtime config.
• Expose immutable typed config objects to the rest of the app.
• Avoid reading process.env outside config/bootstrap/secret resolution code.
• Do not scatter provider-specific config parsing through orchestration or controllers.
• Add migrations only after introducing a new config version.

Testing

Cover valid minimal config, missing env secret, unknown provider, invalid route reference, invalid delegate model, and redaction behavior.