fix(answer): update to getApiKeyAndHeaders API (pi-coding-agent 0.63+)

[affsantos]

Problem

answer.ts extension crashes with:

Extension "command:answer" error: modelRegistry.getApiKey is not a function

Cause

ModelRegistry.getApiKey() was renamed to getApiKeyAndHeaders() in pi-coding-agent v0.63.0 (pi-mono@7a786d88, Mar 27 2026). The new method returns a ResolvedRequestAuth object instead of a plain string, supporting both API keys and request headers.

The pi-mono examples (qna.ts) were updated in the same commit, but this extension was not — since it lives in a separate repo.

Investigation trail

1. The error modelRegistry.getApiKey is not a function pointed to the ModelRegistry API
2. Checked pi-mono's model-registry.ts git history and found commit 7a786d88 (fix(coding-agent): resolve models.json auth per request closes #1835) which:
   • Renamed getApiKey(model) → getApiKeyAndHeaders(model)
   • Changed the return type from Promise<string | undefined> to Promise<ResolvedRequestAuth> ({ ok: true, apiKey?, headers? } | { ok: false, error })
   • Updated all pi-mono examples including qna.ts (which this extension was originally based on)
3. Confirmed: pi-mono checkout is at v0.62.0 (still has getApiKey), installed pi is v0.63.1 (has getApiKeyAndHeaders only)

Changes

• Replace inline modelRegistry type with the actual ModelRegistry import from @mariozechner/pi-coding-agent
• Use getApiKeyAndHeaders() which returns { ok, apiKey?, headers? } | { ok: false, error }
• Pass headers alongside apiKey to complete() for proper auth (needed for providers with custom headers)
• Add error handling when auth resolution fails

Notes

This is honestly my favourite pi extension — the interactive Q&A TUI for answering questions inline is brilliant. Just wanted to get it working again on 0.63+ 🙏

[marvelm]

I'm running this patch on pi@0.63.2 - and it works correctly.

$ git -P diff HEAD

diff --git a/settings.json b/settings.json
index b160283..2aef010 100644
--- a/settings.json
+++ b/settings.json
@@ -1,5 +1,5 @@
 {
-  "lastChangelogVersion": "0.62.0",
+  "lastChangelogVersion": "0.63.2",
   "defaultProvider": "anthropic",
   "defaultModel": "claude-opus-4-6",
   "defaultThinkingLevel": "medium",
@@ -8,7 +8,7 @@
   ],
   "packages": [
     {
-      "source": "npm:mitsupi",
+      "source": "git:github.com/affsantos/agent-stuff@fix/answer-getApiKey-rename",
       "extensions": [
         "pi-extensions/answer.ts"
       ],

[marvelm]

Thank you @mitsuhiko for making this extension. It's what convinced me to switch to Pi