fix: harden request validation and profileArn handling for Kiro API

[ranjanjyoti152]

Summary

Hardens request validation and profileArn handling so several requests that
previously failed with opaque upstream errors now work, and any remaining
misconfiguration produces an actionable message instead of Kiro's cryptic
REQUEST_BODY_INVALID.

All changes follow the project philosophy: shared core fixes applied to both
the OpenAI and Anthropic surfaces and both streaming and non-streaming
paths, with paranoid test coverage.

What it fixes

These all surfaced as HTTP 400 Improperly formed request (REQUEST_BODY_INVALID)
or hard 422s when proxying Claude Code traffic:

1. Inline system role in the Anthropic messages array — some clients
   (Claude Code) inline {"role": "system", ...} instead of using the
   top-level system field. This was rejected with a Pydantic 422. Now the
   role is accepted and folded into the system prompt (order preserved,
   combined with any top-level system, excluded from history).

2. $schema (and other JSON Schema meta keywords) in tool input_schema —
   Claude Code sends "$schema" on every tool. Kiro/Bedrock rejects it. The
   sanitizer now strips $schema, $id, $anchor, $comment recursively
   (preserving structural $ref/$defs).

3. Tool schema root type — Bedrock requires every tool
   inputSchema.json.type to be "object" (error:
   toolConfig.tools.N.toolSpec.inputSchema.json.type must be one of [object]).
   No-argument / malformed tool schemas are now normalized to a valid object
   schema with a properties map.

4. profileArn handling — a shared Profile_Resolver
   (auth manager → PROFILE_ARN → empty) with:

   • early, actionable error when no profileArn can be resolved (instead of an
     opaque upstream 400), and
   • format validation that rejects the ... documentation placeholder with a
     clear message telling the user to set a real ARN.

New

• kiro/profile_resolver.py — shared resolution + ARN validation
• Exceptions: MissingProfileArnError, MalformedProfileArnError

Tests

Comprehensive unit + integration coverage across both APIs and both streaming
modes: schema sanitization, object-type normalization, inline-system folding
and ordering, resolver rules, ARN validation, and route-level error responses.
Full suite passes locally.

Note for maintainers

The README states AWS SSO / Builder ID users don't need a profileArn. The
missing/malformed profileArn guards here were validated against an
Enterprise / IAM Identity Center account where the Kiro runtime does
require it. Happy to gate the strictness (e.g. only error for auth types that
require a profileArn) if you'd prefer — let me know.

[cla-bot]

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[ranjanjyoti152]

I have read the CLA and I accept its terms

…

On Mon, 15 Jun 2026 at 4:56 PM, cla-bot[bot] ***@***.***> wrote: *cla-bot[bot]* left a comment (jwadow/kiro-gateway#222) <#222 (comment)> Thanks for the PR! 🎉 Before merge, we need a one-time CLA confirmation. It confirms that you have the right to contribute this code and allow the project to use it. Full CLA text: https://github.com/jwadow/kiro-gateway/blob/main/CLA.md Please reply once with: I have read the CLA and I accept its terms You need to write once, all further messages from me can be ignored. — Reply to this email directly, view it on GitHub <#222?email_source=notifications&email_token=AFQQEP66FNOWU6UJJTNQIID477MOXA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTINZQG42DGNBWHA42M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L#issuecomment-4707434689>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFQQEP7ICI6P7FKNK6K4HWD477MOXAVCNFSNUABGKJSXA33TNF2G64TZHMYTCMJVGQ4DSMRRHA5US43TOVSTWNBWGY2DMMRSGIZTRILWAI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[ranjanjyoti152]

I have read the CLA and I accept its terms

[cla-bot]

Thanks for the PR! 🎉

Before merge, we need a one-time CLA confirmation.
It confirms that you have the right to contribute this code and allow the project to use it.

Full CLA text:
https://github.com/jwadow/kiro-gateway/blob/main/CLA.md

Please reply once with:

I have read the CLA and I accept its terms

You need to write once, all further messages from me can be ignored.

[ranjanjyoti152]

I have read the CLA and I accept its terms

[ranjanjyoti152]

@jwadow I've posted the CLA acceptance ("I have read the CLA and I accept its terms") but the cla-bot isn't re-checking. Could you re-run the CLA check or add me to the contributors list? Thanks! 🙏