Add Claude Code provider plugin

[chubes4]

Summary

• Add a wp-coding-agents-carried ai-provider-for-claude-code WP AI Client provider backed by Claude Code OAuth credentials and Anthropic Messages API requests.
• Sync and activate the carried provider during setup/upgrade when Claude Code is the selected or detected runtime.
• Document the Homeboy Codebox path and add regression coverage for OAuth/API provider routing and read-only Codebox canary construction.

Testing

• bash -n setup.sh upgrade.sh lib/carried-plugins.sh lib/homeboy.sh lib/agents-md-guidance.sh
• php -l on all carried-plugins/ai-provider-for-claude-code PHP files
• bash tests/carried-claude-code-plugin.sh && bash tests/homeboy-codebox-canary.sh && bash tests/agents-md-guidance.sh
• git diff --check
• EXISTING_WP="/Users/chubes/Studio/intelligence-chubes4" ./setup.sh --local --runtime claude-code --dry-run --no-chat
• ./upgrade.sh --local --wp-path "/Users/chubes/Studio/intelligence-chubes4" --runtime claude-code --dry-run --plugins-only
• php -r 'define("ABSPATH", __DIR__ . "/"); function add_action($hook, $callback, $priority = 10) { call_user_func($callback); } require "carried-plugins/ai-provider-for-claude-code/ai-provider-for-claude-code.php"; echo "loaded\n";'

Live canary

• claude-code-provider-oauth-canary-20260608-007
• Provider: claude-code
• Model: claude-sonnet-4-6
• Result: succeeded
• Changed files: 0
• Patch bytes: 0
• Evidence paths captured by Homeboy:
  • Status: /var/folders/lr/c_cmmt7s0592m4njz99v5yb40000gn/T/tmp.vUFYw5hhK3/status.json
  • Logs: /var/folders/lr/c_cmmt7s0592m4njz99v5yb40000gn/T/tmp.vUFYw5hhK3/logs.json
  • Artifacts: /var/folders/lr/c_cmmt7s0592m4njz99v5yb40000gn/T/tmp.vUFYw5hhK3/artifacts.json

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (openai/gpt-5.5)
• Used for: Implemented the carried Claude Code provider plugin, OAuth/API rewrite, setup/upgrade wiring, docs, regression tests, and Homeboy Codebox canary fixes; Chris directed the architecture and remains responsible for review/testing.

[chubes4]

Status: blocked on WP Codebox Claude Code runtime support

This PR is not done by the Homeboy Codebox cooking gate yet.

What is proven:

• ai-provider-for-claude-code is mounted and activated by WP Codebox.
• Homeboy deterministic agent-task orchestration runs and emits Codebox artifacts.
• The provider reaches execution inside the sandbox.

Failing canary evidence:

• Run: claude-code-provider-canary-20260608-0002
• Result: failed
• Provider plugin loaded: ai-provider-for-claude-code/ai-provider-for-claude-code.php
• Runtime policy: network: deny, commands: wordpress.wp-cli, wordpress.run-php, hostTools: []
• Failure: Claude Code exited with status 127
• Changed files: 0
• Patch bytes: 0

Additional probe:

• Run: claude-code-provider-canary-20260608-0004
• Mounted local /Users/chubes/.local/bin/claude into the runtime as /usr/local/bin/claude
• Set AI_PROVIDER_CLAUDE_CODE_BIN=/usr/local/bin/claude
• Result remained Claude Code exited with status 127

Diagnosis:

The PHP provider approach cannot power Codebox cooking until WP Codebox/Homeboy exposes a first-class Claude Code execution surface to the sandbox or runs Claude Code as the outer Codebox agent. The current Playground runtime cannot execute the host-authenticated claude CLI from PHP.

Upstream tracker: Automattic/wp-codebox#807

[chubes4]

Status update: CLI blocker removed

The provider implementation has been rewritten in commit 91d526e to remove the PHP proc_open / local claude CLI runtime entirely.

Current shape:

• ai-provider-for-claude-code now extends WP AI Client's API provider path.
• Auth is Claude Code OAuth via AI_PROVIDER_CLAUDE_CODE_REFRESH_TOKEN plus optional cached access token env/constant/filter values.
• Requests go to Anthropic Messages API with Claude Code OAuth headers, including Claude Code beta headers and identity prompt.
• The old ClaudeCodeProcess runtime file has been deleted.
• tests/carried-claude-code-plugin.sh now asserts the OAuth support files exist and the CLI process runtime is absent.

Verification after rewrite:

• php -l on all Claude provider PHP files
• bash tests/carried-claude-code-plugin.sh && bash tests/homeboy-codebox-canary.sh && bash tests/agents-md-guidance.sh
• git diff --check

Live model-backed Homeboy Codebox canary is still pending because AI_PROVIDER_CLAUDE_CODE_REFRESH_TOKEN is not set in the local shell. The earlier Claude Code exited with status 127 canary evidence applied to the deleted CLI-backed implementation and is superseded by this rewrite.

[chubes4]

Status update: Homeboy Codebox canary passing

The Claude Code OAuth provider now passes the read-only Homeboy Codebox canary.

Canary evidence:

• Run: claude-code-provider-oauth-canary-20260608-007
• Provider: claude-code
• Model: claude-sonnet-4-6
• Result: succeeded
• Changed files: 0
• Patch bytes: 0

What changed after the earlier OAuth rewrite:

• Removed the newer ProviderWithRequestAuthenticationInterface dependency so the plugin loads against the PHP AI Client version bundled in Codebox.
• Explicitly registers ClaudeCodeRequestAuthentication with the WP AI Client provider registry.
• Makes ClaudeCodeRequestAuthentication compatible with the current registry's API-key auth validation while still applying Claude Code OAuth headers.
• Serializes non-text message parts into text payload blocks so Agents API tool/function context does not crash text generation.
• Keeps Discord routing in provider config only; the canary helper no longer passes unsupported --channel / --thread flags to homeboy agent-task dispatch.

Verification:

• php -l on changed provider PHP files
• bash tests/homeboy-codebox-canary.sh && bash tests/carried-claude-code-plugin.sh && bash tests/agents-md-guidance.sh && git diff --check
• Live Homeboy Codebox canary above

[chubes4]

Status update: Opus 4.8 canary passing

Added claude-opus-4-8 to the provider model map (verified as a live Anthropic model id via /v1/models) and confirmed the read-only Homeboy Codebox canary passes on it.

Canary evidence:

• Run: claude-code-provider-oauth-canary-20260608-009
• Provider: claude-code
• Model: claude-opus-4-8
• Result: succeeded
• Changed files: 0
• Patch bytes: 0

Provider now declares models: claude-opus-4-8, claude-opus-4-7, claude-sonnet-4-6, claude-haiku-4-5.

[chubes4]

Update: structured tool calling added

The provider now implements Anthropic structured tool calling, replacing the prior text-only generation that forced the model to improvise tool calls as freeform text.

Commit fdf79db:

• Declares the agent's FunctionDeclarations as Anthropic tools with input_schema.
• Serializes FunctionCall parts as tool_use and FunctionResponse parts as tool_result content blocks.
• Parses Anthropic tool_use response blocks back into FunctionCall message parts (the runtime's preferred structured path).
• Maps stop_reason: tool_use to FinishReasonEnum::toolCalls() and declares the functionDeclarations supported option.

Verification

New headless smoke test (tests/structured-tools-smoke.php) mocks the HTTP transporter and asserts, with 14 passing assertions:

• the outgoing request declares the tool with name/description/input_schema
• prior FunctionCall/FunctionResponse parts serialize to tool_use/tool_result
• the response tool_use parses into a FunctionCall part with decoded args and preserved id

OK: 14 structured-tools assertions passed.

Also passing: php -l on all provider files, tests/carried-claude-code-plugin.sh, tests/homeboy-codebox-canary.sh, tests/agents-md-guidance.sh, git diff --check.

Related upstream fixes from this work

• fix: expose writable workspace tools for read-write Codebox agent tasks homeboy-extensions#1190 — expose writable workspace tools for read-write Codebox agent tasks
• Parse function_call-wrapped and bare JSON tool calls Automattic/agents-api#317 — parse function_call-wrapped and bare JSON tool calls (text fallback hardening)

[chubes4]

Update: empty tool_use input fix + full chain verified

Commit 8d1a9a6 fixes an Anthropic 400 (tool_use.input: Input should be an object): a serialized assistant tool call with empty/list-shaped arguments was encoding as [] instead of {}. Now coerced to a JSON object, with a smoke assertion (15/15 structured-tools assertions pass).

End-to-end status across the full chain

With the synced runtime (data-machine main + agents-api dev-main + the writable-tools and projection fixes), the structured tool-calling path now reaches Anthropic and the model emits real tool_use blocks. The final runtime gap was that the write workspace tools were never projected as model-facing tools — fixed in Extra-Chill/data-machine-code#606.

Related fixes that make Codebox coding agents work end-to-end:

• fix: expose writable workspace tools for read-write Codebox agent tasks homeboy-extensions#1190 — expose writable workspace tools in the sandbox tool policy
• Project write and git workspace tools for coding agents data-machine-code#606 — project write/git workspace tools (opt-in) so they reach the model
• This PR (Add Claude Code provider plugin #197) — Claude Code provider: structured tool calling + empty-input object encoding

Remaining note

Opus 4.8 is non-deterministic about emitting a structured tool_use vs. narrating the action in prose; when it narrates, the write does not execute. The provider/runtime plumbing is correct (verified by a real tool_use round-trip and 15/15 headless assertions); the remaining item is model/prompt behavior, tracked separately from this provider PR.