Add Perplexity as a first-class API provider

[jliounis]

Summary

Adds Perplexity (Sonar Agent API) as a first-class provider in Kilo Code, alongside existing OpenAI-compatible providers like xAI, Cerebras, and Fireworks.

The provider entry already lives in the upstream models.dev snapshot (4 chat models — sonar, sonar-pro, sonar-reasoning-pro, sonar-deep-research; default chat model is sonar-pro; 128k context for the Sonar tier and 200k for sonar-pro). This PR adds the Kilo-side customizations needed to ship it as a first-class integration:

1. Custom loader in kiloCustomLoaders that:
   • Resolves the API key from config → Auth → PERPLEXITY_API_KEY → PPLX_API_KEY fallback chain
   • Auto-loads the provider whenever a key is present
2. Attribution header wired centrally in patchCustomLoaderResult — every outgoing request carries X-Pplx-Integration: kilo-code/<package-version>. Single point, never sprinkled across call sites.
3. Unit tests covering: header constants, the patchCustomLoaderResult branch, env-var loading from both PERPLEXITY_API_KEY and the PPLX_API_KEY fallback, and the presence of the attribution header on the merged options.

OpenAI-compatible base URL: https://api.perplexity.ai. Auth: Authorization: Bearer <PERPLEXITY_API_KEY>. Branding follows the Perplexity guidelines — never "Sonar API".

Pattern reference

This mirrors the Perplexity provider PR for Cline, adapted to Kilo Code's opencode-fork architecture (custom loaders + patchCustomLoaderResult rather than a per-provider Handler class). The header injection follows the existing cerebras X-Cerebras-3rd-Party-Integration precedent in the same file.

Co-authored by mirroring sibling provider conventions in this repo.

Docs

• API reference: https://docs.perplexity.ai/api-reference/agent-post
• Models: https://docs.perplexity.ai/models/model-cards
• 4 models · 128k–200k context · default sonar-pro

Test plan

• bun test packages/opencode/test/kilocode/perplexity-provider.test.ts (added in this PR)
• Set PERPLEXITY_API_KEY and verify kilo lists perplexity provider with sonar-pro model
• Drop PERPLEXITY_API_KEY, set PPLX_API_KEY, confirm fallback path also auto-loads
• Inspect outgoing request headers — confirm X-Pplx-Integration: kilo-code/<version> is present

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (2 files)

• packages/opencode/src/kilocode/provider/provider.ts
• packages/opencode/test/kilocode/perplexity-provider.test.ts

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_{Reviewed by gpt-5.5-2026-04-23 · 1,159,496 tokens}