pi-sarvam-provider

A pi coding-agent extension that registers Sarvam AI as a model provider and transparently applies the compatibility shims its OpenAI-compatible endpoint needs.

Sarvam's /v1/chat/completions endpoint is OpenAI-shaped but has a few quirks that make it fail out of the box with a general agent harness — a rejected developer role, string-only message content, a 256 KB gateway request limit, and small models that emit Claude-style tool arguments. This extension handles all of them so Sarvam models "just work" in pi.

Features

• Provider registration — discovers Sarvam models from /v1/models and registers them (reasoning enabled, thinking-level mapping, text input).
• developer → system role — Sarvam rejects the developer role pi sends for the system prompt of reasoning models. Fixed via compat.supportsDeveloperRole: false, with a payload-level safety net.
• Array content → string — Sarvam requires message.content to be a plain string; pi sends content as an array of parts. The extension flattens text parts to a string.
• Tool-argument remapping — smaller Sarvam models emit Claude-style tool arguments (file_path, old_string/new_string). These are remapped to pi's schema (path, edits[{oldText,newText}]) before schema validation via prepareArguments, composed with pi's own edit-argument recovery (so JSON-string edits still work).
• Windows path sanitisation — strips a spurious leading separator before a drive letter (/E:/work → E:\work) to avoid path.resolve doubling the drive (E:\E:\work…) and failing mkdir.
• Transient 403 retry — Sarvam's Azure gateway occasionally returns a 403 for chat completions. The extension wraps the provider stream and retries with backoff (1 s / 3 s / 8 s) when the first event is a transient error (safe, because a 403 fails at connect time before any content streams). Non-Sarvam traffic passes through untouched.
• 256 KB request-size guard — Sarvam's gateway rejects request bodies ≥ 256 KB with a 403. Long sessions cross this and then fail every turn. The extension keeps the outgoing body under the limit by stubbing the content of the oldest messages (system prompt and the most recent turns are preserved; tool-call structure stays intact). This is non-destructive — only the outgoing request is trimmed; your session history is intact.
• Editing guidance — appends concrete file-editing rules to the system prompt to help the smaller models land exact-match edits.

All behaviour is scoped to the sarvam provider; other providers are unaffected.

Requirements

• pi (the @earendil-works/pi-coding-agent CLI), v0.80 or newer.
• A Sarvam API key in the SARVAM_API_KEY environment variable.
• Node 18+ (for global fetch).

Install

pi install npm:pi-sarvam-provider

Then set your key and select a model:

export SARVAM_API_KEY="sk-..."        # PowerShell: $env:SARVAM_API_KEY = "sk-..."
pi
# /model -> pick a sarvam-* model

Add the export line to your shell config (~/.zshrc, ~/.bashrc) to keep the key across sessions.

Other useful commands:

pi list                              # show installed packages
pi install npm:pi-sarvam-provider@0.1.2   # pin a version
pi update npm:pi-sarvam-provider     # update to the latest release
pi remove npm:pi-sarvam-provider     # uninstall
pi install -l npm:pi-sarvam-provider # install into this project only (.pi/npm/)

Alternatively, list the package in the packages array of your pi settings.json (~/.pi/agent/settings.json) and pi will install it on next start:

{
  "packages": [
    "npm:pi-sarvam-provider"
  ]
}

If you previously had a local sarvam.ts in ~/.pi/agent/extensions/, delete it after installing this package to avoid registering the provider twice.

Configuration

Variable	Required	Description
SARVAM_API_KEY	yes	Your Sarvam API key. The provider is not registered if this is unset.
SARVAM_DEBUG	no	Set to true for per-request debug logging and a metrics summary on exit.
SARVAM_PROVIDER_RETRIES	no	Provider-level retries for Sarvam traffic (default 2). These are what honour a Retry-After header on 429. Set to 0 to disable.

The base URL is https://api.sarvam.ai/v1.

Notes & limitations

• The 256 KB guard is crude compaction: on oversized turns the model loses old tool outputs (it sees a stub) but keeps recent context and can re-read files. pi's own /compact can't help here because summarisation would itself exceed the 256 KB limit.
• The transient-403 retry handles brief gateway blips (seconds), not sustained multi-minute blocks. For a sustained outage, wait or switch models.

Development

pnpm install
pnpm run typecheck

To try a local change without installing the package, load the source directly — -ne disables other extensions so nothing else interferes:

pi -ne -e ./src/index.ts --provider sarvam --model sarvam-105b

Note that an installed copy of this package registers the same read/write/edit tool names as a local one, and pi rejects the duplicate rather than choosing between them. Remove the installed copy (pi remove npm:pi-sarvam-provider) before testing locally.

License

MIT