release(v0.39.1): SEP-2787 reference impl follows spec into camelCase

[vaaraio]

Summary

• SEP-2787 reference implementation follows the spec into MCP camelCase. soup-oss adopted camelCase across the envelope in modelcontextprotocol/modelcontextprotocol@48c739b1; this patch updates vaara.attestation.sep2787 to emit matching JSON keys.
• Python dataclass attributes stay snake_case (Pythonic). The rename is at the serialisation boundary only, so user code is unchanged.
• New issuer_to_dict helper replaces dataclasses.asdict() so the issuer block sorts and renames deterministically.
• docs/sep2787-overt-mapping.md field-by-field table updated.

Field renames at the JSON boundary

Snake (was)	Camel (now)
planner_declared	plannerDeclared
issuer_asserted	issuerAsserted
payload_derived	payloadDerived
tool_calls	toolCalls
server_fingerprint	serverFingerprint
secret_version	secretVersion
exp_seconds	expSeconds
requested_capability	requestedCapability
projection_digest	projectionDigest

Provenance tags

• sep2787-ref-v0 (commit 3d7af54): snake_case envelope, historical proposed-shape artefact. Preserved unchanged.
• sep2787-ref-v1 (new, this release): camelCase envelope. Pinned for cross-repo citation against modelcontextprotocol/modelcontextprotocol#2787 and the v0 test vector PR (vaaraio/modelcontextprotocol#2789, head 2a9360f).

Test plan

• pytest tests/test_attestation_sep2787.py — 28/28 pass
• ruff check src/vaara/attestation/ tests/test_attestation_sep2787.py — clean
• pyproject.toml 0.39.0 → 0.39.1
• src/vaara/__init__.py 0.39.0 → 0.39.1
• clients/ts/package.json 0.39.0 → 0.39.1
• CHANGELOG entry under ## [0.39.1] - 2026-05-27

Summary by CodeRabbit

Version 0.39.1

• Updates
  • JSON serialization output format updated to use camelCase field names (e.g., plannerDeclared, issuerAsserted, payloadDerived, toolCalls, serverFingerprint) instead of previous snake_case convention.
  • Reference implementation documentation updated with new field naming conventions.
  • Test coverage updated to validate camelCase output format.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 8b117d58-b1f1-43a3-9664-9883a08d49e1

📥 Commits

Reviewing files that changed from the base of the PR and between a144455 and 4c9679c.

📒 Files selected for processing (10)

• CHANGELOG.md
• clients/ts/package.json
• docs/sep2787-overt-mapping.md
• pyproject.toml
• src/vaara/__init__.py
• src/vaara/attestation/_sep2787_emit.py
• src/vaara/attestation/_sep2787_types.py
• src/vaara/attestation/_sep2787_verifier.py
• src/vaara/attestation/sep2787.py
• tests/test_attestation_sep2787.py

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📝 Walkthrough

Walkthrough

This PR converts the SEP-2787 attestation envelope JSON serialization from snake_case to camelCase field names. The core schema serialization functions are updated, the signing and verification logic is integrated with the new schema, documentation is synchronized, tests are updated to validate the change, and version numbers are bumped to 0.39.1.

Changes

SEP-2787 camelCase Envelope Schema and Integration

Layer / File(s)	Summary
Attestation serialization to camelCase src/vaara/attestation/_sep2787_types.py	Attestation.to_dict(), planner_to_dict(), issuer_to_dict(), and args_to_dict() are updated to emit camelCase JSON keys (plannerDeclared, issuerAsserted, payloadDerived, toolCalls, serverFingerprint, requestedCapability, expSeconds, secretVersion, projectionDigest). The issuer_to_dict() helper replaces direct asdict() calls for deterministic issuer block conversion.
Signing payload and verification integration src/vaara/attestation/_sep2787_emit.py, src/vaara/attestation/_sep2787_verifier.py	_signing_payload() constructs the JCS canonical envelope body using camelCase field names and calls issuer_to_dict() for issuer conversion. Validation error messages now reference camelCase field paths (plannerDeclared.intent, plannerDeclared.toolCalls). Verifier documentation is updated to use camelCase argument commitment field names (argsRef, argsProjection).
Documentation and mapping updates docs/sep2787-overt-mapping.md, src/vaara/attestation/sep2787.py	Module-level documentation switches to camelCase envelope field naming. The OVERT 1.0 ↔ SEP-2787 mapping table is updated with camelCase JSON key paths and field identifiers.
Test updates for camelCase assertions tests/test_attestation_sep2787.py	test_to_dict_round_trip_shape is updated to assert camelCase keys in Attestation.to_dict() output and validates nested field structures with updated key paths.
Version number updates CHANGELOG.md, clients/ts/package.json, pyproject.toml, src/vaara/__init__.py	Project version bumped from 0.39.0 to 0.39.1. Release notes document the SEP-2787 camelCase JSON serialization changes, the new issuer_to_dict helper, and reference tags for camelCase and snake_case envelope versions.

🎯 2 (Simple) | ⏱️ ~10 minutes

A rabbit hops through the schema with glee,
camelCase keys flow naturally,
issuer blocks converted with care,
documents updated everywhere,
version bumped, the spec now fair! 🐰✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: converting SEP-2787 reference implementation output to camelCase JSON keys to match the specification.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch release/v0.39.1

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