Create a Text Completion
Deprecated: Use the Messages API instead.
[Legacy] Create a Text Completion.
The Text Completions API is a legacy API. We recommend using the Messages API going forward.
Future models and features will not be compatible with Text Completions. See our migration guide for guidance in migrating from Text Completions to Messages.
Parameters
--max-tokens-to-sample: numberThe maximum number of tokens to generate before stopping.
The maximum number of tokens to generate before stopping.
Note that our models may stop before reaching this maximum. This parameter only specifies the absolute maximum number of tokens to generate.
--model: "claude-haiku-5-5" or "claude-sonnet-5-5" or "claude-fable-5-1" or 17 more or stringThe model that will complete your prompt.
The model that will complete your prompt.
See models for additional details and options.
--prompt: stringThe prompt that you want Claude to complete.
The prompt that you want Claude to complete.
For proper response generation you will need to format your prompt using alternating `
Human:and
Assistant:` conversational turns. For example:
"
Human: {userQuestion}
Assistant:"
See prompt validation and our guide to prompt design for more details.
An object describing metadata about the request.
--stop-sequence: optional array of stringSequences that will cause the model to stop generating.
Sequences that will cause the model to stop generating.
Our models stop on `"
Human:"`, and may include additional built-in stop sequences in the future. By providing the stop_sequences parameter, you may include additional strings that will cause the model to stop generating.
--workspace-id: optional stringHeader parameterOptional header to select the Workspace for this request. The value is a Workspace ID (for example, wrkspc_011CZkZaBF1tNoB5wlCeusgy).
Optional header to select the Workspace for this request. The value is a Workspace ID (for example, wrkspc_011CZkZaBF1tNoB5wlCeusgy).
Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace.
--temperature: optional numberDeprecatedAmount of randomness injected into the response.
Amount of randomness injected into the response.
Defaults to 1.0. Ranges from 0.0 to 1.0. Use temperature closer to 0.0 for analytical / multiple choice, and closer to 1.0 for creative and generative tasks.
Note that even with temperature of 0.0, the results will not be fully deterministic.
--top-k: optional numberDeprecatedOnly sample from the top K options for each subsequent token.
Only sample from the top K options for each subsequent token.
Used to remove "long tail" low probability responses. Learn more technical details here.
Recommended for advanced use cases only.
--top-p: optional numberDeprecatedUse nucleus sampling.
Use nucleus sampling.
In nucleus sampling, we compute the cumulative distribution over all the options for each subsequent token in decreasing probability order and cut it off once it reaches a particular probability specified by top_p.
Recommended for advanced use cases only.
--beta: optional array of AnthropicBetaHeader parameterDeprecatedOptional header to specify the beta version(s) you want to use.
Optional header to specify the beta version(s) you want to use.
Returns
completion: object{ type: "completion", id, completion, 2 more }
type: "completion"Object type.
Object type.
For Text Completions, this is always "completion".
id: stringUnique object identifier.
Unique object identifier.
The format and length of IDs may change over time.
The resulting completion up to and excluding the stop sequences.
model: "claude-haiku-5-5" or "claude-sonnet-5-5" or "claude-fable-5-1" or 17 more or stringThe model that will complete your prompt.
The model that will complete your prompt.
See models for additional details and options.
Fastest model for high-volume, real-time tasks
Efficient model for coding and agents
Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
Powerful intelligence for coding, knowledge work, and long-running agents
Our most capable model for cybersecurity and biology research, available through trusted access programs
Efficient model for coding and agents
Next generation of intelligence for the hardest knowledge work and coding problems
Most capable model for cybersecurity and biology research
Powerful intelligence for long-running agents and coding
Powerful intelligence for long-running agents and coding
Powerful intelligence for long-running agents and coding
Powerful intelligence for long-running agents and coding
Best combination of speed and intelligence
Powerful intelligence for long-running agents and coding
Powerful intelligence for long-running agents and coding
"claude-mythos-preview"DeprecatedNew class of intelligence, strongest in coding and cybersecurity
New class of intelligence, strongest in coding and cybersecurity
"claude-sonnet-4-5"DeprecatedHigh-performance model for agents and coding
High-performance model for agents and coding
"claude-sonnet-4-5-20250929"DeprecatedHigh-performance model for agents and coding
High-performance model for agents and coding
stop_reason: stringThe reason that we stopped.
The reason that we stopped.
This may be one the following values:
"stop_sequence": we reached a stop sequence — either provided by you via thestop_sequencesparameter, or a stop sequence built into the model"max_tokens": we exceededmax_tokens_to_sampleor the model's maximum
ant completions create \
--api-key my-anthropic-api-key \
--max-tokens-to-sample 256 \
--model claude-haiku-5-5 \
--prompt '
Human: Hello, world!
Assistant:'{
"id": "compl_018CKm6gsux7P8yMcwZbeCPw",
"completion": " Hello! My name is Claude.",
"model": "claude-2.1",
"stop_reason": "stop_sequence",
"type": "completion"
}Returns Examples
{
"id": "compl_018CKm6gsux7P8yMcwZbeCPw",
"completion": " Hello! My name is Claude.",
"model": "claude-2.1",
"stop_reason": "stop_sequence",
"type": "completion"
}