feat(provider): add Modal as a built-in provider for GLM-5

[chindris-mihai-alexandru]

Summary

Add Modal as a built-in provider in ForgeCode, enabling access to Z.ai's GLM-5 (745B parameter) flagship open-source model hosted on Modal's infrastructure.

Motivation

Modal recently partnered with Z.ai to offer GLM-5 via an OpenAI-compatible API endpoint. GLM-5 is a frontier open-weights MoE model designed for long-horizon agents and systems engineering, matching proprietary model performance. Modal offers free access until April 30th, 2026.

Adding Modal as a provider allows ForgeCode users to:

• Try GLM-5 for free — No cost until end of April 2026
• Use a frontier open model — 745B params, 192K context, MIT licensed
• Zero config — Just forge provider login modal with a Modal API token

Changes

crates/forge_repo/src/provider/provider.json

• Added modal provider entry with OpenAI-compatible response type
• API endpoint: https://api.us-west-2.modal.direct/v1/chat/completions
• Model: zai-org/GLM-5-FP8 (hardcoded, as Modal hosts a single model)
• Auth: API key (MODAL_API_KEY)

crates/forge_domain/src/provider.rs

• Added ProviderId::MODAL constant
• Added "modal" to built_in_providers() list
• Added "Modal" display name mapping
• Added "modal" to FromStr implementation
• Added 3 unit tests: test_modal_from_str, test_modal_display_name, test_modal_in_built_in_providers

Testing

• ✅ cargo check -p forge_domain passes
• ✅ All 23 provider tests pass (3 new for Modal)
• ✅ JSON validation passes

How to Use

1. Get a free token at modal.com/glm-5-endpoint
2. forge provider login modal → enter your token
3. Select GLM-5 via /model

References

• Modal GLM-5 Blog Post
• Modal GLM-5 Endpoint
• Z.ai GLM-5 Release

🌸 Generated with AdaL

[Copilot]

Pull request overview

Adds Modal as a built-in provider so ForgeCode can use Z.ai’s GLM-5 via Modal’s OpenAI-compatible chat completions endpoint.

Changes:

• Added a new modal provider entry in the embedded provider catalog, with a hardcoded GLM-5 model configuration.
• Extended ProviderId to include MODAL, with parsing, display-name mapping, and built-in provider listing updates.
• Added unit tests covering modal parsing, display name, and inclusion in built-in providers.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
crates/forge_repo/src/provider/provider.json	Adds the modal provider config pointing at Modal’s OpenAI-compatible chat completions URL with a hardcoded GLM-5 model.
crates/forge_domain/src/provider.rs	Registers ProviderId::MODAL and adds tests ensuring correct string parsing, display name, and built-in listing inclusion.

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[chindris-mihai-alexandru]

Local Testing Verified ✅

Successfully tested the Modal provider integration locally:

$ forge provider list | grep -A 4 MODAL
MODAL
  name      Modal
  id        modal
  host      api.us-west-2.modal.direct
  logged in [yes]

Modal API responds correctly with GLM-5:

• Model: zai-org/GLM-5-FP8
• Context: 192K tokens
• Reasoning: Returns reasoning_content field
• Latency: ~50s cold start, then fast responses

ForgeCode joins Claude Code, OpenCode, OpenClaw, and Vercel AI SDK as frontends with native Modal/GLM-5 support.

Co-Authored-By: ForgeCode noreply@forgecode.dev