What this error means

tokens_per_min (TPM) rate limit exceeded — single call with 100k context tokens consumes large fraction of TPM budget is a OpenAI API failure pattern reported for developers trying to understand and manage openai tpm (tokens per minute) limits when using long-context models like gpt-5.4/gpt-5.5 with 100k+ input tokens. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Respan guide (May 2026) documents new TPM dimension introduced by OpenAI as primary constraint for long-context workloads. A single GPT-5.5 call with 100k context can exhaust most of a Tier 1 account's TPM budget immediately. Tokens reserved at submission time block remaining budget. Per-process token bucket fails in multi-process deployments. Covers estimated token tracking with tiktoken before sending.

Common causes

  • Respan guide (May 2026) documents new TPM dimension introduced by OpenAI as primary constraint for long-context workloads. A single GPT-5.5 call with 100k context can exhaust most of a Tier 1 account's TPM budget immediately. Tokens reserved at submission time block remaining budget. Per-process token bucket fails in multi-process deployments. Covers estimated token tracking with tiktoken before sending.

Quick fixes

  1. Confirm the exact error signature matches tokens_per_min (TPM) rate limit exceeded — single call with 100k context tokens consumes large fraction of TPM budget.
  2. Check the OpenAI API account, local tool state, and provider configuration involved in the failing workflow.
  3. Reduce request pressure, check quota or plan limits, and retry with backoff instead of immediate repeated requests.

Platform/tool-specific checks

  • Verify the command, editor, extension, or API client that produced the error.
  • Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
  • Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

  1. Capture the exact error message and the command, editor action, or request that triggered it.
  2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
  3. Review the source evidence below and compare it with your environment.
  4. Apply one change at a time and rerun the smallest failing action.
  5. Keep the working fix documented for the team or deployment environment.

How to prevent it

  • Keep provider/tool configuration documented.
  • Record non-secret diagnostics such as tool version, provider name, model name, and command path.
  • Add a lightweight check before CI or production workflows depend on the tool.