How to Use Shared Models in Codex, Claude Code, OpenCode, and More

A Fasten Share consumer can search online model nodes, select a producer, and generate a compatible service endpoint. You do not need the producer’s upstream credential. Every request uses a Fasten Share consumer API key that belongs to your own account.

The client can also prepare configuration for Codex, Claude Code, OpenCode, OpenClaw, Hermes, and Pi. Whether a tool is available depends on the protocol and compatible capabilities published by a producer node, not simply on a familiar-looking model name.

Create a consumer API key

Install Fasten Share from the download page, sign in, and create or select a consumer API key.

This key authenticates calls to the Fasten Share service. It is entirely separate from a producer’s upstream API key. Protect it like any other API credential:

• keep it out of chats, support screenshots, and public repositories;
• avoid reusing it permanently across untrusted devices;
• revoke and recreate it if exposure is possible;
• understand the encryption and access policy of any service that syncs your configuration files.

Find and evaluate a model node

Search the consumer node list by model, protocol, or keyword. Do not choose by model name alone. Check:

• whether the protocol meets the tool requirement, such as OpenAI Responses or Anthropic Messages;
• whether the node is currently online and healthy;
• which consumer tools the producer declares as supported;
• whether the credit multiplier matches your expectations;
• recent three-month ratings and your follow relationship;
• whether your account has enough consumer credits for the call.

Several producers may publish the same model name with different upstream implementations, latency, multipliers, and feature limits. Validate with a small request before starting a long task.

Generate an endpoint or curl command

After selecting a producer, the client generates a Fasten Share service URL containing the protocol, model, and producer identity. A general request also includes your consumer key:

curl "https://node.fastenshare.com/api/v1/inference/PROTOCOL/MODEL/PRODUCER/PATH" \
  -H "Authorization: Bearer FASTEN_CONSUMER_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"MODEL","messages":[{"role":"user","content":"reply with OK"}]}'

Do not guess the encoded model, producer ID, or final path manually. Copy the command generated by the current client to avoid protocol and version-prefix mistakes.

Use the tool configuration assistant

Codex

Codex normally needs OpenAI Responses-style behavior. Select a node that advertises Codex support and a suitable protocol, then let the client prepare its configuration. Some nodes convert Chat Completions to Responses. Converted nodes may not support stateful sessions, hosted tools, background mode, Responses WebSocket, or every tool feature.

Choose a native Responses node when your task relies on those capabilities, and run a small test first. The assistant attempts to prevent an existing OAuth state from overriding the new API key, but you should still understand and back up the current tool configuration before changing it.

Claude Code

Claude Code should use a node that advertises Claude support over an Anthropic-compatible protocol. The key written into the tool is your Fasten Share consumer key, not the producer’s upstream x-api-key.

If the tool continues to use an old OAuth login or another provider, follow the client’s conflict-cleanup guidance and verify that the generated endpoint uses the official Fasten Share service domain.

OpenCode, OpenClaw, Hermes, and Pi

These tools use different provider and configuration formats. Fasten Share only offers a configuration option when the selected node advertises the matching tool. Before automatic configuration:

1. Close tool instances that may write the same file.
2. Review the target path and backup information shown by the client.
3. Reopen the tool after configuration.
4. Send a short request to validate the model, protocol, and streaming response.
5. Restore the backup if you need to return to the old provider.

Pi registers a Fasten Share provider while retaining existing settings. Other integrations also try to preserve current configuration, but a manual backup remains a sensible precaution.

Know which content and credentials travel where

Your consumer API key is sent to the Fasten Share service for authentication. Prompts, tool input, and model responses also pass through the service so it can route, stream, meter, and settle the call.

The producer’s upstream API key is never sent to you or stored by the service. It is injected on the producer device when the client calls the real backend. Separating the two credentials lowers direct exposure risk, but it does not mean business content bypasses the central service.

Do not assume that a third-party producer node carries the same data-handling commitments as an enterprise private deployment. Decide whether to use it based on data sensitivity, platform rules, producer trust signals, and your organization’s requirements.

Common errors

The tool returns 401 or unauthorized

Confirm that the request uses an active Fasten Share consumer API key with the exact header format generated by the client. Do not paste an upstream key from a producer example.

The model or path no longer exists

Copy the current endpoint from the client again. A producer may have changed the model, protocol, or version prefix, so an older URL may no longer be valid.

The tool ignores the new configuration

Look for OAuth state, environment variables, or higher-priority configuration that overrides the file. Use the assistant’s conflict detection and backup workflow.

Basic chat works, but tool calls fail

The node may only provide text inference, or protocol conversion may omit the feature you need. Review its declared tool compatibility and compare it with a native-protocol node.

Streaming stops or latency is too high

Try another online node with stronger recent trust signals and compare a short request. When reporting a recurring error, include the time and protocol but never the full API key.

Recommended first validation

1. Complete a short request with the generated curl command.
2. Confirm that consumer credit usage matches the current multiplier shown by the client.
3. Use the assistant to configure the target tool.
4. Restart the tool and run a minimal task.
5. Only then run a long-context, tool-calling, or coding workflow.

If the relationship between producers, consumers, and service routing is still unfamiliar, read What Is Fasten Share? and the quick start first.